Fossil

  completionCursorReset(pCur);
  if( idxNum & 1 ){
    pCur->nPrefix = sqlite3_value_bytes(argv[iArg]);
    if( pCur->nPrefix>0 ){
      pCur->zPrefix = sqlite3_mprintf("%s", sqlite3_value_text(argv[iArg]));
      if( pCur->zPrefix==0 ) return SQLITE_NOMEM;
    }
    iArg = 1;
  }
  if( idxNum & 2 ){
    pCur->nLine = sqlite3_value_bytes(argv[iArg]);
    if( pCur->nLine>0 ){
      pCur->zLine = sqlite3_mprintf("%s", sqlite3_value_text(argv[iArg]));
      if( pCur->zLine==0 ) return SQLITE_NOMEM;
    }

  }
  if( pCur->zLine!=0 && pCur->zPrefix==0 ){
    int i = pCur->nLine;
    while( i>0 && (isalnum(pCur->zLine[i-1]) || pCur->zLine[i-1]=='_') ){
      i--;
    }
    pCur->nPrefix = pCur->nLine - i;

**
** See also: [sqlite3_libversion()],
** [sqlite3_libversion_number()], [sqlite3_sourceid()],
** [sqlite_version()] and [sqlite_source_id()].
*/
#define SQLITE_VERSION        "3.25.0"
#define SQLITE_VERSION_NUMBER 3025000
#define SQLITE_SOURCE_ID      "2018-08-30 01:52:10 58078c0d2647a194279fa80e032670441b296ffc3acee692901faa5beca460b7"

/*
** CAPI3REF: Run-Time Library Version Numbers
** KEYWORDS: sqlite3_version sqlite3_sourceid
**
** These interfaces provide the same information as the [SQLITE_VERSION],
** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros

#define SQLITE_INDEX_CONSTRAINT_GLOB      66
#define SQLITE_INDEX_CONSTRAINT_REGEXP    67
#define SQLITE_INDEX_CONSTRAINT_NE        68
#define SQLITE_INDEX_CONSTRAINT_ISNOT     69
#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
#define SQLITE_INDEX_CONSTRAINT_ISNULL    71
#define SQLITE_INDEX_CONSTRAINT_IS        72
#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150

/*
** CAPI3REF: Register A Virtual Table Implementation
** METHOD: sqlite3
**
** ^These routines are used to register a new [virtual table module] name.
** ^Module names must be registered before

/*
** Set the SQLITE_PTRSIZE macro to the number of bytes in a pointer
*/
#ifndef SQLITE_PTRSIZE
# if defined(__SIZEOF_POINTER__)
#   define SQLITE_PTRSIZE __SIZEOF_POINTER__
# elif defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
       defined(_M_ARM)   || defined(__arm__)    || defined(__x86)   ||    \
      (defined(__TOS_AIX__) && !defined(__64BIT__))
#   define SQLITE_PTRSIZE 4
# else
#   define SQLITE_PTRSIZE 8
# endif
#endif

/* The uptr type is an unsigned integer large enough to hold a pointer

** -DSQLITE_BYTEORDER=0 is set, then byte-order is determined
** at run-time.
*/
#ifndef SQLITE_BYTEORDER
# if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
     defined(__arm__)  || defined(_M_ARM64)
#   define SQLITE_BYTEORDER    1234
# elif defined(sparc)    || defined(__ppc__)
#   define SQLITE_BYTEORDER    4321
# else
#   define SQLITE_BYTEORDER 0
# endif
#endif

SQLITE_PRIVATE void sqlite3BitvecClear(Bitvec*, u32, void*);
SQLITE_PRIVATE void sqlite3BitvecDestroy(Bitvec*);
SQLITE_PRIVATE u32 sqlite3BitvecSize(Bitvec*);
#ifndef SQLITE_UNTESTABLE
SQLITE_PRIVATE int sqlite3BitvecBuiltinTest(int,int*);
#endif

SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3*);
SQLITE_PRIVATE void sqlite3RowSetDelete(void*);
SQLITE_PRIVATE void sqlite3RowSetClear(void*);
SQLITE_PRIVATE void sqlite3RowSetInsert(RowSet*, i64);
SQLITE_PRIVATE int sqlite3RowSetTest(RowSet*, int iBatch, i64);
SQLITE_PRIVATE int sqlite3RowSetNext(RowSet*, i64*);

SQLITE_PRIVATE void sqlite3CreateView(Parse*,Token*,Token*,Token*,ExprList*,Select*,int,int);

#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_VIRTUALTABLE)

  i64 *anExec;            /* Event counters from parent frame */
  Mem *aMem;              /* Array of memory cells for parent frame */
  VdbeCursor **apCsr;     /* Array of Vdbe cursors for parent frame */
  u8 *aOnce;              /* Bitmask used by OP_Once */
  void *token;            /* Copy of SubProgram.token */
  i64 lastRowid;          /* Last insert rowid (sqlite3.lastRowid) */
  AuxData *pAuxData;      /* Linked list of auxdata allocations */
#if SQLITE_DEBUG
  u32 iFrameMagic;        /* magic number for sanity checking */
#endif
  int nCursor;            /* Number of entries in apCsr */
  int pc;                 /* Program Counter in parent (calling) frame */
  int nOp;                /* Size of aOp array */
  int nMem;               /* Number of entries in aMem */
  int nChildMem;          /* Number of memory cells for child frame */
  int nChildCsr;          /* Number of cursors for child frame */
  int nChange;            /* Statement changes (Vdbe.nChange)     */
  int nDbChange;          /* Value of db->nChange */
};

/* Magic number for sanity checking on VdbeFrame objects */
#define SQLITE_FRAME_MAGIC 0x879fb71e

/*
** Return a pointer to the array of registers allocated for use
** by a VdbeFrame.
*/
#define VdbeFrameMem(p) ((Mem *)&((u8 *)p)[ROUND8(sizeof(VdbeFrame))])

/*
** Internally, the vdbe manipulates nearly all SQL values as Mem
** structures. Each Mem struct may cache multiple representations (string,
** integer etc.) of the same value.
*/
struct sqlite3_value {
  union MemValue {
    double r;           /* Real value used when MEM_Real is set in flags */
    i64 i;              /* Integer value used when MEM_Int is set in flags */
    int nZero;          /* Extra zero bytes when MEM_Zero and MEM_Blob set */
    const char *zPType; /* Pointer type when MEM_Term|MEM_Subtype|MEM_Null */
    FuncDef *pDef;      /* Used only when flags==MEM_Agg */


  } u;
  u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
  u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
  u8  eSubtype;       /* Subtype for this value */
  int n;              /* Number of characters in string value, excluding '\0' */
  char *z;            /* String or BLOB value */
  /* ShallowCopy only needs to copy the information above */

*/
#define MEM_Null      0x0001   /* Value is NULL (or a pointer) */
#define MEM_Str       0x0002   /* Value is a string */
#define MEM_Int       0x0004   /* Value is an integer */
#define MEM_Real      0x0008   /* Value is a real number */
#define MEM_Blob      0x0010   /* Value is a BLOB */
#define MEM_AffMask   0x001f   /* Mask of affinity bits */
/* Available          0x0020   */
/* Available          0x0040   */
#define MEM_Undefined 0x0080   /* Value is undefined */
#define MEM_Cleared   0x0100   /* NULL set by OP_Null, not from data */
#define MEM_TypeMask  0xc1ff   /* Mask of type bits */


/* Whenever Mem contains a valid string or blob representation, one of
** the following flags must be set to determine the memory management

  #define MEM_Zero 0x0000
#endif

/* Return TRUE if Mem X contains dynamically allocated content - anything
** that needs to be deallocated to avoid a leak.
*/
#define VdbeMemDynamic(X)  \
  (((X)->flags&(MEM_Agg|MEM_Dyn))!=0)

/*
** Clear any existing type flags from a Mem and replace them with f
*/
#define MemSetTypeFlag(p, f) \
   ((p)->flags = ((p)->flags&~(MEM_TypeMask|MEM_Zero))|f)

#else
SQLITE_PRIVATE   void sqlite3VdbeMemSetDouble(Mem*, double);
#endif
SQLITE_PRIVATE void sqlite3VdbeMemSetPointer(Mem*, void*, const char*, void(*)(void*));
SQLITE_PRIVATE void sqlite3VdbeMemInit(Mem*,sqlite3*,u16);
SQLITE_PRIVATE void sqlite3VdbeMemSetNull(Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemSetZeroBlob(Mem*,int);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE int sqlite3VdbeMemIsRowSet(const Mem*);
#endif
SQLITE_PRIVATE int sqlite3VdbeMemSetRowSet(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemStringify(Mem*, u8, u8);
SQLITE_PRIVATE i64 sqlite3VdbeIntValue(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemIntegerify(Mem*);
SQLITE_PRIVATE double sqlite3VdbeRealValue(Mem*);
SQLITE_PRIVATE int sqlite3VdbeBooleanValue(Mem*, int ifNull);
SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemRealify(Mem*);
SQLITE_PRIVATE int sqlite3VdbeMemNumerify(Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemCast(Mem*,u8,u8);
SQLITE_PRIVATE int sqlite3VdbeMemFromBtree(BtCursor*,u32,u32,Mem*);
SQLITE_PRIVATE void sqlite3VdbeMemRelease(Mem *p);
SQLITE_PRIVATE int sqlite3VdbeMemFinalize(Mem*, FuncDef*);
#ifndef SQLITE_OMIT_WINDOWFUNC
SQLITE_PRIVATE int sqlite3VdbeMemAggValue(Mem*, Mem*, FuncDef*);
#endif
SQLITE_PRIVATE const char *sqlite3OpcodeName(int);
SQLITE_PRIVATE int sqlite3VdbeMemGrow(Mem *pMem, int n, int preserve);
SQLITE_PRIVATE int sqlite3VdbeMemClearAndResize(Mem *pMem, int n);
SQLITE_PRIVATE int sqlite3VdbeCloseStatement(Vdbe *, int);
#ifdef SQLITE_DEBUG
SQLITE_PRIVATE int sqlite3VdbeFrameIsValid(VdbeFrame*);
#endif
SQLITE_PRIVATE void sqlite3VdbeFrameMemDel(void*);      /* Destructor on Mem */
SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame*); /* Actually deletes the Frame */
SQLITE_PRIVATE int sqlite3VdbeFrameRestore(VdbeFrame *);
#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
SQLITE_PRIVATE void sqlite3VdbePreUpdateHook(Vdbe*,VdbeCursor*,int,const char*,Table*,i64,int);
#endif
SQLITE_PRIVATE int sqlite3VdbeTransferError(Vdbe *p);

SQLITE_PRIVATE int sqlite3VdbeSorterInit(sqlite3 *, int, VdbeCursor *);

/*
** Allowed values for RowSet.rsFlags
*/
#define ROWSET_SORTED  0x01   /* True if RowSet.pEntry is sorted */
#define ROWSET_NEXT    0x02   /* True if sqlite3RowSetNext() has been called */

/*
** Allocate a RowSet object.  Return NULL if a memory allocation





** error occurs.



*/
SQLITE_PRIVATE RowSet *sqlite3RowSetInit(sqlite3 *db){
  RowSet *p = sqlite3DbMallocRawNN(db, sizeof(*p));
  if( p ){
    int N = sqlite3DbMallocSize(db, p);
    p->pChunk = 0;
    p->db = db;
    p->pEntry = 0;
    p->pLast = 0;
    p->pForest = 0;
    p->pFresh = (struct RowSetEntry*)(ROUND8(sizeof(*p)) + (char*)p);
    p->nFresh = (u16)((N - ROUND8(sizeof(*p)))/sizeof(struct RowSetEntry));
    p->rsFlags = ROWSET_SORTED;
    p->iBatch = 0;
  }
  return p;
}

/*
** Deallocate all chunks from a RowSet.  This frees all memory that
** the RowSet has allocated over its lifetime.  This routine is
** the destructor for the RowSet.
*/
SQLITE_PRIVATE void sqlite3RowSetClear(void *pArg){
  RowSet *p = (RowSet*)pArg;
  struct RowSetChunk *pChunk, *pNextChunk;
  for(pChunk=p->pChunk; pChunk; pChunk = pNextChunk){
    pNextChunk = pChunk->pNextChunk;
    sqlite3DbFree(p->db, pChunk);
  }
  p->pChunk = 0;
  p->nFresh = 0;
  p->pEntry = 0;
  p->pLast = 0;
  p->pForest = 0;
  p->rsFlags = ROWSET_SORTED;
}

/*
** Deallocate all chunks from a RowSet.  This frees all memory that
** the RowSet has allocated over its lifetime.  This routine is
** the destructor for the RowSet.
*/
SQLITE_PRIVATE void sqlite3RowSetDelete(void *pArg){
  sqlite3RowSetClear(pArg);
  sqlite3DbFree(((RowSet*)pArg)->db, pArg);
}

/*
** Allocate a new RowSetEntry object that is associated with the
** given RowSet.  Return a pointer to the new and completely uninitialized
** objected.
**
** In an OOM situation, the RowSet.db->mallocFailed flag is set and this

          *pChanged = bChanged;
        }else{
          rc = SQLITE_BUSY_SNAPSHOT;
        }

        /* Release the shared CKPT lock obtained above. */
        walUnlockShared(pWal, WAL_CKPT_LOCK);
        pWal->minFrame = 1;
      }


      if( rc!=SQLITE_OK ){
        sqlite3WalEndReadTransaction(pWal);
      }
    }

  assert( (p->flags & MEM_Dyn)==0 || p->szMalloc==0 );

  /* Cannot be both MEM_Int and MEM_Real at the same time */
  assert( (p->flags & (MEM_Int|MEM_Real))!=(MEM_Int|MEM_Real) );

  if( p->flags & MEM_Null ){
    /* Cannot be both MEM_Null and some other type */
    assert( (p->flags & (MEM_Int|MEM_Real|MEM_Str|MEM_Blob|MEM_Agg))==0 );


    /* If MEM_Null is set, then either the value is a pure NULL (the usual
    ** case) or it is a pointer set using sqlite3_bind_pointer() or
    ** sqlite3_result_pointer().  If a pointer, then MEM_Term must also be
    ** set.
    */
    if( (p->flags & (MEM_Term|MEM_Subtype))==(MEM_Term|MEM_Subtype) ){

** SQLITE_NOMEM may be returned if a malloc() fails during conversion
** between formats.
*/
SQLITE_PRIVATE int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
#ifndef SQLITE_OMIT_UTF16
  int rc;
#endif
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  assert( desiredEnc==SQLITE_UTF8 || desiredEnc==SQLITE_UTF16LE
           || desiredEnc==SQLITE_UTF16BE );
  if( !(pMem->flags&MEM_Str) || pMem->enc==desiredEnc ){
    return SQLITE_OK;
  }
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
#ifdef SQLITE_OMIT_UTF16

** If the bPreserve argument is true, then copy of the content of
** pMem->z into the new allocation.  pMem must be either a string or
** blob if bPreserve is true.  If bPreserve is false, any prior content
** in pMem->z is discarded.
*/
SQLITE_PRIVATE SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
  assert( sqlite3VdbeCheckMemInvariants(pMem) );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  testcase( pMem->db==0 );

  /* If the bPreserve flag is set to true, then the memory cell must already
  ** contain a valid string or blob value.  */
  assert( bPreserve==0 || pMem->flags&(MEM_Blob|MEM_Str) );
  testcase( bPreserve && pMem->z==0 );

** Change pMem so that its MEM_Str or MEM_Blob value is stored in
** MEM.zMalloc, where it can be safely written.
**
** Return SQLITE_OK on success or SQLITE_NOMEM if malloc fails.
*/
SQLITE_PRIVATE int sqlite3VdbeMemMakeWriteable(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  if( (pMem->flags & (MEM_Str|MEM_Blob))!=0 ){
    if( ExpandBlob(pMem) ) return SQLITE_NOMEM;
    if( pMem->szMalloc==0 || pMem->z!=pMem->zMalloc ){
      int rc = vdbeMemAddTerminator(pMem);
      if( rc ) return rc;
    }
  }

** blob stored in dynamically allocated space.
*/
#ifndef SQLITE_OMIT_INCRBLOB
SQLITE_PRIVATE int sqlite3VdbeMemExpandBlob(Mem *pMem){
  int nByte;
  assert( pMem->flags & MEM_Zero );
  assert( pMem->flags&MEM_Blob );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );

  /* Set nByte to the number of bytes required to store the expanded blob. */
  nByte = pMem->n + pMem->u.nZero;
  if( nByte<=0 ){
    nByte = 1;
  }

  int fg = pMem->flags;
  const int nByte = 32;

  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( !(fg&MEM_Zero) );
  assert( !(fg&(MEM_Str|MEM_Blob)) );
  assert( fg&(MEM_Int|MEM_Real) );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  assert( EIGHT_BYTE_ALIGNMENT(pMem) );


  if( sqlite3VdbeMemClearAndResize(pMem, nByte) ){
    pMem->enc = 0;
    return SQLITE_NOMEM_BKPT;
  }

  assert( VdbeMemDynamic(p) );
  if( p->flags&MEM_Agg ){
    sqlite3VdbeMemFinalize(p, p->u.pDef);
    assert( (p->flags & MEM_Agg)==0 );
    testcase( p->flags & MEM_Dyn );
  }
  if( p->flags&MEM_Dyn ){

    assert( p->xDel!=SQLITE_DYNAMIC && p->xDel!=0 );
    p->xDel((void *)p->z);






  }
  p->flags = MEM_Null;
}

/*
** Release memory held by the Mem p, both external memory cleared
** by p->xDel and memory in p->zMalloc.

/*
** The MEM structure is already a MEM_Real.  Try to also make it a
** MEM_Int if we can.
*/
SQLITE_PRIVATE void sqlite3VdbeIntegerAffinity(Mem *pMem){
  i64 ix;
  assert( pMem->flags & MEM_Real );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  ix = doubleToInt64(pMem->u.r);

  /* Only mark the value as an integer if
  **

}

/*
** Convert pMem to type integer.  Invalidate any prior representations.
*/
SQLITE_PRIVATE int sqlite3VdbeMemIntegerify(Mem *pMem){
  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  assert( EIGHT_BYTE_ALIGNMENT(pMem) );

  pMem->u.i = sqlite3VdbeIntValue(pMem);
  MemSetTypeFlag(pMem, MEM_Int);
  return SQLITE_OK;
}

  if( !sqlite3IsNaN(val) ){
    pMem->u.r = val;
    pMem->flags = MEM_Real;
  }
}
#endif

#ifdef SQLITE_DEBUG
/*
** Return true if the Mem holds a RowSet object.  This routine is intended
** for use inside of assert() statements.
*/
SQLITE_PRIVATE int sqlite3VdbeMemIsRowSet(const Mem *pMem){
  return (pMem->flags&(MEM_Blob|MEM_Dyn))==(MEM_Blob|MEM_Dyn)
         && pMem->xDel==sqlite3RowSetDelete;
}
#endif

/*
** Delete any previous value and set the value of pMem to be an
** empty boolean index.
**
** Return SQLITE_OK on success and SQLITE_NOMEM if a memory allocation
** error occurs.
*/
SQLITE_PRIVATE int sqlite3VdbeMemSetRowSet(Mem *pMem){
  sqlite3 *db = pMem->db;
  RowSet *p;
  assert( db!=0 );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  sqlite3VdbeMemRelease(pMem);
  p = sqlite3RowSetInit(db);
  if( p==0 ) return SQLITE_NOMEM;
  pMem->z = (char*)p;
  pMem->flags = MEM_Blob|MEM_Dyn;




  pMem->xDel = sqlite3RowSetDelete;

  return SQLITE_OK;

}

/*
** Return true if the Mem object contains a TEXT or BLOB that is
** too large - whose size exceeds SQLITE_MAX_LENGTH.
*/
SQLITE_PRIVATE int sqlite3VdbeMemTooBig(Mem *p){

*/
static SQLITE_NOINLINE void vdbeClrCopy(Mem *pTo, const Mem *pFrom, int eType){
  vdbeMemClearExternAndSetNull(pTo);
  assert( !VdbeMemDynamic(pTo) );
  sqlite3VdbeMemShallowCopy(pTo, pFrom, eType);
}
SQLITE_PRIVATE void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
  assert( !sqlite3VdbeMemIsRowSet(pFrom) );
  assert( pTo->db==pFrom->db );
  if( VdbeMemDynamic(pTo) ){ vdbeClrCopy(pTo,pFrom,srcType); return; }
  memcpy(pTo, pFrom, MEMCELLSIZE);
  if( (pFrom->flags&MEM_Static)==0 ){
    pTo->flags &= ~(MEM_Dyn|MEM_Static|MEM_Ephem);
    assert( srcType==MEM_Ephem || srcType==MEM_Static );
    pTo->flags |= srcType;
  }
}

/*
** Make a full copy of pFrom into pTo.  Prior contents of pTo are
** freed before the copy is made.
*/
SQLITE_PRIVATE int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
  int rc = SQLITE_OK;

  assert( !sqlite3VdbeMemIsRowSet(pFrom) );
  if( VdbeMemDynamic(pTo) ) vdbeMemClearExternAndSetNull(pTo);
  memcpy(pTo, pFrom, MEMCELLSIZE);
  pTo->flags &= ~MEM_Dyn;
  if( pTo->flags&(MEM_Str|MEM_Blob) ){
    if( 0==(pFrom->flags&MEM_Static) ){
      pTo->flags |= MEM_Ephem;
      rc = sqlite3VdbeMemMakeWriteable(pTo);

  void (*xDel)(void*) /* Destructor function */
){
  int nByte = n;      /* New value for pMem->n */
  int iLimit;         /* Maximum allowed string or blob size */
  u16 flags = 0;      /* New value for pMem->flags */

  assert( pMem->db==0 || sqlite3_mutex_held(pMem->db->mutex) );
  assert( !sqlite3VdbeMemIsRowSet(pMem) );

  /* If z is a NULL pointer, set pMem to contain an SQL NULL. */
  if( !z ){
    sqlite3VdbeMemSetNull(pMem);
    return SQLITE_OK;
  }

  int rc = SQLITE_OK; /* Return code */

  assert( sqlite3BtreeCursorIsValid(pCur) );
  assert( !VdbeMemDynamic(pMem) );

  /* Note: the calls to BtreeKeyFetch() and DataFetch() below assert() 
  ** that both the BtShared and database handle mutexes are held. */
  assert( !sqlite3VdbeMemIsRowSet(pMem) );
  zData = (char *)sqlite3BtreePayloadFetch(pCur, &available);
  assert( zData!=0 );

  if( offset+amt<=available ){
    pMem->z = &zData[offset];
    pMem->flags = MEM_Blob|MEM_Ephem;
    pMem->n = (int)amt;

** Convert it into a string with encoding enc and return a pointer
** to a zero-terminated version of that string.
*/
static SQLITE_NOINLINE const void *valueToText(sqlite3_value* pVal, u8 enc){
  assert( pVal!=0 );
  assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
  assert( !sqlite3VdbeMemIsRowSet(pVal) );
  assert( (pVal->flags & (MEM_Null))==0 );
  if( pVal->flags & (MEM_Blob|MEM_Str) ){
    if( ExpandBlob(pVal) ) return 0;
    pVal->flags |= MEM_Str;
    if( pVal->enc != (enc & ~SQLITE_UTF16_ALIGNED) ){
      sqlite3VdbeChangeEncoding(pVal, enc & ~SQLITE_UTF16_ALIGNED);
    }

** If that is the case, then the result must be aligned on an even byte
** boundary.
*/
SQLITE_PRIVATE const void *sqlite3ValueText(sqlite3_value* pVal, u8 enc){
  if( !pVal ) return 0;
  assert( pVal->db==0 || sqlite3_mutex_held(pVal->db->mutex) );
  assert( (enc&3)==(enc&~SQLITE_UTF16_ALIGNED) );
  assert( !sqlite3VdbeMemIsRowSet(pVal) );
  if( (pVal->flags&(MEM_Str|MEM_Term))==(MEM_Str|MEM_Term) && pVal->enc==enc ){
    assert( sqlite3VdbeMemConsistentDualRep(pVal) );
    return pVal->z;
  }
  if( pVal->flags&MEM_Null ){
    return 0;
  }

SQLITE_PRIVATE int sqlite3Stat4Column(
  sqlite3 *db,                    /* Database handle */
  const void *pRec,               /* Pointer to buffer containing record */
  int nRec,                       /* Size of buffer pRec in bytes */
  int iCol,                       /* Column to extract */
  sqlite3_value **ppVal           /* OUT: Extracted value */
){
  u32 t = 0;                      /* a column type code */
  int nHdr;                       /* Size of the header in the record */
  int iHdr;                       /* Next unread header byte */
  int iField;                     /* Next unread data byte */
  int szField = 0;                /* Size of the current data field */
  int i;                          /* Column index */
  u8 *a = (u8*)pRec;              /* Typecast byte array */
  Mem *pMem = *ppVal;             /* Write result into this Mem object */

  assert( iCol>0 );
  iHdr = getVarint32(a, nHdr);
  if( nHdr>nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT;

**
** If the bPush flag is true, then make this opcode the parent for
** subsequent Explains until sqlite3VdbeExplainPop() is called.
*/
SQLITE_PRIVATE void sqlite3VdbeExplain(Parse *pParse, u8 bPush, const char *zFmt, ...){
  if( pParse->explain==2 ){
    char *zMsg;
    Vdbe *v;
    va_list ap;
    int iThis;
    va_start(ap, zFmt);
    zMsg = sqlite3VMPrintf(pParse->db, zFmt, ap);
    va_end(ap);
    v = pParse->pVdbe;
    iThis = v->nOp;

      ** sqlite3MemRelease() were called from here. With -O2, this jumps
      ** to 6.6 percent. The test case is inserting 1000 rows into a table 
      ** with no indexes using a single prepared INSERT statement, bind() 
      ** and reset(). Inserts are grouped into a transaction.
      */
      testcase( p->flags & MEM_Agg );
      testcase( p->flags & MEM_Dyn );
      testcase( p->xDel==sqlite3VdbeFrameMemDel );
      testcase( p->flags & MEM_RowSet );
      if( p->flags&(MEM_Agg|MEM_Dyn) ){
        sqlite3VdbeMemRelease(p);
      }else if( p->szMalloc ){
        sqlite3DbFreeNN(db, p->zMalloc);
        p->szMalloc = 0;
      }

      p->flags = MEM_Undefined;
    }while( (++p)<pEnd );
  }
}

#ifdef SQLITE_DEBUG
/*
** Verify that pFrame is a valid VdbeFrame pointer.  Return true if it is
** and false if something is wrong.
**
** This routine is intended for use inside of assert() statements only.
*/
SQLITE_PRIVATE int sqlite3VdbeFrameIsValid(VdbeFrame *pFrame){
  if( pFrame->iFrameMagic!=SQLITE_FRAME_MAGIC ) return 0;
  return 1;
}
#endif


/*
** This is a destructor on a Mem object (which is really an sqlite3_value)
** that deletes the Frame object that is attached to it as a blob.
**
** This routine does not delete the Frame right away.  It merely adds the
** frame to a list of frames to be deleted when the Vdbe halts.
*/
SQLITE_PRIVATE void sqlite3VdbeFrameMemDel(void *pArg){
  VdbeFrame *pFrame = (VdbeFrame*)pArg;
  assert( sqlite3VdbeFrameIsValid(pFrame) );
  pFrame->pParent = pFrame->v->pDelFrame;
  pFrame->v->pDelFrame = pFrame;
}


/*
** Delete a VdbeFrame object and its contents. VdbeFrame objects are
** allocated by the OP_Program opcode in sqlite3VdbeExec().
*/
SQLITE_PRIVATE void sqlite3VdbeFrameDelete(VdbeFrame *p){
  int i;
  Mem *aMem = VdbeFrameMem(p);
  VdbeCursor **apCsr = (VdbeCursor **)&aMem[p->nChildMem];
  assert( sqlite3VdbeFrameIsValid(p) );
  for(i=0; i<p->nChildCsr; i++){
    sqlite3VdbeFreeCursor(p->v, apCsr[i]);
  }
  releaseMemArray(aMem, p->nChildMem);
  sqlite3VdbeDeleteAuxData(p->v->db, &p->pAuxData, -1, 0);
  sqlite3DbFree(p->v->db, p);
}

SQLITE_PRIVATE int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
  int f1, f2;
  int combined_flags;

  f1 = pMem1->flags;
  f2 = pMem2->flags;
  combined_flags = f1|f2;
  assert( !sqlite3VdbeMemIsRowSet(pMem1) && !sqlite3VdbeMemIsRowSet(pMem2) );
 
  /* If one value is NULL, it is less than the other. If both values
  ** are NULL, return 0.
  */
  if( combined_flags&MEM_Null ){
    return (f2&MEM_Null) - (f1&MEM_Null);
  }

    printf(" si:%lld", p->u.i);
  }else if( p->flags & MEM_Int ){
    printf(" i:%lld", p->u.i);
#ifndef SQLITE_OMIT_FLOATING_POINT
  }else if( p->flags & MEM_Real ){
    printf(" r:%g", p->u.r);
#endif
  }else if( sqlite3VdbeMemIsRowSet(p) ){
    printf(" (rowset)");
  }else{
    char zBuf[200];
    sqlite3VdbeMemPrettyPrint(p, zBuf);
    printf(" %s", zBuf);
  }
  if( p->flags & MEM_Subtype ) printf(" subtype=0x%02x", p->eSubtype);

**
** An assertion fails if P2 is not an integer.
*/
case OP_RowSetAdd: {       /* in1, in2 */
  pIn1 = &aMem[pOp->p1];
  pIn2 = &aMem[pOp->p2];
  assert( (pIn2->flags & MEM_Int)!=0 );
  if( (pIn1->flags & MEM_Blob)==0 ){
    if( sqlite3VdbeMemSetRowSet(pIn1) ) goto no_mem;

  }
  assert( sqlite3VdbeMemIsRowSet(pIn1) );
  sqlite3RowSetInsert((RowSet*)pIn1->z, pIn2->u.i);
  break;
}

/* Opcode: RowSetRead P1 P2 P3 * *
** Synopsis: r[P3]=rowset(P1)
**
** Extract the smallest value from the RowSet object in P1
** and put that value into register P3.
** Or, if RowSet object P1 is initially empty, leave P3
** unchanged and jump to instruction P2.
*/
case OP_RowSetRead: {       /* jump, in1, out3 */
  i64 val;

  pIn1 = &aMem[pOp->p1];
  assert( (pIn1->flags & MEM_Blob)==0 || sqlite3VdbeMemIsRowSet(pIn1) );
  if( (pIn1->flags & MEM_Blob)==0 
   || sqlite3RowSetNext((RowSet*)pIn1->z, &val)==0
  ){
    /* The boolean index is empty */
    sqlite3VdbeMemSetNull(pIn1);
    VdbeBranchTaken(1,2);
    goto jump_to_p2_and_check_for_interrupt;
  }else{
    /* A value was pulled from the index */

  pIn3 = &aMem[pOp->p3];
  iSet = pOp->p4.i;
  assert( pIn3->flags&MEM_Int );

  /* If there is anything other than a rowset object in memory cell P1,
  ** delete it now and initialize P1 with an empty rowset
  */
  if( (pIn1->flags & MEM_Blob)==0 ){
    if( sqlite3VdbeMemSetRowSet(pIn1) ) goto no_mem;

  }
  assert( sqlite3VdbeMemIsRowSet(pIn1) );
  assert( pOp->p4type==P4_INT32 );
  assert( iSet==-1 || iSet>=0 );
  if( iSet ){
    exists = sqlite3RowSetTest((RowSet*)pIn1->z, iSet, pIn3->u.i);
    VdbeBranchTaken(exists!=0,2);
    if( exists ) goto jump_to_p2;
  }
  if( iSet>=0 ){
    sqlite3RowSetInsert((RowSet*)pIn1->z, pIn3->u.i);
  }
  break;
}


#ifndef SQLITE_OMIT_TRIGGER

    goto abort_due_to_error;
  }

  /* Register pRt is used to store the memory required to save the state
  ** of the current program, and the memory required at runtime to execute
  ** the trigger program. If this trigger has been fired before, then pRt 
  ** is already allocated. Otherwise, it must be initialized.  */
  if( (pRt->flags&MEM_Blob)==0 ){
    /* SubProgram.nMem is set to the number of memory cells used by the 
    ** program stored in SubProgram.aOp. As well as these, one memory
    ** cell is required for each cursor used by the program. Set local
    ** variable nMem (and later, VdbeFrame.nChildMem) to this value.
    */
    nMem = pProgram->nMem + pProgram->nCsr;
    assert( nMem>0 );
    if( pProgram->nCsr==0 ) nMem++;
    nByte = ROUND8(sizeof(VdbeFrame))
              + nMem * sizeof(Mem)
              + pProgram->nCsr * sizeof(VdbeCursor*)
              + (pProgram->nOp + 7)/8;
    pFrame = sqlite3DbMallocZero(db, nByte);
    if( !pFrame ){
      goto no_mem;
    }
    sqlite3VdbeMemRelease(pRt);
    pRt->flags = MEM_Blob|MEM_Dyn;
    pRt->z = (char*)pFrame;
    pRt->n = nByte;
    pRt->xDel = sqlite3VdbeFrameMemDel;

    pFrame->v = p;
    pFrame->nChildMem = nMem;
    pFrame->nChildCsr = pProgram->nCsr;
    pFrame->pc = (int)(pOp - aOp);
    pFrame->aMem = p->aMem;
    pFrame->nMem = p->nMem;
    pFrame->apCsr = p->apCsr;
    pFrame->nCursor = p->nCursor;
    pFrame->aOp = p->aOp;
    pFrame->nOp = p->nOp;
    pFrame->token = pProgram->token;
#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
    pFrame->anExec = p->anExec;
#endif
#ifdef SQLITE_DEBUG
    pFrame->iFrameMagic = SQLITE_FRAME_MAGIC;
#endif

    pEnd = &VdbeFrameMem(pFrame)[pFrame->nChildMem];
    for(pMem=VdbeFrameMem(pFrame); pMem!=pEnd; pMem++){
      pMem->flags = MEM_Undefined;
      pMem->db = db;
    }
  }else{
    pFrame = (VdbeFrame*)pRt->z;
    assert( pRt->xDel==sqlite3VdbeFrameMemDel );
    assert( pProgram->nMem+pProgram->nCsr==pFrame->nChildMem 
        || (pProgram->nCsr==0 && pProgram->nMem+1==pFrame->nChildMem) );
    assert( pProgram->nCsr==pFrame->nChildCsr );
    assert( (int)(pOp - aOp)==pFrame->pc );
  }

  p->nFrame++;

static int vdbeMergeEngineInit(
  SortSubtask *pTask,             /* Thread that will run pMerger */
  MergeEngine *pMerger,           /* MergeEngine to initialize */
  int eMode                       /* One of the INCRINIT_XXX constants */
){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* For looping over PmaReader objects */
  int nTree;                      /* Number of subtrees to merge */

  /* Failure to allocate the merge would have been detected prior to
  ** invoking this routine */
  assert( pMerger!=0 );

  /* eMode is always INCRINIT_NORMAL in single-threaded mode */
  assert( SQLITE_MAX_WORKER_THREADS>0 || eMode==INCRINIT_NORMAL );

  /* Verify that the MergeEngine is assigned to a single thread */
  assert( pMerger->pTask==0 );
  pMerger->pTask = pTask;

  nTree = pMerger->nTree;
  for(i=0; i<nTree; i++){
    if( SQLITE_MAX_WORKER_THREADS>0 && eMode==INCRINIT_ROOT ){
      /* PmaReaders should be normally initialized in order, as if they are
      ** reading from the same temp file this makes for more linear file IO.
      ** However, in the INCRINIT_ROOT case, if PmaReader aReadr[nTask-1] is
      ** in use it will block the vdbePmaReaderNext() call while it uses
      ** the main thread to fill its buffer. So calling PmaReaderNext()

      ** see if it is a column in a virtual table.  This is done because
      ** the left operand of infix functions (the operand we want to
      ** control overloading) ends up as the second argument to the
      ** function.  The expression "A glob B" is equivalent to 
      ** "glob(B,A).  We want to use the A in "A glob B" to test
      ** for function overloading.  But we use the B term in "glob(B,A)".
      */
      if( nFarg>=2 && ExprHasProperty(pExpr, EP_InfixFunc) ){
        pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[1].pExpr);
      }else if( nFarg>0 ){
        pDef = sqlite3VtabOverloadFunction(db, pDef, nFarg, pFarg->a[0].pExpr);
      }
#endif
      if( pDef->funcFlags & SQLITE_FUNC_NEEDCOLL ){
        if( !pColl ) pColl = db->pDfltColl; 

  sqlite3_str_appendall(&acc, "CREATE TABLE x");
  for(i=0, j=pPragma->iPragCName; i<pPragma->nPragCName; i++, j++){
    sqlite3_str_appendf(&acc, "%c\"%s\"", cSep, pragCName[j]);
    cSep = ',';
  }
  if( i==0 ){
    sqlite3_str_appendf(&acc, "(\"%s\"", pPragma->zName);

    i++;
  }
  j = 0;
  if( pPragma->mPragFlg & PragFlg_Result1 ){
    sqlite3_str_appendall(&acc, ",arg HIDDEN");
    j++;
  }

  Table *pTab,          /* The table being updated */
  Index *pIdx,          /* The UNIQUE constraint that failed */
  int iCur              /* Cursor for pIdx (or pTab if pIdx==NULL) */
){
  Vdbe *v = pParse->pVdbe;
  sqlite3 *db = pParse->db;
  SrcList *pSrc;            /* FROM clause for the UPDATE */
  int iDataCur;

  assert( v!=0 );
  assert( pUpsert!=0 );
  VdbeNoopComment((v, "Begin DO UPDATE of UPSERT"));
  iDataCur = pUpsert->iDataCur;
  if( pIdx && iCur!=iDataCur ){
    if( HasRowid(pTab) ){
      int regRowid = sqlite3GetTempReg(pParse);
      sqlite3VdbeAddOp2(v, OP_IdxRowid, iCur, regRowid);
      sqlite3VdbeAddOp3(v, OP_SeekRowid, iDataCur, 0, regRowid);
      VdbeCoverage(v);
      sqlite3ReleaseTempReg(pParse, regRowid);

** appropriate virtual table operator.  The return value is 1 or 2 if there
** is a match.  The usual return is 1, but if the RHS is also a column
** of virtual table in forms (5) or (7) then return 2.
**
** If the expression matches none of the patterns above, return 0.
*/
static int isAuxiliaryVtabOperator(
  sqlite3 *db,                    /* Parsing context */
  Expr *pExpr,                    /* Test this expression */
  unsigned char *peOp2,           /* OUT: 0 for MATCH, or else an op2 value */
  Expr **ppLeft,                  /* Column expression to left of MATCH/op2 */
  Expr **ppRight                  /* Expression to left of MATCH/op2 */
){
  if( pExpr->op==TK_FUNCTION ){
    static const struct Op2 {

    Expr *pCol;                     /* Column reference */
    int i;

    pList = pExpr->x.pList;
    if( pList==0 || pList->nExpr!=2 ){
      return 0;
    }

    /* Built-in operators MATCH, GLOB, LIKE, and REGEXP attach to a
    ** virtual table on their second argument, which is the same as
    ** the left-hand side operand in their in-fix form.
    **
    **       vtab_column MATCH expression
    **       MATCH(expression,vtab_column)
    */
    pCol = pList->a[1].pExpr;
    if( pCol->op==TK_COLUMN && IsVirtual(pCol->pTab) ){


      for(i=0; i<ArraySize(aOp); i++){
        if( sqlite3StrICmp(pExpr->u.zToken, aOp[i].zOp)==0 ){
          *peOp2 = aOp[i].eOp2;
          *ppRight = pList->a[0].pExpr;
          *ppLeft = pCol;
          return 1;
        }
      }
    }

    /* We can also match against the first column of overloaded
    ** functions where xFindFunction returns a value of at least
    ** SQLITE_INDEX_CONSTRAINT_FUNCTION.
    **
    **      OVERLOADED(vtab_column,expression)
    **
    ** Historically, xFindFunction expected to see lower-case function
    ** names.  But for this use case, xFindFunction is expected to deal
    ** with function names in an arbitrary case.
    */
    pCol = pList->a[0].pExpr;
    if( pCol->op==TK_COLUMN && IsVirtual(pCol->pTab) ){
      sqlite3_vtab *pVtab;
      sqlite3_module *pMod;
      void (*xNotUsed)(sqlite3_context*,int,sqlite3_value**);
      void *pNotUsed;
      pVtab = sqlite3GetVTable(db, pCol->pTab)->pVtab;
      assert( pVtab!=0 );
      assert( pVtab->pModule!=0 );
      pMod = (sqlite3_module *)pVtab->pModule;
      if( pMod->xFindFunction!=0 ){
        i = pMod->xFindFunction(pVtab,2, pExpr->u.zToken, &xNotUsed, &pNotUsed);
        if( i>=SQLITE_INDEX_CONSTRAINT_FUNCTION ){
          *peOp2 = i;
          *ppRight = pList->a[1].pExpr;
          *ppLeft = pCol;
          return 1;
        }
      }
    }
  }else if( pExpr->op==TK_NE || pExpr->op==TK_ISNOT || pExpr->op==TK_NOTNULL ){
    int res = 0;
    Expr *pLeft = pExpr->pLeft;
    Expr *pRight = pExpr->pRight;
    if( pLeft->op==TK_COLUMN && IsVirtual(pLeft->pTab) ){

        int idxNew;
        transferJoinMarkings(pNew, pExpr);
        assert( !ExprHasProperty(pNew, EP_xIsSelect) );
        pNew->x.pList = pList;
        idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC);
        testcase( idxNew==0 );
        exprAnalyze(pSrc, pWC, idxNew);
        /* pTerm = &pWC->a[idxTerm]; // would be needed if pTerm where used again */
        markTermAsChild(pWC, idxNew, idxTerm);
      }else{
        sqlite3ExprListDelete(db, pList);
      }
    }
  }
}

  ** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL.
  ** This information is used by the xBestIndex methods of
  ** virtual tables.  The native query optimizer does not attempt
  ** to do anything with MATCH functions.
  */
  if( pWC->op==TK_AND ){
    Expr *pRight = 0, *pLeft = 0;
    int res = isAuxiliaryVtabOperator(db, pExpr, &eOp2, &pLeft, &pRight);
    while( res-- > 0 ){
      int idxNew;
      WhereTerm *pNewTerm;
      Bitmask prereqColumn, prereqExpr;

      prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight);
      prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft);

  return ret;
}
#endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */
#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */

/************** End of fts3_unicode2.c ***************************************/
/************** Begin file json1.c *******************************************/
/*
** 2015-08-12
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements JSON functions.  The interface is
** modeled after MySQL JSON functions:
**
**     https://dev.mysql.com/doc/refman/5.7/en/json.html
**
** For the time being, all JSON is stored as pure text.  (We might add
** a JSONB type in the future which stores a binary encoding of JSON in
** a BLOB, but there is no support for JSONB in the current implementation.
** This implementation parses JSON text at 250 MB/s, so it is hard to see
** how JSONB might improve on that.)
*/
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1)
#if !defined(SQLITEINT_H)
/* #include "sqlite3ext.h" */
#endif
SQLITE_EXTENSION_INIT1
/* #include <assert.h> */
/* #include <string.h> */
/* #include <stdlib.h> */
/* #include <stdarg.h> */

/* Mark a function parameter as unused, to suppress nuisance compiler
** warnings. */
#ifndef UNUSED_PARAM
# define UNUSED_PARAM(X)  (void)(X)
#endif

#ifndef LARGEST_INT64
# define LARGEST_INT64  (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32))
# define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64)
#endif

/*
** Versions of isspace(), isalnum() and isdigit() to which it is safe
** to pass signed char values.
*/
#ifdef sqlite3Isdigit
   /* Use the SQLite core versions if this routine is part of the
   ** SQLite amalgamation */
#  define safe_isdigit(x)  sqlite3Isdigit(x)
#  define safe_isalnum(x)  sqlite3Isalnum(x)
#  define safe_isxdigit(x) sqlite3Isxdigit(x)
#else
   /* Use the standard library for separate compilation */
#include <ctype.h>  /* amalgamator: keep */
#  define safe_isdigit(x)  isdigit((unsigned char)(x))
#  define safe_isalnum(x)  isalnum((unsigned char)(x))
#  define safe_isxdigit(x) isxdigit((unsigned char)(x))
#endif

/*
** Growing our own isspace() routine this way is twice as fast as
** the library isspace() function, resulting in a 7% overall performance
** increase for the parser.  (Ubuntu14.10 gcc 4.8.4 x64 with -Os).
*/
static const char jsonIsSpace[] = {
  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
};
#define safe_isspace(x) (jsonIsSpace[(unsigned char)x])

#ifndef SQLITE_AMALGAMATION
  /* Unsigned integer types.  These are already defined in the sqliteInt.h,
  ** but the definitions need to be repeated for separate compilation. */
  typedef sqlite3_uint64 u64;
  typedef unsigned int u32;
  typedef unsigned short int u16;
  typedef unsigned char u8;
#endif

/* Objects */
typedef struct JsonString JsonString;
typedef struct JsonNode JsonNode;
typedef struct JsonParse JsonParse;

/* An instance of this object represents a JSON string
** under construction.  Really, this is a generic string accumulator
** that can be and is used to create strings other than JSON.
*/
struct JsonString {
  sqlite3_context *pCtx;   /* Function context - put error messages here */
  char *zBuf;              /* Append JSON content here */
  u64 nAlloc;              /* Bytes of storage available in zBuf[] */
  u64 nUsed;               /* Bytes of zBuf[] currently used */
  u8 bStatic;              /* True if zBuf is static space */
  u8 bErr;                 /* True if an error has been encountered */
  char zSpace[100];        /* Initial static space */
};

/* JSON type values
*/
#define JSON_NULL     0
#define JSON_TRUE     1
#define JSON_FALSE    2
#define JSON_INT      3
#define JSON_REAL     4
#define JSON_STRING   5
#define JSON_ARRAY    6
#define JSON_OBJECT   7

/* The "subtype" set for JSON values */
#define JSON_SUBTYPE  74    /* Ascii for "J" */

/*
** Names of the various JSON types:
*/
static const char * const jsonType[] = {
  "null", "true", "false", "integer", "real", "text", "array", "object"
};

/* Bit values for the JsonNode.jnFlag field
*/
#define JNODE_RAW     0x01         /* Content is raw, not JSON encoded */
#define JNODE_ESCAPE  0x02         /* Content is text with \ escapes */
#define JNODE_REMOVE  0x04         /* Do not output */
#define JNODE_REPLACE 0x08         /* Replace with JsonNode.u.iReplace */
#define JNODE_PATCH   0x10         /* Patch with JsonNode.u.pPatch */
#define JNODE_APPEND  0x20         /* More ARRAY/OBJECT entries at u.iAppend */
#define JNODE_LABEL   0x40         /* Is a label of an object */


/* A single node of parsed JSON
*/
struct JsonNode {
  u8 eType;              /* One of the JSON_ type values */
  u8 jnFlags;            /* JNODE flags */
  u32 n;                 /* Bytes of content, or number of sub-nodes */
  union {
    const char *zJContent; /* Content for INT, REAL, and STRING */
    u32 iAppend;           /* More terms for ARRAY and OBJECT */
    u32 iKey;              /* Key for ARRAY objects in json_tree() */
    u32 iReplace;          /* Replacement content for JNODE_REPLACE */
    JsonNode *pPatch;      /* Node chain of patch for JNODE_PATCH */
  } u;
};

/* A completely parsed JSON string
*/
struct JsonParse {
  u32 nNode;         /* Number of slots of aNode[] used */
  u32 nAlloc;        /* Number of slots of aNode[] allocated */
  JsonNode *aNode;   /* Array of nodes containing the parse */
  const char *zJson; /* Original JSON string */
  u32 *aUp;          /* Index of parent of each node */
  u8 oom;            /* Set to true if out of memory */
  u8 nErr;           /* Number of errors seen */
  u16 iDepth;        /* Nesting depth */
  int nJson;         /* Length of the zJson string in bytes */
  u32 iHold;         /* Replace cache line with the lowest iHold value */
};

/*
** Maximum nesting depth of JSON for this implementation.
**
** This limit is needed to avoid a stack overflow in the recursive
** descent parser.  A depth of 2000 is far deeper than any sane JSON
** should go.
*/
#define JSON_MAX_DEPTH  2000

/**************************************************************************
** Utility routines for dealing with JsonString objects
**************************************************************************/

/* Set the JsonString object to an empty string
*/
static void jsonZero(JsonString *p){
  p->zBuf = p->zSpace;
  p->nAlloc = sizeof(p->zSpace);
  p->nUsed = 0;
  p->bStatic = 1;
}

/* Initialize the JsonString object
*/
static void jsonInit(JsonString *p, sqlite3_context *pCtx){
  p->pCtx = pCtx;
  p->bErr = 0;
  jsonZero(p);
}


/* Free all allocated memory and reset the JsonString object back to its
** initial state.
*/
static void jsonReset(JsonString *p){
  if( !p->bStatic ) sqlite3_free(p->zBuf);
  jsonZero(p);
}


/* Report an out-of-memory (OOM) condition 
*/
static void jsonOom(JsonString *p){
  p->bErr = 1;
  sqlite3_result_error_nomem(p->pCtx);
  jsonReset(p);
}

/* Enlarge pJson->zBuf so that it can hold at least N more bytes.
** Return zero on success.  Return non-zero on an OOM error
*/
static int jsonGrow(JsonString *p, u32 N){
  u64 nTotal = N<p->nAlloc ? p->nAlloc*2 : p->nAlloc+N+10;
  char *zNew;
  if( p->bStatic ){
    if( p->bErr ) return 1;
    zNew = sqlite3_malloc64(nTotal);
    if( zNew==0 ){
      jsonOom(p);
      return SQLITE_NOMEM;
    }
    memcpy(zNew, p->zBuf, (size_t)p->nUsed);
    p->zBuf = zNew;
    p->bStatic = 0;
  }else{
    zNew = sqlite3_realloc64(p->zBuf, nTotal);
    if( zNew==0 ){
      jsonOom(p);
      return SQLITE_NOMEM;
    }
    p->zBuf = zNew;
  }
  p->nAlloc = nTotal;
  return SQLITE_OK;
}

/* Append N bytes from zIn onto the end of the JsonString string.
*/
static void jsonAppendRaw(JsonString *p, const char *zIn, u32 N){
  if( (N+p->nUsed >= p->nAlloc) && jsonGrow(p,N)!=0 ) return;
  memcpy(p->zBuf+p->nUsed, zIn, N);
  p->nUsed += N;
}

/* Append formatted text (not to exceed N bytes) to the JsonString.
*/
static void jsonPrintf(int N, JsonString *p, const char *zFormat, ...){
  va_list ap;
  if( (p->nUsed + N >= p->nAlloc) && jsonGrow(p, N) ) return;
  va_start(ap, zFormat);
  sqlite3_vsnprintf(N, p->zBuf+p->nUsed, zFormat, ap);
  va_end(ap);
  p->nUsed += (int)strlen(p->zBuf+p->nUsed);
}

/* Append a single character
*/
static void jsonAppendChar(JsonString *p, char c){
  if( p->nUsed>=p->nAlloc && jsonGrow(p,1)!=0 ) return;
  p->zBuf[p->nUsed++] = c;
}

/* Append a comma separator to the output buffer, if the previous
** character is not '[' or '{'.
*/
static void jsonAppendSeparator(JsonString *p){
  char c;
  if( p->nUsed==0 ) return;
  c = p->zBuf[p->nUsed-1];
  if( c!='[' && c!='{' ) jsonAppendChar(p, ',');
}

/* Append the N-byte string in zIn to the end of the JsonString string
** under construction.  Enclose the string in "..." and escape
** any double-quotes or backslash characters contained within the
** string.
*/
static void jsonAppendString(JsonString *p, const char *zIn, u32 N){
  u32 i;
  if( (N+p->nUsed+2 >= p->nAlloc) && jsonGrow(p,N+2)!=0 ) return;
  p->zBuf[p->nUsed++] = '"';
  for(i=0; i<N; i++){
    unsigned char c = ((unsigned const char*)zIn)[i];
    if( c=='"' || c=='\\' ){
      json_simple_escape:
      if( (p->nUsed+N+3-i > p->nAlloc) && jsonGrow(p,N+3-i)!=0 ) return;
      p->zBuf[p->nUsed++] = '\\';
    }else if( c<=0x1f ){
      static const char aSpecial[] = {
         0, 0, 0, 0, 0, 0, 0, 0, 'b', 't', 'n', 0, 'f', 'r', 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0,   0,   0,   0, 0,   0,   0, 0, 0
      };
      assert( sizeof(aSpecial)==32 );
      assert( aSpecial['\b']=='b' );
      assert( aSpecial['\f']=='f' );
      assert( aSpecial['\n']=='n' );
      assert( aSpecial['\r']=='r' );
      assert( aSpecial['\t']=='t' );
      if( aSpecial[c] ){
        c = aSpecial[c];
        goto json_simple_escape;
      }
      if( (p->nUsed+N+7+i > p->nAlloc) && jsonGrow(p,N+7-i)!=0 ) return;
      p->zBuf[p->nUsed++] = '\\';
      p->zBuf[p->nUsed++] = 'u';
      p->zBuf[p->nUsed++] = '0';
      p->zBuf[p->nUsed++] = '0';
      p->zBuf[p->nUsed++] = '0' + (c>>4);
      c = "0123456789abcdef"[c&0xf];
    }
    p->zBuf[p->nUsed++] = c;
  }
  p->zBuf[p->nUsed++] = '"';
  assert( p->nUsed<p->nAlloc );
}

/*
** Append a function parameter value to the JSON string under 
** construction.
*/
static void jsonAppendValue(
  JsonString *p,                 /* Append to this JSON string */
  sqlite3_value *pValue          /* Value to append */
){
  switch( sqlite3_value_type(pValue) ){
    case SQLITE_NULL: {
      jsonAppendRaw(p, "null", 4);
      break;
    }
    case SQLITE_INTEGER:
    case SQLITE_FLOAT: {
      const char *z = (const char*)sqlite3_value_text(pValue);
      u32 n = (u32)sqlite3_value_bytes(pValue);
      jsonAppendRaw(p, z, n);
      break;
    }
    case SQLITE_TEXT: {
      const char *z = (const char*)sqlite3_value_text(pValue);
      u32 n = (u32)sqlite3_value_bytes(pValue);
      if( sqlite3_value_subtype(pValue)==JSON_SUBTYPE ){
        jsonAppendRaw(p, z, n);
      }else{
        jsonAppendString(p, z, n);
      }
      break;
    }
    default: {
      if( p->bErr==0 ){
        sqlite3_result_error(p->pCtx, "JSON cannot hold BLOB values", -1);
        p->bErr = 2;
        jsonReset(p);
      }
      break;
    }
  }
}


/* Make the JSON in p the result of the SQL function.
*/
static void jsonResult(JsonString *p){
  if( p->bErr==0 ){
    sqlite3_result_text64(p->pCtx, p->zBuf, p->nUsed, 
                          p->bStatic ? SQLITE_TRANSIENT : sqlite3_free,
                          SQLITE_UTF8);
    jsonZero(p);
  }
  assert( p->bStatic );
}

/**************************************************************************
** Utility routines for dealing with JsonNode and JsonParse objects
**************************************************************************/

/*
** Return the number of consecutive JsonNode slots need to represent
** the parsed JSON at pNode.  The minimum answer is 1.  For ARRAY and
** OBJECT types, the number might be larger.
**
** Appended elements are not counted.  The value returned is the number
** by which the JsonNode counter should increment in order to go to the
** next peer value.
*/
static u32 jsonNodeSize(JsonNode *pNode){
  return pNode->eType>=JSON_ARRAY ? pNode->n+1 : 1;
}

/*
** Reclaim all memory allocated by a JsonParse object.  But do not
** delete the JsonParse object itself.
*/
static void jsonParseReset(JsonParse *pParse){
  sqlite3_free(pParse->aNode);
  pParse->aNode = 0;
  pParse->nNode = 0;
  pParse->nAlloc = 0;
  sqlite3_free(pParse->aUp);
  pParse->aUp = 0;
}

/*
** Free a JsonParse object that was obtained from sqlite3_malloc().
*/
static void jsonParseFree(JsonParse *pParse){
  jsonParseReset(pParse);
  sqlite3_free(pParse);
}

/*
** Convert the JsonNode pNode into a pure JSON string and
** append to pOut.  Subsubstructure is also included.  Return
** the number of JsonNode objects that are encoded.
*/
static void jsonRenderNode(
  JsonNode *pNode,               /* The node to render */
  JsonString *pOut,              /* Write JSON here */
  sqlite3_value **aReplace       /* Replacement values */
){
  if( pNode->jnFlags & (JNODE_REPLACE|JNODE_PATCH) ){
    if( pNode->jnFlags & JNODE_REPLACE ){
      jsonAppendValue(pOut, aReplace[pNode->u.iReplace]);
      return;
    }
    pNode = pNode->u.pPatch;
  }
  switch( pNode->eType ){
    default: {
      assert( pNode->eType==JSON_NULL );
      jsonAppendRaw(pOut, "null", 4);
      break;
    }
    case JSON_TRUE: {
      jsonAppendRaw(pOut, "true", 4);
      break;
    }
    case JSON_FALSE: {
      jsonAppendRaw(pOut, "false", 5);
      break;
    }
    case JSON_STRING: {
      if( pNode->jnFlags & JNODE_RAW ){
        jsonAppendString(pOut, pNode->u.zJContent, pNode->n);
        break;
      }
      /* Fall through into the next case */
    }
    case JSON_REAL:
    case JSON_INT: {
      jsonAppendRaw(pOut, pNode->u.zJContent, pNode->n);
      break;
    }
    case JSON_ARRAY: {
      u32 j = 1;
      jsonAppendChar(pOut, '[');
      for(;;){
        while( j<=pNode->n ){
          if( (pNode[j].jnFlags & JNODE_REMOVE)==0 ){
            jsonAppendSeparator(pOut);
            jsonRenderNode(&pNode[j], pOut, aReplace);
          }
          j += jsonNodeSize(&pNode[j]);
        }
        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
        pNode = &pNode[pNode->u.iAppend];
        j = 1;
      }
      jsonAppendChar(pOut, ']');
      break;
    }
    case JSON_OBJECT: {
      u32 j = 1;
      jsonAppendChar(pOut, '{');
      for(;;){
        while( j<=pNode->n ){
          if( (pNode[j+1].jnFlags & JNODE_REMOVE)==0 ){
            jsonAppendSeparator(pOut);
            jsonRenderNode(&pNode[j], pOut, aReplace);
            jsonAppendChar(pOut, ':');
            jsonRenderNode(&pNode[j+1], pOut, aReplace);
          }
          j += 1 + jsonNodeSize(&pNode[j+1]);
        }
        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
        pNode = &pNode[pNode->u.iAppend];
        j = 1;
      }
      jsonAppendChar(pOut, '}');
      break;
    }
  }
}

/*
** Return a JsonNode and all its descendents as a JSON string.
*/
static void jsonReturnJson(
  JsonNode *pNode,            /* Node to return */
  sqlite3_context *pCtx,      /* Return value for this function */
  sqlite3_value **aReplace    /* Array of replacement values */
){
  JsonString s;
  jsonInit(&s, pCtx);
  jsonRenderNode(pNode, &s, aReplace);
  jsonResult(&s);
  sqlite3_result_subtype(pCtx, JSON_SUBTYPE);
}

/*
** Make the JsonNode the return value of the function.
*/
static void jsonReturn(
  JsonNode *pNode,            /* Node to return */
  sqlite3_context *pCtx,      /* Return value for this function */
  sqlite3_value **aReplace    /* Array of replacement values */
){
  switch( pNode->eType ){
    default: {
      assert( pNode->eType==JSON_NULL );
      sqlite3_result_null(pCtx);
      break;
    }
    case JSON_TRUE: {
      sqlite3_result_int(pCtx, 1);
      break;
    }
    case JSON_FALSE: {
      sqlite3_result_int(pCtx, 0);
      break;
    }
    case JSON_INT: {
      sqlite3_int64 i = 0;
      const char *z = pNode->u.zJContent;
      if( z[0]=='-' ){ z++; }
      while( z[0]>='0' && z[0]<='9' ){
        unsigned v = *(z++) - '0';
        if( i>=LARGEST_INT64/10 ){
          if( i>LARGEST_INT64/10 ) goto int_as_real;
          if( z[0]>='0' && z[0]<='9' ) goto int_as_real;
          if( v==9 ) goto int_as_real;
          if( v==8 ){
            if( pNode->u.zJContent[0]=='-' ){
              sqlite3_result_int64(pCtx, SMALLEST_INT64);
              goto int_done;
            }else{
              goto int_as_real;
            }
          }
        }
        i = i*10 + v;
      }
      if( pNode->u.zJContent[0]=='-' ){ i = -i; }
      sqlite3_result_int64(pCtx, i);
      int_done:
      break;
      int_as_real: /* fall through to real */;
    }
    case JSON_REAL: {
      double r;
#ifdef SQLITE_AMALGAMATION
      const char *z = pNode->u.zJContent;
      sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);
#else
      r = strtod(pNode->u.zJContent, 0);
#endif
      sqlite3_result_double(pCtx, r);
      break;
    }
    case JSON_STRING: {
#if 0 /* Never happens because JNODE_RAW is only set by json_set(),
      ** json_insert() and json_replace() and those routines do not
      ** call jsonReturn() */
      if( pNode->jnFlags & JNODE_RAW ){
        sqlite3_result_text(pCtx, pNode->u.zJContent, pNode->n,
                            SQLITE_TRANSIENT);
      }else 
#endif
      assert( (pNode->jnFlags & JNODE_RAW)==0 );
      if( (pNode->jnFlags & JNODE_ESCAPE)==0 ){
        /* JSON formatted without any backslash-escapes */
        sqlite3_result_text(pCtx, pNode->u.zJContent+1, pNode->n-2,
                            SQLITE_TRANSIENT);
      }else{
        /* Translate JSON formatted string into raw text */
        u32 i;
        u32 n = pNode->n;
        const char *z = pNode->u.zJContent;
        char *zOut;
        u32 j;
        zOut = sqlite3_malloc( n+1 );
        if( zOut==0 ){
          sqlite3_result_error_nomem(pCtx);
          break;
        }
        for(i=1, j=0; i<n-1; i++){
          char c = z[i];
          if( c!='\\' ){
            zOut[j++] = c;
          }else{
            c = z[++i];
            if( c=='u' ){
              u32 v = 0, k;
              for(k=0; k<4; i++, k++){
                assert( i<n-2 );
                c = z[i+1];
                assert( safe_isxdigit(c) );
                if( c<='9' ) v = v*16 + c - '0';
                else if( c<='F' ) v = v*16 + c - 'A' + 10;
                else v = v*16 + c - 'a' + 10;
              }
              if( v==0 ) break;
              if( v<=0x7f ){
                zOut[j++] = (char)v;
              }else if( v<=0x7ff ){
                zOut[j++] = (char)(0xc0 | (v>>6));
                zOut[j++] = 0x80 | (v&0x3f);
              }else{
                zOut[j++] = (char)(0xe0 | (v>>12));
                zOut[j++] = 0x80 | ((v>>6)&0x3f);
                zOut[j++] = 0x80 | (v&0x3f);
              }
            }else{
              if( c=='b' ){
                c = '\b';
              }else if( c=='f' ){
                c = '\f';
              }else if( c=='n' ){
                c = '\n';
              }else if( c=='r' ){
                c = '\r';
              }else if( c=='t' ){
                c = '\t';
              }
              zOut[j++] = c;
            }
          }
        }
        zOut[j] = 0;
        sqlite3_result_text(pCtx, zOut, j, sqlite3_free);
      }
      break;
    }
    case JSON_ARRAY:
    case JSON_OBJECT: {
      jsonReturnJson(pNode, pCtx, aReplace);
      break;
    }
  }
}

/* Forward reference */
static int jsonParseAddNode(JsonParse*,u32,u32,const char*);

/*
** A macro to hint to the compiler that a function should not be
** inlined.
*/
#if defined(__GNUC__)
#  define JSON_NOINLINE  __attribute__((noinline))
#elif defined(_MSC_VER) && _MSC_VER>=1310
#  define JSON_NOINLINE  __declspec(noinline)
#else
#  define JSON_NOINLINE
#endif


static JSON_NOINLINE int jsonParseAddNodeExpand(
  JsonParse *pParse,        /* Append the node to this object */
  u32 eType,                /* Node type */
  u32 n,                    /* Content size or sub-node count */
  const char *zContent      /* Content */
){
  u32 nNew;
  JsonNode *pNew;
  assert( pParse->nNode>=pParse->nAlloc );
  if( pParse->oom ) return -1;
  nNew = pParse->nAlloc*2 + 10;
  pNew = sqlite3_realloc(pParse->aNode, sizeof(JsonNode)*nNew);
  if( pNew==0 ){
    pParse->oom = 1;
    return -1;
  }
  pParse->nAlloc = nNew;
  pParse->aNode = pNew;
  assert( pParse->nNode<pParse->nAlloc );
  return jsonParseAddNode(pParse, eType, n, zContent);
}

/*
** Create a new JsonNode instance based on the arguments and append that
** instance to the JsonParse.  Return the index in pParse->aNode[] of the
** new node, or -1 if a memory allocation fails.
*/
static int jsonParseAddNode(
  JsonParse *pParse,        /* Append the node to this object */
  u32 eType,                /* Node type */
  u32 n,                    /* Content size or sub-node count */
  const char *zContent      /* Content */
){
  JsonNode *p;
  if( pParse->nNode>=pParse->nAlloc ){
    return jsonParseAddNodeExpand(pParse, eType, n, zContent);
  }
  p = &pParse->aNode[pParse->nNode];
  p->eType = (u8)eType;
  p->jnFlags = 0;
  p->n = n;
  p->u.zJContent = zContent;
  return pParse->nNode++;
}

/*
** Return true if z[] begins with 4 (or more) hexadecimal digits
*/
static int jsonIs4Hex(const char *z){
  int i;
  for(i=0; i<4; i++) if( !safe_isxdigit(z[i]) ) return 0;
  return 1;
}

/*
** Parse a single JSON value which begins at pParse->zJson[i].  Return the
** index of the first character past the end of the value parsed.
**
** Return negative for a syntax error.  Special cases:  return -2 if the
** first non-whitespace character is '}' and return -3 if the first
** non-whitespace character is ']'.
*/
static int jsonParseValue(JsonParse *pParse, u32 i){
  char c;
  u32 j;
  int iThis;
  int x;
  JsonNode *pNode;
  const char *z = pParse->zJson;
  while( safe_isspace(z[i]) ){ i++; }
  if( (c = z[i])=='{' ){
    /* Parse object */
    iThis = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
    if( iThis<0 ) return -1;
    for(j=i+1;;j++){
      while( safe_isspace(z[j]) ){ j++; }
      if( ++pParse->iDepth > JSON_MAX_DEPTH ) return -1;
      x = jsonParseValue(pParse, j);
      if( x<0 ){
        pParse->iDepth--;
        if( x==(-2) && pParse->nNode==(u32)iThis+1 ) return j+1;
        return -1;
      }
      if( pParse->oom ) return -1;
      pNode = &pParse->aNode[pParse->nNode-1];
      if( pNode->eType!=JSON_STRING ) return -1;
      pNode->jnFlags |= JNODE_LABEL;
      j = x;
      while( safe_isspace(z[j]) ){ j++; }
      if( z[j]!=':' ) return -1;
      j++;
      x = jsonParseValue(pParse, j);
      pParse->iDepth--;
      if( x<0 ) return -1;
      j = x;
      while( safe_isspace(z[j]) ){ j++; }
      c = z[j];
      if( c==',' ) continue;
      if( c!='}' ) return -1;
      break;
    }
    pParse->aNode[iThis].n = pParse->nNode - (u32)iThis - 1;
    return j+1;
  }else if( c=='[' ){
    /* Parse array */
    iThis = jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);
    if( iThis<0 ) return -1;
    for(j=i+1;;j++){
      while( safe_isspace(z[j]) ){ j++; }
      if( ++pParse->iDepth > JSON_MAX_DEPTH ) return -1;
      x = jsonParseValue(pParse, j);
      pParse->iDepth--;
      if( x<0 ){
        if( x==(-3) && pParse->nNode==(u32)iThis+1 ) return j+1;
        return -1;
      }
      j = x;
      while( safe_isspace(z[j]) ){ j++; }
      c = z[j];
      if( c==',' ) continue;
      if( c!=']' ) return -1;
      break;
    }
    pParse->aNode[iThis].n = pParse->nNode - (u32)iThis - 1;
    return j+1;
  }else if( c=='"' ){
    /* Parse string */
    u8 jnFlags = 0;
    j = i+1;
    for(;;){
      c = z[j];
      if( (c & ~0x1f)==0 ){
        /* Control characters are not allowed in strings */
        return -1;
      }
      if( c=='\\' ){
        c = z[++j];
        if( c=='"' || c=='\\' || c=='/' || c=='b' || c=='f'
           || c=='n' || c=='r' || c=='t'
           || (c=='u' && jsonIs4Hex(z+j+1)) ){
          jnFlags = JNODE_ESCAPE;
        }else{
          return -1;
        }
      }else if( c=='"' ){
        break;
      }
      j++;
    }
    jsonParseAddNode(pParse, JSON_STRING, j+1-i, &z[i]);
    if( !pParse->oom ) pParse->aNode[pParse->nNode-1].jnFlags = jnFlags;
    return j+1;
  }else if( c=='n'
         && strncmp(z+i,"null",4)==0
         && !safe_isalnum(z[i+4]) ){
    jsonParseAddNode(pParse, JSON_NULL, 0, 0);
    return i+4;
  }else if( c=='t'
         && strncmp(z+i,"true",4)==0
         && !safe_isalnum(z[i+4]) ){
    jsonParseAddNode(pParse, JSON_TRUE, 0, 0);
    return i+4;
  }else if( c=='f'
         && strncmp(z+i,"false",5)==0
         && !safe_isalnum(z[i+5]) ){
    jsonParseAddNode(pParse, JSON_FALSE, 0, 0);
    return i+5;
  }else if( c=='-' || (c>='0' && c<='9') ){
    /* Parse number */
    u8 seenDP = 0;
    u8 seenE = 0;
    assert( '-' < '0' );
    if( c<='0' ){
      j = c=='-' ? i+1 : i;
      if( z[j]=='0' && z[j+1]>='0' && z[j+1]<='9' ) return -1;
    }
    j = i+1;
    for(;; j++){
      c = z[j];
      if( c>='0' && c<='9' ) continue;
      if( c=='.' ){
        if( z[j-1]=='-' ) return -1;
        if( seenDP ) return -1;
        seenDP = 1;
        continue;
      }
      if( c=='e' || c=='E' ){
        if( z[j-1]<'0' ) return -1;
        if( seenE ) return -1;
        seenDP = seenE = 1;
        c = z[j+1];
        if( c=='+' || c=='-' ){
          j++;
          c = z[j+1];
        }
        if( c<'0' || c>'9' ) return -1;
        continue;
      }
      break;
    }
    if( z[j-1]<'0' ) return -1;
    jsonParseAddNode(pParse, seenDP ? JSON_REAL : JSON_INT,
                        j - i, &z[i]);
    return j;
  }else if( c=='}' ){
    return -2;  /* End of {...} */
  }else if( c==']' ){
    return -3;  /* End of [...] */
  }else if( c==0 ){
    return 0;   /* End of file */
  }else{
    return -1;  /* Syntax error */
  }
}

/*
** Parse a complete JSON string.  Return 0 on success or non-zero if there
** are any errors.  If an error occurs, free all memory associated with
** pParse.
**
** pParse is uninitialized when this routine is called.
*/
static int jsonParse(
  JsonParse *pParse,           /* Initialize and fill this JsonParse object */
  sqlite3_context *pCtx,       /* Report errors here */
  const char *zJson            /* Input JSON text to be parsed */
){
  int i;
  memset(pParse, 0, sizeof(*pParse));
  if( zJson==0 ) return 1;
  pParse->zJson = zJson;
  i = jsonParseValue(pParse, 0);
  if( pParse->oom ) i = -1;
  if( i>0 ){
    assert( pParse->iDepth==0 );
    while( safe_isspace(zJson[i]) ) i++;
    if( zJson[i] ) i = -1;
  }
  if( i<=0 ){
    if( pCtx!=0 ){
      if( pParse->oom ){
        sqlite3_result_error_nomem(pCtx);
      }else{
        sqlite3_result_error(pCtx, "malformed JSON", -1);
      }
    }
    jsonParseReset(pParse);
    return 1;
  }
  return 0;
}

/* Mark node i of pParse as being a child of iParent.  Call recursively
** to fill in all the descendants of node i.
*/
static void jsonParseFillInParentage(JsonParse *pParse, u32 i, u32 iParent){
  JsonNode *pNode = &pParse->aNode[i];
  u32 j;
  pParse->aUp[i] = iParent;
  switch( pNode->eType ){
    case JSON_ARRAY: {
      for(j=1; j<=pNode->n; j += jsonNodeSize(pNode+j)){
        jsonParseFillInParentage(pParse, i+j, i);
      }
      break;
    }
    case JSON_OBJECT: {
      for(j=1; j<=pNode->n; j += jsonNodeSize(pNode+j+1)+1){
        pParse->aUp[i+j] = i;
        jsonParseFillInParentage(pParse, i+j+1, i);
      }
      break;
    }
    default: {
      break;
    }
  }
}

/*
** Compute the parentage of all nodes in a completed parse.
*/
static int jsonParseFindParents(JsonParse *pParse){
  u32 *aUp;
  assert( pParse->aUp==0 );
  aUp = pParse->aUp = sqlite3_malloc( sizeof(u32)*pParse->nNode );
  if( aUp==0 ){
    pParse->oom = 1;
    return SQLITE_NOMEM;
  }
  jsonParseFillInParentage(pParse, 0, 0);
  return SQLITE_OK;
}

/*
** Magic number used for the JSON parse cache in sqlite3_get_auxdata()
*/
#define JSON_CACHE_ID  (-429938)  /* First cache entry */
#define JSON_CACHE_SZ  4          /* Max number of cache entries */

/*
** Obtain a complete parse of the JSON found in the first argument
** of the argv array.  Use the sqlite3_get_auxdata() cache for this
** parse if it is available.  If the cache is not available or if it
** is no longer valid, parse the JSON again and return the new parse,
** and also register the new parse so that it will be available for
** future sqlite3_get_auxdata() calls.
*/
static JsonParse *jsonParseCached(
  sqlite3_context *pCtx,
  sqlite3_value **argv,
  sqlite3_context *pErrCtx
){
  const char *zJson = (const char*)sqlite3_value_text(argv[0]);
  int nJson = sqlite3_value_bytes(argv[0]);
  JsonParse *p;
  JsonParse *pMatch = 0;
  int iKey;
  int iMinKey = 0;
  u32 iMinHold = 0xffffffff;
  u32 iMaxHold = 0;
  if( zJson==0 ) return 0;
  for(iKey=0; iKey<JSON_CACHE_SZ; iKey++){
    p = (JsonParse*)sqlite3_get_auxdata(pCtx, JSON_CACHE_ID+iKey);
    if( p==0 ){
      iMinKey = iKey;
      break;
    }
    if( pMatch==0
     && p->nJson==nJson
     && memcmp(p->zJson,zJson,nJson)==0
    ){
      p->nErr = 0;
      pMatch = p;
    }else if( p->iHold<iMinHold ){
      iMinHold = p->iHold;
      iMinKey = iKey;
    }
    if( p->iHold>iMaxHold ){
      iMaxHold = p->iHold;
    }
  }
  if( pMatch ){
    pMatch->nErr = 0;
    pMatch->iHold = iMaxHold+1;
    return pMatch;
  }
  p = sqlite3_malloc( sizeof(*p) + nJson + 1 );
  if( p==0 ){
    sqlite3_result_error_nomem(pCtx);
    return 0;
  }
  memset(p, 0, sizeof(*p));
  p->zJson = (char*)&p[1];
  memcpy((char*)p->zJson, zJson, nJson+1);
  if( jsonParse(p, pErrCtx, p->zJson) ){
    sqlite3_free(p);
    return 0;
  }
  p->nJson = nJson;
  p->iHold = iMaxHold+1;
  sqlite3_set_auxdata(pCtx, JSON_CACHE_ID+iMinKey, p,
                      (void(*)(void*))jsonParseFree);
  return (JsonParse*)sqlite3_get_auxdata(pCtx, JSON_CACHE_ID+iMinKey);
}

/*
** Compare the OBJECT label at pNode against zKey,nKey.  Return true on
** a match.
*/
static int jsonLabelCompare(JsonNode *pNode, const char *zKey, u32 nKey){
  if( pNode->jnFlags & JNODE_RAW ){
    if( pNode->n!=nKey ) return 0;
    return strncmp(pNode->u.zJContent, zKey, nKey)==0;
  }else{
    if( pNode->n!=nKey+2 ) return 0;
    return strncmp(pNode->u.zJContent+1, zKey, nKey)==0;
  }
}

/* forward declaration */
static JsonNode *jsonLookupAppend(JsonParse*,const char*,int*,const char**);

/*
** Search along zPath to find the node specified.  Return a pointer
** to that node, or NULL if zPath is malformed or if there is no such
** node.
**
** If pApnd!=0, then try to append new nodes to complete zPath if it is
** possible to do so and if no existing node corresponds to zPath.  If
** new nodes are appended *pApnd is set to 1.
*/
static JsonNode *jsonLookupStep(
  JsonParse *pParse,      /* The JSON to search */
  u32 iRoot,              /* Begin the search at this node */
  const char *zPath,      /* The path to search */
  int *pApnd,             /* Append nodes to complete path if not NULL */
  const char **pzErr      /* Make *pzErr point to any syntax error in zPath */
){
  u32 i, j, nKey;
  const char *zKey;
  JsonNode *pRoot = &pParse->aNode[iRoot];
  if( zPath[0]==0 ) return pRoot;
  if( zPath[0]=='.' ){
    if( pRoot->eType!=JSON_OBJECT ) return 0;
    zPath++;
    if( zPath[0]=='"' ){
      zKey = zPath + 1;
      for(i=1; zPath[i] && zPath[i]!='"'; i++){}
      nKey = i-1;
      if( zPath[i] ){
        i++;
      }else{
        *pzErr = zPath;
        return 0;
      }
    }else{
      zKey = zPath;
      for(i=0; zPath[i] && zPath[i]!='.' && zPath[i]!='['; i++){}
      nKey = i;
    }
    if( nKey==0 ){
      *pzErr = zPath;
      return 0;
    }
    j = 1;
    for(;;){
      while( j<=pRoot->n ){
        if( jsonLabelCompare(pRoot+j, zKey, nKey) ){
          return jsonLookupStep(pParse, iRoot+j+1, &zPath[i], pApnd, pzErr);
        }
        j++;
        j += jsonNodeSize(&pRoot[j]);
      }
      if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;
      iRoot += pRoot->u.iAppend;
      pRoot = &pParse->aNode[iRoot];
      j = 1;
    }
    if( pApnd ){
      u32 iStart, iLabel;
      JsonNode *pNode;
      iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);
      iLabel = jsonParseAddNode(pParse, JSON_STRING, i, zPath);
      zPath += i;
      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
      if( pParse->oom ) return 0;
      if( pNode ){
        pRoot = &pParse->aNode[iRoot];
        pRoot->u.iAppend = iStart - iRoot;
        pRoot->jnFlags |= JNODE_APPEND;
        pParse->aNode[iLabel].jnFlags |= JNODE_RAW;
      }
      return pNode;
    }
  }else if( zPath[0]=='[' && safe_isdigit(zPath[1]) ){
    if( pRoot->eType!=JSON_ARRAY ) return 0;
    i = 0;
    j = 1;
    while( safe_isdigit(zPath[j]) ){
      i = i*10 + zPath[j] - '0';
      j++;
    }
    if( zPath[j]!=']' ){
      *pzErr = zPath;
      return 0;
    }
    zPath += j + 1;
    j = 1;
    for(;;){
      while( j<=pRoot->n && (i>0 || (pRoot[j].jnFlags & JNODE_REMOVE)!=0) ){
        if( (pRoot[j].jnFlags & JNODE_REMOVE)==0 ) i--;
        j += jsonNodeSize(&pRoot[j]);
      }
      if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;
      iRoot += pRoot->u.iAppend;
      pRoot = &pParse->aNode[iRoot];
      j = 1;
    }
    if( j<=pRoot->n ){
      return jsonLookupStep(pParse, iRoot+j, zPath, pApnd, pzErr);
    }
    if( i==0 && pApnd ){
      u32 iStart;
      JsonNode *pNode;
      iStart = jsonParseAddNode(pParse, JSON_ARRAY, 1, 0);
      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
      if( pParse->oom ) return 0;
      if( pNode ){
        pRoot = &pParse->aNode[iRoot];
        pRoot->u.iAppend = iStart - iRoot;
        pRoot->jnFlags |= JNODE_APPEND;
      }
      return pNode;
    }
  }else{
    *pzErr = zPath;
  }
  return 0;
}

/*
** Append content to pParse that will complete zPath.  Return a pointer
** to the inserted node, or return NULL if the append fails.
*/
static JsonNode *jsonLookupAppend(
  JsonParse *pParse,     /* Append content to the JSON parse */
  const char *zPath,     /* Description of content to append */
  int *pApnd,            /* Set this flag to 1 */
  const char **pzErr     /* Make this point to any syntax error */
){
  *pApnd = 1;
  if( zPath[0]==0 ){
    jsonParseAddNode(pParse, JSON_NULL, 0, 0);
    return pParse->oom ? 0 : &pParse->aNode[pParse->nNode-1];
  }
  if( zPath[0]=='.' ){
    jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
  }else if( strncmp(zPath,"[0]",3)==0 ){
    jsonParseAddNode(pParse, JSON_ARRAY, 0, 0);
  }else{
    return 0;
  }
  if( pParse->oom ) return 0;
  return jsonLookupStep(pParse, pParse->nNode-1, zPath, pApnd, pzErr);
}

/*
** Return the text of a syntax error message on a JSON path.  Space is
** obtained from sqlite3_malloc().
*/
static char *jsonPathSyntaxError(const char *zErr){
  return sqlite3_mprintf("JSON path error near '%q'", zErr);
}

/*
** Do a node lookup using zPath.  Return a pointer to the node on success.
** Return NULL if not found or if there is an error.
**
** On an error, write an error message into pCtx and increment the
** pParse->nErr counter.
**
** If pApnd!=NULL then try to append missing nodes and set *pApnd = 1 if
** nodes are appended.
*/
static JsonNode *jsonLookup(
  JsonParse *pParse,      /* The JSON to search */
  const char *zPath,      /* The path to search */
  int *pApnd,             /* Append nodes to complete path if not NULL */
  sqlite3_context *pCtx   /* Report errors here, if not NULL */
){
  const char *zErr = 0;
  JsonNode *pNode = 0;
  char *zMsg;

  if( zPath==0 ) return 0;
  if( zPath[0]!='$' ){
    zErr = zPath;
    goto lookup_err;
  }
  zPath++;
  pNode = jsonLookupStep(pParse, 0, zPath, pApnd, &zErr);
  if( zErr==0 ) return pNode;

lookup_err:
  pParse->nErr++;
  assert( zErr!=0 && pCtx!=0 );
  zMsg = jsonPathSyntaxError(zErr);
  if( zMsg ){
    sqlite3_result_error(pCtx, zMsg, -1);
    sqlite3_free(zMsg);
  }else{
    sqlite3_result_error_nomem(pCtx);
  }
  return 0;
}


/*
** Report the wrong number of arguments for json_insert(), json_replace()
** or json_set().
*/
static void jsonWrongNumArgs(
  sqlite3_context *pCtx,
  const char *zFuncName
){
  char *zMsg = sqlite3_mprintf("json_%s() needs an odd number of arguments",
                               zFuncName);
  sqlite3_result_error(pCtx, zMsg, -1);
  sqlite3_free(zMsg);     
}

/*
** Mark all NULL entries in the Object passed in as JNODE_REMOVE.
*/
static void jsonRemoveAllNulls(JsonNode *pNode){
  int i, n;
  assert( pNode->eType==JSON_OBJECT );
  n = pNode->n;
  for(i=2; i<=n; i += jsonNodeSize(&pNode[i])+1){
    switch( pNode[i].eType ){
      case JSON_NULL:
        pNode[i].jnFlags |= JNODE_REMOVE;
        break;
      case JSON_OBJECT:
        jsonRemoveAllNulls(&pNode[i]);
        break;
    }
  }
}


/****************************************************************************
** SQL functions used for testing and debugging
****************************************************************************/

#ifdef SQLITE_DEBUG
/*
** The json_parse(JSON) function returns a string which describes
** a parse of the JSON provided.  Or it returns NULL if JSON is not
** well-formed.
*/
static void jsonParseFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonString s;       /* Output string - not real JSON */
  JsonParse x;        /* The parse */
  u32 i;

  assert( argc==1 );
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  jsonParseFindParents(&x);
  jsonInit(&s, ctx);
  for(i=0; i<x.nNode; i++){
    const char *zType;
    if( x.aNode[i].jnFlags & JNODE_LABEL ){
      assert( x.aNode[i].eType==JSON_STRING );
      zType = "label";
    }else{
      zType = jsonType[x.aNode[i].eType];
    }
    jsonPrintf(100, &s,"node %3u: %7s n=%-4d up=%-4d",
               i, zType, x.aNode[i].n, x.aUp[i]);
    if( x.aNode[i].u.zJContent!=0 ){
      jsonAppendRaw(&s, " ", 1);
      jsonAppendRaw(&s, x.aNode[i].u.zJContent, x.aNode[i].n);
    }
    jsonAppendRaw(&s, "\n", 1);
  }
  jsonParseReset(&x);
  jsonResult(&s);
}

/*
** The json_test1(JSON) function return true (1) if the input is JSON
** text generated by another json function.  It returns (0) if the input
** is not known to be JSON.
*/
static void jsonTest1Func(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  UNUSED_PARAM(argc);
  sqlite3_result_int(ctx, sqlite3_value_subtype(argv[0])==JSON_SUBTYPE);
}
#endif /* SQLITE_DEBUG */

/****************************************************************************
** Scalar SQL function implementations
****************************************************************************/

/*
** Implementation of the json_QUOTE(VALUE) function.  Return a JSON value
** corresponding to the SQL value input.  Mostly this means putting 
** double-quotes around strings and returning the unquoted string "null"
** when given a NULL input.
*/
static void jsonQuoteFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonString jx;
  UNUSED_PARAM(argc);

  jsonInit(&jx, ctx);
  jsonAppendValue(&jx, argv[0]);
  jsonResult(&jx);
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}

/*
** Implementation of the json_array(VALUE,...) function.  Return a JSON
** array that contains all values given in arguments.  Or if any argument
** is a BLOB, throw an error.
*/
static void jsonArrayFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  int i;
  JsonString jx;

  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '[');
  for(i=0; i<argc; i++){
    jsonAppendSeparator(&jx);
    jsonAppendValue(&jx, argv[i]);
  }
  jsonAppendChar(&jx, ']');
  jsonResult(&jx);
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}


/*
** json_array_length(JSON)
** json_array_length(JSON, PATH)
**
** Return the number of elements in the top-level JSON array.  
** Return 0 if the input is not a well-formed JSON array.
*/
static void jsonArrayLengthFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  sqlite3_int64 n = 0;
  u32 i;
  JsonNode *pNode;

  p = jsonParseCached(ctx, argv, ctx);
  if( p==0 ) return;
  assert( p->nNode );
  if( argc==2 ){
    const char *zPath = (const char*)sqlite3_value_text(argv[1]);
    pNode = jsonLookup(p, zPath, 0, ctx);
  }else{
    pNode = p->aNode;
  }
  if( pNode==0 ){
    return;
  }
  if( pNode->eType==JSON_ARRAY ){
    assert( (pNode->jnFlags & JNODE_APPEND)==0 );
    for(i=1; i<=pNode->n; n++){
      i += jsonNodeSize(&pNode[i]);
    }
  }
  sqlite3_result_int64(ctx, n);
}

/*
** json_extract(JSON, PATH, ...)
**
** Return the element described by PATH.  Return NULL if there is no
** PATH element.  If there are multiple PATHs, then return a JSON array
** with the result from each path.  Throw an error if the JSON or any PATH
** is malformed.
*/
static void jsonExtractFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  JsonString jx;
  int i;

  if( argc<2 ) return;
  p = jsonParseCached(ctx, argv, ctx);
  if( p==0 ) return;
  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '[');
  for(i=1; i<argc; i++){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    pNode = jsonLookup(p, zPath, 0, ctx);
    if( p->nErr ) break;
    if( argc>2 ){
      jsonAppendSeparator(&jx);
      if( pNode ){
        jsonRenderNode(pNode, &jx, 0);
      }else{
        jsonAppendRaw(&jx, "null", 4);
      }
    }else if( pNode ){
      jsonReturn(pNode, ctx, 0);
    }
  }
  if( argc>2 && i==argc ){
    jsonAppendChar(&jx, ']');
    jsonResult(&jx);
    sqlite3_result_subtype(ctx, JSON_SUBTYPE);
  }
  jsonReset(&jx);
}

/* This is the RFC 7396 MergePatch algorithm.
*/
static JsonNode *jsonMergePatch(
  JsonParse *pParse,   /* The JSON parser that contains the TARGET */
  u32 iTarget,         /* Node of the TARGET in pParse */
  JsonNode *pPatch     /* The PATCH */
){
  u32 i, j;
  u32 iRoot;
  JsonNode *pTarget;
  if( pPatch->eType!=JSON_OBJECT ){
    return pPatch;
  }
  assert( iTarget>=0 && iTarget<pParse->nNode );
  pTarget = &pParse->aNode[iTarget];
  assert( (pPatch->jnFlags & JNODE_APPEND)==0 );
  if( pTarget->eType!=JSON_OBJECT ){
    jsonRemoveAllNulls(pPatch);
    return pPatch;
  }
  iRoot = iTarget;
  for(i=1; i<pPatch->n; i += jsonNodeSize(&pPatch[i+1])+1){
    u32 nKey;
    const char *zKey;
    assert( pPatch[i].eType==JSON_STRING );
    assert( pPatch[i].jnFlags & JNODE_LABEL );
    nKey = pPatch[i].n;
    zKey = pPatch[i].u.zJContent;
    assert( (pPatch[i].jnFlags & JNODE_RAW)==0 );
    for(j=1; j<pTarget->n; j += jsonNodeSize(&pTarget[j+1])+1 ){
      assert( pTarget[j].eType==JSON_STRING );
      assert( pTarget[j].jnFlags & JNODE_LABEL );
      assert( (pPatch[i].jnFlags & JNODE_RAW)==0 );
      if( pTarget[j].n==nKey && strncmp(pTarget[j].u.zJContent,zKey,nKey)==0 ){
        if( pTarget[j+1].jnFlags & (JNODE_REMOVE|JNODE_PATCH) ) break;
        if( pPatch[i+1].eType==JSON_NULL ){
          pTarget[j+1].jnFlags |= JNODE_REMOVE;
        }else{
          JsonNode *pNew = jsonMergePatch(pParse, iTarget+j+1, &pPatch[i+1]);
          if( pNew==0 ) return 0;
          pTarget = &pParse->aNode[iTarget];
          if( pNew!=&pTarget[j+1] ){
            pTarget[j+1].u.pPatch = pNew;
            pTarget[j+1].jnFlags |= JNODE_PATCH;
          }
        }
        break;
      }
    }
    if( j>=pTarget->n && pPatch[i+1].eType!=JSON_NULL ){
      int iStart, iPatch;
      iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);
      jsonParseAddNode(pParse, JSON_STRING, nKey, zKey);
      iPatch = jsonParseAddNode(pParse, JSON_TRUE, 0, 0);
      if( pParse->oom ) return 0;
      jsonRemoveAllNulls(pPatch);
      pTarget = &pParse->aNode[iTarget];
      pParse->aNode[iRoot].jnFlags |= JNODE_APPEND;
      pParse->aNode[iRoot].u.iAppend = iStart - iRoot;
      iRoot = iStart;
      pParse->aNode[iPatch].jnFlags |= JNODE_PATCH;
      pParse->aNode[iPatch].u.pPatch = &pPatch[i+1];
    }
  }
  return pTarget;
}

/*
** Implementation of the json_mergepatch(JSON1,JSON2) function.  Return a JSON
** object that is the result of running the RFC 7396 MergePatch() algorithm
** on the two arguments.
*/
static void jsonPatchFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;     /* The JSON that is being patched */
  JsonParse y;     /* The patch */
  JsonNode *pResult;   /* The result of the merge */

  UNUSED_PARAM(argc);
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  if( jsonParse(&y, ctx, (const char*)sqlite3_value_text(argv[1])) ){
    jsonParseReset(&x);
    return;
  }
  pResult = jsonMergePatch(&x, 0, y.aNode);
  assert( pResult!=0 || x.oom );
  if( pResult ){
    jsonReturnJson(pResult, ctx, 0);
  }else{
    sqlite3_result_error_nomem(ctx);
  }
  jsonParseReset(&x);
  jsonParseReset(&y);
}


/*
** Implementation of the json_object(NAME,VALUE,...) function.  Return a JSON
** object that contains all name/value given in arguments.  Or if any name
** is not a string or if any value is a BLOB, throw an error.
*/
static void jsonObjectFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  int i;
  JsonString jx;
  const char *z;
  u32 n;

  if( argc&1 ){
    sqlite3_result_error(ctx, "json_object() requires an even number "
                                  "of arguments", -1);
    return;
  }
  jsonInit(&jx, ctx);
  jsonAppendChar(&jx, '{');
  for(i=0; i<argc; i+=2){
    if( sqlite3_value_type(argv[i])!=SQLITE_TEXT ){
      sqlite3_result_error(ctx, "json_object() labels must be TEXT", -1);
      jsonReset(&jx);
      return;
    }
    jsonAppendSeparator(&jx);
    z = (const char*)sqlite3_value_text(argv[i]);
    n = (u32)sqlite3_value_bytes(argv[i]);
    jsonAppendString(&jx, z, n);
    jsonAppendChar(&jx, ':');
    jsonAppendValue(&jx, argv[i+1]);
  }
  jsonAppendChar(&jx, '}');
  jsonResult(&jx);
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}


/*
** json_remove(JSON, PATH, ...)
**
** Remove the named elements from JSON and return the result.  malformed
** JSON or PATH arguments result in an error.
*/
static void jsonRemoveFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  u32 i;

  if( argc<1 ) return;
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  assert( x.nNode );
  for(i=1; i<(u32)argc; i++){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    if( zPath==0 ) goto remove_done;
    pNode = jsonLookup(&x, zPath, 0, ctx);
    if( x.nErr ) goto remove_done;
    if( pNode ) pNode->jnFlags |= JNODE_REMOVE;
  }
  if( (x.aNode[0].jnFlags & JNODE_REMOVE)==0 ){
    jsonReturnJson(x.aNode, ctx, 0);
  }
remove_done:
  jsonParseReset(&x);
}

/*
** json_replace(JSON, PATH, VALUE, ...)
**
** Replace the value at PATH with VALUE.  If PATH does not already exist,
** this routine is a no-op.  If JSON or PATH is malformed, throw an error.
*/
static void jsonReplaceFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  u32 i;

  if( argc<1 ) return;
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, "replace");
    return;
  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  assert( x.nNode );
  for(i=1; i<(u32)argc; i+=2){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    pNode = jsonLookup(&x, zPath, 0, ctx);
    if( x.nErr ) goto replace_err;
    if( pNode ){
      pNode->jnFlags |= (u8)JNODE_REPLACE;
      pNode->u.iReplace = i + 1;
    }
  }
  if( x.aNode[0].jnFlags & JNODE_REPLACE ){
    sqlite3_result_value(ctx, argv[x.aNode[0].u.iReplace]);
  }else{
    jsonReturnJson(x.aNode, ctx, argv);
  }
replace_err:
  jsonParseReset(&x);
}

/*
** json_set(JSON, PATH, VALUE, ...)
**
** Set the value at PATH to VALUE.  Create the PATH if it does not already
** exist.  Overwrite existing values that do exist.
** If JSON or PATH is malformed, throw an error.
**
** json_insert(JSON, PATH, VALUE, ...)
**
** Create PATH and initialize it to VALUE.  If PATH already exists, this
** routine is a no-op.  If JSON or PATH is malformed, throw an error.
*/
static void jsonSetFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  u32 i;
  int bApnd;
  int bIsSet = *(int*)sqlite3_user_data(ctx);

  if( argc<1 ) return;
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, bIsSet ? "set" : "insert");
    return;
  }
  if( jsonParse(&x, ctx, (const char*)sqlite3_value_text(argv[0])) ) return;
  assert( x.nNode );
  for(i=1; i<(u32)argc; i+=2){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    bApnd = 0;
    pNode = jsonLookup(&x, zPath, &bApnd, ctx);
    if( x.oom ){
      sqlite3_result_error_nomem(ctx);
      goto jsonSetDone;
    }else if( x.nErr ){
      goto jsonSetDone;
    }else if( pNode && (bApnd || bIsSet) ){
      pNode->jnFlags |= (u8)JNODE_REPLACE;
      pNode->u.iReplace = i + 1;
    }
  }
  if( x.aNode[0].jnFlags & JNODE_REPLACE ){
    sqlite3_result_value(ctx, argv[x.aNode[0].u.iReplace]);
  }else{
    jsonReturnJson(x.aNode, ctx, argv);
  }
jsonSetDone:
  jsonParseReset(&x);
}

/*
** json_type(JSON)
** json_type(JSON, PATH)
**
** Return the top-level "type" of a JSON string.  Throw an error if
** either the JSON or PATH inputs are not well-formed.
*/
static void jsonTypeFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  const char *zPath;
  JsonNode *pNode;

  p = jsonParseCached(ctx, argv, ctx);
  if( p==0 ) return;
  if( argc==2 ){
    zPath = (const char*)sqlite3_value_text(argv[1]);
    pNode = jsonLookup(p, zPath, 0, ctx);
  }else{
    pNode = p->aNode;
  }
  if( pNode ){
    sqlite3_result_text(ctx, jsonType[pNode->eType], -1, SQLITE_STATIC);
  }
}

/*
** json_valid(JSON)
**
** Return 1 if JSON is a well-formed JSON string according to RFC-7159.
** Return 0 otherwise.
*/
static void jsonValidFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  UNUSED_PARAM(argc);
  p = jsonParseCached(ctx, argv, 0);
  sqlite3_result_int(ctx, p!=0);
}


/****************************************************************************
** Aggregate SQL function implementations
****************************************************************************/
/*
** json_group_array(VALUE)
**
** Return a JSON array composed of all values in the aggregate.
*/
static void jsonArrayStep(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonString *pStr;
  UNUSED_PARAM(argc);
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
  if( pStr ){
    if( pStr->zBuf==0 ){
      jsonInit(pStr, ctx);
      jsonAppendChar(pStr, '[');
    }else{
      jsonAppendChar(pStr, ',');
      pStr->pCtx = ctx;
    }
    jsonAppendValue(pStr, argv[0]);
  }
}
static void jsonArrayCompute(sqlite3_context *ctx, int isFinal){
  JsonString *pStr;
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
  if( pStr ){
    pStr->pCtx = ctx;
    jsonAppendChar(pStr, ']');
    if( pStr->bErr ){
      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
      assert( pStr->bStatic );
    }else if( isFinal ){
      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
                          pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
      pStr->bStatic = 1;
    }else{
      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed, SQLITE_TRANSIENT);
      pStr->nUsed--;
    }
  }else{
    sqlite3_result_text(ctx, "[]", 2, SQLITE_STATIC);
  }
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}
static void jsonArrayValue(sqlite3_context *ctx){
  jsonArrayCompute(ctx, 0);
}
static void jsonArrayFinal(sqlite3_context *ctx){
  jsonArrayCompute(ctx, 1);
}

#ifndef SQLITE_OMIT_WINDOWFUNC
/*
** This method works for both json_group_array() and json_group_object().
** It works by removing the first element of the group by searching forward
** to the first comma (",") that is not within a string and deleting all
** text through that comma.
*/
static void jsonGroupInverse(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  int i;
  int inStr = 0;
  char *z;
  JsonString *pStr;
  UNUSED_PARAM(argc);
  UNUSED_PARAM(argv);
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
#ifdef NEVER
  /* pStr is always non-NULL since jsonArrayStep() or jsonObjectStep() will
  ** always have been called to initalize it */
  if( NEVER(!pStr) ) return;
#endif
  z = pStr->zBuf;
  for(i=1; z[i]!=',' || inStr; i++){
    assert( i<pStr->nUsed );
    if( z[i]=='"' ){
      inStr = !inStr;
    }else if( z[i]=='\\' ){
      i++;
    }
  }
  pStr->nUsed -= i;      
  memmove(&z[1], &z[i+1], pStr->nUsed-1);
}
#else
# define jsonGroupInverse 0
#endif


/*
** json_group_obj(NAME,VALUE)
**
** Return a JSON object composed of all names and values in the aggregate.
*/
static void jsonObjectStep(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonString *pStr;
  const char *z;
  u32 n;
  UNUSED_PARAM(argc);
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, sizeof(*pStr));
  if( pStr ){
    if( pStr->zBuf==0 ){
      jsonInit(pStr, ctx);
      jsonAppendChar(pStr, '{');
    }else{
      jsonAppendChar(pStr, ',');
      pStr->pCtx = ctx;
    }
    z = (const char*)sqlite3_value_text(argv[0]);
    n = (u32)sqlite3_value_bytes(argv[0]);
    jsonAppendString(pStr, z, n);
    jsonAppendChar(pStr, ':');
    jsonAppendValue(pStr, argv[1]);
  }
}
static void jsonObjectCompute(sqlite3_context *ctx, int isFinal){
  JsonString *pStr;
  pStr = (JsonString*)sqlite3_aggregate_context(ctx, 0);
  if( pStr ){
    jsonAppendChar(pStr, '}');
    if( pStr->bErr ){
      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
      assert( pStr->bStatic );
    }else if( isFinal ){
      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed,
                          pStr->bStatic ? SQLITE_TRANSIENT : sqlite3_free);
      pStr->bStatic = 1;
    }else{
      sqlite3_result_text(ctx, pStr->zBuf, pStr->nUsed, SQLITE_TRANSIENT);
      pStr->nUsed--;
    }
  }else{
    sqlite3_result_text(ctx, "{}", 2, SQLITE_STATIC);
  }
  sqlite3_result_subtype(ctx, JSON_SUBTYPE);
}
static void jsonObjectValue(sqlite3_context *ctx){
  jsonObjectCompute(ctx, 0);
}
static void jsonObjectFinal(sqlite3_context *ctx){
  jsonObjectCompute(ctx, 1);
}



#ifndef SQLITE_OMIT_VIRTUALTABLE
/****************************************************************************
** The json_each virtual table
****************************************************************************/
typedef struct JsonEachCursor JsonEachCursor;
struct JsonEachCursor {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  u32 iRowid;                /* The rowid */
  u32 iBegin;                /* The first node of the scan */
  u32 i;                     /* Index in sParse.aNode[] of current row */
  u32 iEnd;                  /* EOF when i equals or exceeds this value */
  u8 eType;                  /* Type of top-level element */
  u8 bRecursive;             /* True for json_tree().  False for json_each() */
  char *zJson;               /* Input JSON */
  char *zRoot;               /* Path by which to filter zJson */
  JsonParse sParse;          /* Parse of the input JSON */
};

/* Constructor for the json_each virtual table */
static int jsonEachConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  sqlite3_vtab *pNew;
  int rc;

/* Column numbers */
#define JEACH_KEY     0
#define JEACH_VALUE   1
#define JEACH_TYPE    2
#define JEACH_ATOM    3
#define JEACH_ID      4
#define JEACH_PARENT  5
#define JEACH_FULLKEY 6
#define JEACH_PATH    7
#define JEACH_JSON    8
#define JEACH_ROOT    9

  UNUSED_PARAM(pzErr);
  UNUSED_PARAM(argv);
  UNUSED_PARAM(argc);
  UNUSED_PARAM(pAux);
  rc = sqlite3_declare_vtab(db, 
     "CREATE TABLE x(key,value,type,atom,id,parent,fullkey,path,"
                    "json HIDDEN,root HIDDEN)");
  if( rc==SQLITE_OK ){
    pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
  }
  return rc;
}

/* destructor for json_each virtual table */
static int jsonEachDisconnect(sqlite3_vtab *pVtab){
  sqlite3_free(pVtab);
  return SQLITE_OK;
}

/* constructor for a JsonEachCursor object for json_each(). */
static int jsonEachOpenEach(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  JsonEachCursor *pCur;

  UNUSED_PARAM(p);
  pCur = sqlite3_malloc( sizeof(*pCur) );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur));
  *ppCursor = &pCur->base;
  return SQLITE_OK;
}

/* constructor for a JsonEachCursor object for json_tree(). */
static int jsonEachOpenTree(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){
  int rc = jsonEachOpenEach(p, ppCursor);
  if( rc==SQLITE_OK ){
    JsonEachCursor *pCur = (JsonEachCursor*)*ppCursor;
    pCur->bRecursive = 1;
  }
  return rc;
}

/* Reset a JsonEachCursor back to its original state.  Free any memory
** held. */
static void jsonEachCursorReset(JsonEachCursor *p){
  sqlite3_free(p->zJson);
  sqlite3_free(p->zRoot);
  jsonParseReset(&p->sParse);
  p->iRowid = 0;
  p->i = 0;
  p->iEnd = 0;
  p->eType = 0;
  p->zJson = 0;
  p->zRoot = 0;
}

/* Destructor for a jsonEachCursor object */
static int jsonEachClose(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  jsonEachCursorReset(p);
  sqlite3_free(cur);
  return SQLITE_OK;
}

/* Return TRUE if the jsonEachCursor object has been advanced off the end
** of the JSON object */
static int jsonEachEof(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  return p->i >= p->iEnd;
}

/* Advance the cursor to the next element for json_tree() */
static int jsonEachNext(sqlite3_vtab_cursor *cur){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  if( p->bRecursive ){
    if( p->sParse.aNode[p->i].jnFlags & JNODE_LABEL ) p->i++;
    p->i++;
    p->iRowid++;
    if( p->i<p->iEnd ){
      u32 iUp = p->sParse.aUp[p->i];
      JsonNode *pUp = &p->sParse.aNode[iUp];
      p->eType = pUp->eType;
      if( pUp->eType==JSON_ARRAY ){
        if( iUp==p->i-1 ){
          pUp->u.iKey = 0;
        }else{
          pUp->u.iKey++;
        }
      }
    }
  }else{
    switch( p->eType ){
      case JSON_ARRAY: {
        p->i += jsonNodeSize(&p->sParse.aNode[p->i]);
        p->iRowid++;
        break;
      }
      case JSON_OBJECT: {
        p->i += 1 + jsonNodeSize(&p->sParse.aNode[p->i+1]);
        p->iRowid++;
        break;
      }
      default: {
        p->i = p->iEnd;
        break;
      }
    }
  }
  return SQLITE_OK;
}

/* Append the name of the path for element i to pStr
*/
static void jsonEachComputePath(
  JsonEachCursor *p,       /* The cursor */
  JsonString *pStr,        /* Write the path here */
  u32 i                    /* Path to this element */
){
  JsonNode *pNode, *pUp;
  u32 iUp;
  if( i==0 ){
    jsonAppendChar(pStr, '$');
    return;
  }
  iUp = p->sParse.aUp[i];
  jsonEachComputePath(p, pStr, iUp);
  pNode = &p->sParse.aNode[i];
  pUp = &p->sParse.aNode[iUp];
  if( pUp->eType==JSON_ARRAY ){
    jsonPrintf(30, pStr, "[%d]", pUp->u.iKey);
  }else{
    assert( pUp->eType==JSON_OBJECT );
    if( (pNode->jnFlags & JNODE_LABEL)==0 ) pNode--;
    assert( pNode->eType==JSON_STRING );
    assert( pNode->jnFlags & JNODE_LABEL );
    jsonPrintf(pNode->n+1, pStr, ".%.*s", pNode->n-2, pNode->u.zJContent+1);
  }
}

/* Return the value of a column */
static int jsonEachColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  JsonNode *pThis = &p->sParse.aNode[p->i];
  switch( i ){
    case JEACH_KEY: {
      if( p->i==0 ) break;
      if( p->eType==JSON_OBJECT ){
        jsonReturn(pThis, ctx, 0);
      }else if( p->eType==JSON_ARRAY ){
        u32 iKey;
        if( p->bRecursive ){
          if( p->iRowid==0 ) break;
          iKey = p->sParse.aNode[p->sParse.aUp[p->i]].u.iKey;
        }else{
          iKey = p->iRowid;
        }
        sqlite3_result_int64(ctx, (sqlite3_int64)iKey);
      }
      break;
    }
    case JEACH_VALUE: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      jsonReturn(pThis, ctx, 0);
      break;
    }
    case JEACH_TYPE: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      sqlite3_result_text(ctx, jsonType[pThis->eType], -1, SQLITE_STATIC);
      break;
    }
    case JEACH_ATOM: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      if( pThis->eType>=JSON_ARRAY ) break;
      jsonReturn(pThis, ctx, 0);
      break;
    }
    case JEACH_ID: {
      sqlite3_result_int64(ctx, 
         (sqlite3_int64)p->i + ((pThis->jnFlags & JNODE_LABEL)!=0));
      break;
    }
    case JEACH_PARENT: {
      if( p->i>p->iBegin && p->bRecursive ){
        sqlite3_result_int64(ctx, (sqlite3_int64)p->sParse.aUp[p->i]);
      }
      break;
    }
    case JEACH_FULLKEY: {
      JsonString x;
      jsonInit(&x, ctx);
      if( p->bRecursive ){
        jsonEachComputePath(p, &x, p->i);
      }else{
        if( p->zRoot ){
          jsonAppendRaw(&x, p->zRoot, (int)strlen(p->zRoot));
        }else{
          jsonAppendChar(&x, '$');
        }
        if( p->eType==JSON_ARRAY ){
          jsonPrintf(30, &x, "[%d]", p->iRowid);
        }else if( p->eType==JSON_OBJECT ){
          jsonPrintf(pThis->n, &x, ".%.*s", pThis->n-2, pThis->u.zJContent+1);
        }
      }
      jsonResult(&x);
      break;
    }
    case JEACH_PATH: {
      if( p->bRecursive ){
        JsonString x;
        jsonInit(&x, ctx);
        jsonEachComputePath(p, &x, p->sParse.aUp[p->i]);
        jsonResult(&x);
        break;
      }
      /* For json_each() path and root are the same so fall through
      ** into the root case */
    }
    default: {
      const char *zRoot = p->zRoot;
      if( zRoot==0 ) zRoot = "$";
      sqlite3_result_text(ctx, zRoot, -1, SQLITE_STATIC);
      break;
    }
    case JEACH_JSON: {
      assert( i==JEACH_JSON );
      sqlite3_result_text(ctx, p->sParse.zJson, -1, SQLITE_STATIC);
      break;
    }
  }
  return SQLITE_OK;
}

/* Return the current rowid value */
static int jsonEachRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  *pRowid = p->iRowid;
  return SQLITE_OK;
}

/* The query strategy is to look for an equality constraint on the json
** column.  Without such a constraint, the table cannot operate.  idxNum is
** 1 if the constraint is found, 3 if the constraint and zRoot are found,
** and 0 otherwise.
*/
static int jsonEachBestIndex(
  sqlite3_vtab *tab,
  sqlite3_index_info *pIdxInfo
){
  int i;
  int jsonIdx = -1;
  int rootIdx = -1;
  const struct sqlite3_index_constraint *pConstraint;

  UNUSED_PARAM(tab);
  pConstraint = pIdxInfo->aConstraint;
  for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
    if( pConstraint->usable==0 ) continue;
    if( pConstraint->op!=SQLITE_INDEX_CONSTRAINT_EQ ) continue;
    switch( pConstraint->iColumn ){
      case JEACH_JSON:   jsonIdx = i;    break;
      case JEACH_ROOT:   rootIdx = i;    break;
      default:           /* no-op */     break;
    }
  }
  if( jsonIdx<0 ){
    pIdxInfo->idxNum = 0;
    pIdxInfo->estimatedCost = 1e99;
  }else{
    pIdxInfo->estimatedCost = 1.0;
    pIdxInfo->aConstraintUsage[jsonIdx].argvIndex = 1;
    pIdxInfo->aConstraintUsage[jsonIdx].omit = 1;
    if( rootIdx<0 ){
      pIdxInfo->idxNum = 1;
    }else{
      pIdxInfo->aConstraintUsage[rootIdx].argvIndex = 2;
      pIdxInfo->aConstraintUsage[rootIdx].omit = 1;
      pIdxInfo->idxNum = 3;
    }
  }
  return SQLITE_OK;
}

/* Start a search on a new JSON string */
static int jsonEachFilter(
  sqlite3_vtab_cursor *cur,
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  const char *z;
  const char *zRoot = 0;
  sqlite3_int64 n;

  UNUSED_PARAM(idxStr);
  UNUSED_PARAM(argc);
  jsonEachCursorReset(p);
  if( idxNum==0 ) return SQLITE_OK;
  z = (const char*)sqlite3_value_text(argv[0]);
  if( z==0 ) return SQLITE_OK;
  n = sqlite3_value_bytes(argv[0]);
  p->zJson = sqlite3_malloc64( n+1 );
  if( p->zJson==0 ) return SQLITE_NOMEM;
  memcpy(p->zJson, z, (size_t)n+1);
  if( jsonParse(&p->sParse, 0, p->zJson) ){
    int rc = SQLITE_NOMEM;
    if( p->sParse.oom==0 ){
      sqlite3_free(cur->pVtab->zErrMsg);
      cur->pVtab->zErrMsg = sqlite3_mprintf("malformed JSON");
      if( cur->pVtab->zErrMsg ) rc = SQLITE_ERROR;
    }
    jsonEachCursorReset(p);
    return rc;
  }else if( p->bRecursive && jsonParseFindParents(&p->sParse) ){
    jsonEachCursorReset(p);
    return SQLITE_NOMEM;
  }else{
    JsonNode *pNode = 0;
    if( idxNum==3 ){
      const char *zErr = 0;
      zRoot = (const char*)sqlite3_value_text(argv[1]);
      if( zRoot==0 ) return SQLITE_OK;
      n = sqlite3_value_bytes(argv[1]);
      p->zRoot = sqlite3_malloc64( n+1 );
      if( p->zRoot==0 ) return SQLITE_NOMEM;
      memcpy(p->zRoot, zRoot, (size_t)n+1);
      if( zRoot[0]!='$' ){
        zErr = zRoot;
      }else{
        pNode = jsonLookupStep(&p->sParse, 0, p->zRoot+1, 0, &zErr);
      }
      if( zErr ){
        sqlite3_free(cur->pVtab->zErrMsg);
        cur->pVtab->zErrMsg = jsonPathSyntaxError(zErr);
        jsonEachCursorReset(p);
        return cur->pVtab->zErrMsg ? SQLITE_ERROR : SQLITE_NOMEM;
      }else if( pNode==0 ){
        return SQLITE_OK;
      }
    }else{
      pNode = p->sParse.aNode;
    }
    p->iBegin = p->i = (int)(pNode - p->sParse.aNode);
    p->eType = pNode->eType;
    if( p->eType>=JSON_ARRAY ){
      pNode->u.iKey = 0;
      p->iEnd = p->i + pNode->n + 1;
      if( p->bRecursive ){
        p->eType = p->sParse.aNode[p->sParse.aUp[p->i]].eType;
        if( p->i>0 && (p->sParse.aNode[p->i-1].jnFlags & JNODE_LABEL)!=0 ){
          p->i--;
        }
      }else{
        p->i++;
      }
    }else{
      p->iEnd = p->i+1;
    }
  }
  return SQLITE_OK;
}

/* The methods of the json_each virtual table */
static sqlite3_module jsonEachModule = {
  0,                         /* iVersion */
  0,                         /* xCreate */
  jsonEachConnect,           /* xConnect */
  jsonEachBestIndex,         /* xBestIndex */
  jsonEachDisconnect,        /* xDisconnect */
  0,                         /* xDestroy */
  jsonEachOpenEach,          /* xOpen - open a cursor */
  jsonEachClose,             /* xClose - close a cursor */
  jsonEachFilter,            /* xFilter - configure scan constraints */
  jsonEachNext,              /* xNext - advance a cursor */
  jsonEachEof,               /* xEof - check for end of scan */
  jsonEachColumn,            /* xColumn - read data */
  jsonEachRowid,             /* xRowid - read data */
  0,                         /* xUpdate */
  0,                         /* xBegin */
  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
  0,                         /* xSavepoint */
  0,                         /* xRelease */
  0                          /* xRollbackTo */
};

/* The methods of the json_tree virtual table. */
static sqlite3_module jsonTreeModule = {
  0,                         /* iVersion */
  0,                         /* xCreate */
  jsonEachConnect,           /* xConnect */
  jsonEachBestIndex,         /* xBestIndex */
  jsonEachDisconnect,        /* xDisconnect */
  0,                         /* xDestroy */
  jsonEachOpenTree,          /* xOpen - open a cursor */
  jsonEachClose,             /* xClose - close a cursor */
  jsonEachFilter,            /* xFilter - configure scan constraints */
  jsonEachNext,              /* xNext - advance a cursor */
  jsonEachEof,               /* xEof - check for end of scan */
  jsonEachColumn,            /* xColumn - read data */
  jsonEachRowid,             /* xRowid - read data */
  0,                         /* xUpdate */
  0,                         /* xBegin */
  0,                         /* xSync */
  0,                         /* xCommit */
  0,                         /* xRollback */
  0,                         /* xFindMethod */
  0,                         /* xRename */
  0,                         /* xSavepoint */
  0,                         /* xRelease */
  0                          /* xRollbackTo */
};
#endif /* SQLITE_OMIT_VIRTUALTABLE */

/****************************************************************************
** The following routines are the only publically visible identifiers in this
** file.  Call the following routines in order to register the various SQL
** functions and the virtual table implemented by this file.
****************************************************************************/

SQLITE_PRIVATE int sqlite3Json1Init(sqlite3 *db){
  int rc = SQLITE_OK;
  unsigned int i;
  static const struct {
     const char *zName;
     int nArg;
     int flag;
     void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
  } aFunc[] = {
    { "json",                 1, 0,   jsonRemoveFunc        },
    { "json_array",          -1, 0,   jsonArrayFunc         },
    { "json_array_length",    1, 0,   jsonArrayLengthFunc   },
    { "json_array_length",    2, 0,   jsonArrayLengthFunc   },
    { "json_extract",        -1, 0,   jsonExtractFunc       },
    { "json_insert",         -1, 0,   jsonSetFunc           },
    { "json_object",         -1, 0,   jsonObjectFunc        },
    { "json_patch",           2, 0,   jsonPatchFunc         },
    { "json_quote",           1, 0,   jsonQuoteFunc         },
    { "json_remove",         -1, 0,   jsonRemoveFunc        },
    { "json_replace",        -1, 0,   jsonReplaceFunc       },
    { "json_set",            -1, 1,   jsonSetFunc           },
    { "json_type",            1, 0,   jsonTypeFunc          },
    { "json_type",            2, 0,   jsonTypeFunc          },
    { "json_valid",           1, 0,   jsonValidFunc         },

#if SQLITE_DEBUG
    /* DEBUG and TESTING functions */
    { "json_parse",           1, 0,   jsonParseFunc         },
    { "json_test1",           1, 0,   jsonTest1Func         },
#endif
  };
  static const struct {
     const char *zName;
     int nArg;
     void (*xStep)(sqlite3_context*,int,sqlite3_value**);
     void (*xFinal)(sqlite3_context*);
     void (*xValue)(sqlite3_context*);
  } aAgg[] = {
    { "json_group_array",     1,
      jsonArrayStep,   jsonArrayFinal,  jsonArrayValue  },
    { "json_group_object",    2,
      jsonObjectStep,  jsonObjectFinal, jsonObjectValue },
  };
#ifndef SQLITE_OMIT_VIRTUALTABLE
  static const struct {
     const char *zName;
     sqlite3_module *pModule;
  } aMod[] = {
    { "json_each",            &jsonEachModule               },
    { "json_tree",            &jsonTreeModule               },
  };
#endif
  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zName, aFunc[i].nArg,
                                 SQLITE_UTF8 | SQLITE_DETERMINISTIC, 
                                 (void*)&aFunc[i].flag,
                                 aFunc[i].xFunc, 0, 0);
  }
#ifndef SQLITE_OMIT_WINDOWFUNC
  for(i=0; i<sizeof(aAgg)/sizeof(aAgg[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_window_function(db, aAgg[i].zName, aAgg[i].nArg,
                                 SQLITE_UTF8 | SQLITE_DETERMINISTIC, 0,
                                 aAgg[i].xStep, aAgg[i].xFinal,
                                 aAgg[i].xValue, jsonGroupInverse, 0);
  }
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  for(i=0; i<sizeof(aMod)/sizeof(aMod[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_module(db, aMod[i].zName, aMod[i].pModule, 0);
  }
#endif
  return rc;
}


#ifndef SQLITE_CORE
#ifdef _WIN32
__declspec(dllexport)
#endif
SQLITE_API int sqlite3_json_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  (void)pzErrMsg;  /* Unused parameter */
  return sqlite3Json1Init(db);
}
#endif
#endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_JSON1) */

/************** End of json1.c ***********************************************/
/************** Begin file rtree.c *******************************************/
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**

  int iNodeSize;              /* Size in bytes of each node in the node table */
  u8 nDim;                    /* Number of dimensions */
  u8 nDim2;                   /* Twice the number of dimensions */
  u8 eCoordType;              /* RTREE_COORD_REAL32 or RTREE_COORD_INT32 */
  u8 nBytesPerCell;           /* Bytes consumed per cell */
  u8 inWrTrans;               /* True if inside write transaction */
  u8 nAux;                    /* # of auxiliary columns in %_rowid */
  u8 nAuxNotNull;             /* Number of initial not-null aux columns */
  int iDepth;                 /* Current depth of the r-tree structure */
  char *zDb;                  /* Name of database containing r-tree table */
  char *zName;                /* Name of r-tree table */ 
  u32 nBusy;                  /* Current number of users of this structure */
  i64 nRowEst;                /* Estimated number of rows in this table */
  u32 nCursor;                /* Number of open cursors */
  u32 nNodeRef;               /* Number RtreeNodes with positive nRef */

  }
  return rc;
}

/*
** Select a currently unused rowid for a new r-tree record.
*/
static int rtreeNewRowid(Rtree *pRtree, i64 *piRowid){
  int rc;
  sqlite3_bind_null(pRtree->pWriteRowid, 1);
  sqlite3_bind_null(pRtree->pWriteRowid, 2);
  sqlite3_step(pRtree->pWriteRowid);
  rc = sqlite3_reset(pRtree->pWriteRowid);
  *piRowid = sqlite3_last_insert_rowid(pRtree->db);
  return rc;

  */
  if( rc==SQLITE_OK && nData>1 ){
    /* Insert the new record into the r-tree */
    RtreeNode *pLeaf = 0;

    /* Figure out the rowid of the new row. */
    if( bHaveRowid==0 ){
      rc = rtreeNewRowid(pRtree, &cell.iRowid);
    }
    *pRowid = cell.iRowid;

    if( rc==SQLITE_OK ){
      rc = ChooseLeaf(pRtree, &cell, 0, &pLeaf);
    }
    if( rc==SQLITE_OK ){

    }else{
      sqlite3_str *p = sqlite3_str_new(db);
      int ii;
      char *zSql;
      sqlite3_str_appendf(p, "UPDATE \"%w\".\"%w_rowid\"SET ", zDb, zPrefix);
      for(ii=0; ii<pRtree->nAux; ii++){
        if( ii ) sqlite3_str_append(p, ",", 1);
        if( ii<pRtree->nAuxNotNull ){
          sqlite3_str_appendf(p,"a%d=coalesce(?%d,a%d)",ii,ii+2,ii);
        }else{
          sqlite3_str_appendf(p,"a%d=?%d",ii,ii+2);
        }
      }
      sqlite3_str_appendf(p, " WHERE rowid=?1");
      zSql = sqlite3_str_finish(p);
      if( zSql==0 ){
        rc = SQLITE_NOMEM;
      }else{
        rc = sqlite3_prepare_v3(db, zSql, -1, SQLITE_PREPARE_PERSISTENT,

    }else{
      sqlite3_result_error_code(ctx, rc);
    }
    sqlite3_free(zReport);
  }
}

/* Conditionally include the geopoly code */
#ifdef SQLITE_ENABLE_GEOPOLY
/************** Include geopoly.c in the middle of rtree.c *******************/
/************** Begin file geopoly.c *****************************************/
/*
** 2018-05-25
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file implements an alternative R-Tree virtual table that
** uses polygons to express the boundaries of 2-dimensional objects.
**
** This file is #include-ed onto the end of "rtree.c" so that it has
** access to all of the R-Tree internals.
*/
/* #include <stdlib.h> */

/* Enable -DGEOPOLY_ENABLE_DEBUG for debugging facilities */
#ifdef GEOPOLY_ENABLE_DEBUG
  static int geo_debug = 0;
# define GEODEBUG(X) if(geo_debug)printf X
#else
# define GEODEBUG(X)
#endif

#ifndef JSON_NULL   /* The following stuff repeats things found in json1 */
/*
** Versions of isspace(), isalnum() and isdigit() to which it is safe
** to pass signed char values.
*/
#ifdef sqlite3Isdigit
   /* Use the SQLite core versions if this routine is part of the
   ** SQLite amalgamation */
#  define safe_isdigit(x)  sqlite3Isdigit(x)
#  define safe_isalnum(x)  sqlite3Isalnum(x)
#  define safe_isxdigit(x) sqlite3Isxdigit(x)
#else
   /* Use the standard library for separate compilation */
#include <ctype.h>  /* amalgamator: keep */
#  define safe_isdigit(x)  isdigit((unsigned char)(x))
#  define safe_isalnum(x)  isalnum((unsigned char)(x))
#  define safe_isxdigit(x) isxdigit((unsigned char)(x))
#endif

/*
** Growing our own isspace() routine this way is twice as fast as
** the library isspace() function.
*/
static const char geopolyIsSpace[] = {
  0, 0, 0, 0, 0, 0, 0, 0,     0, 1, 1, 0, 0, 1, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  1, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0,     0, 0, 0, 0, 0, 0, 0, 0,
};
#define safe_isspace(x) (geopolyIsSpace[(unsigned char)x])
#endif /* JSON NULL - back to original code */

/* Compiler and version */
#ifndef GCC_VERSION
#if defined(__GNUC__) && !defined(SQLITE_DISABLE_INTRINSIC)
# define GCC_VERSION (__GNUC__*1000000+__GNUC_MINOR__*1000+__GNUC_PATCHLEVEL__)
#else
# define GCC_VERSION 0
#endif
#endif
#ifndef MSVC_VERSION
#if defined(_MSC_VER) && !defined(SQLITE_DISABLE_INTRINSIC)
# define MSVC_VERSION _MSC_VER
#else
# define MSVC_VERSION 0
#endif
#endif

/* Datatype for coordinates
*/
typedef float GeoCoord;

/*
** Internal representation of a polygon.
**
** The polygon consists of a sequence of vertexes.  There is a line
** segment between each pair of vertexes, and one final segment from
** the last vertex back to the first.  (This differs from the GeoJSON
** standard in which the final vertex is a repeat of the first.)
**
** The polygon follows the right-hand rule.  The area to the right of
** each segment is "outside" and the area to the left is "inside".
**
** The on-disk representation consists of a 4-byte header followed by
** the values.  The 4-byte header is:
**
**      encoding    (1 byte)   0=big-endian, 1=little-endian
**      nvertex     (3 bytes)  Number of vertexes as a big-endian integer
*/
typedef struct GeoPoly GeoPoly;
struct GeoPoly {
  int nVertex;          /* Number of vertexes */
  unsigned char hdr[4]; /* Header for on-disk representation */
  GeoCoord a[2];    /* 2*nVertex values. X (longitude) first, then Y */
};

/*
** State of a parse of a GeoJSON input.
*/
typedef struct GeoParse GeoParse;
struct GeoParse {
  const unsigned char *z;   /* Unparsed input */
  int nVertex;              /* Number of vertexes in a[] */
  int nAlloc;               /* Space allocated to a[] */
  int nErr;                 /* Number of errors encountered */
  GeoCoord *a;          /* Array of vertexes.  From sqlite3_malloc64() */
};

/* Do a 4-byte byte swap */
static void geopolySwab32(unsigned char *a){
  unsigned char t = a[0];
  a[0] = a[3];
  a[3] = t;
  t = a[1];
  a[1] = a[2];
  a[2] = t;
}

/* Skip whitespace.  Return the next non-whitespace character. */
static char geopolySkipSpace(GeoParse *p){
  while( p->z[0] && safe_isspace(p->z[0]) ) p->z++;
  return p->z[0];
}

/* Parse out a number.  Write the value into *pVal if pVal!=0.
** return non-zero on success and zero if the next token is not a number.
*/
static int geopolyParseNumber(GeoParse *p, GeoCoord *pVal){
  char c = geopolySkipSpace(p);
  const unsigned char *z = p->z;
  int j = 0;
  int seenDP = 0;
  int seenE = 0;
  if( c=='-' ){
    j = 1;
    c = z[j];
  }
  if( c=='0' && z[j+1]>='0' && z[j+1]<='9' ) return 0;
  for(;; j++){
    c = z[j];
    if( c>='0' && c<='9' ) continue;
    if( c=='.' ){
      if( z[j-1]=='-' ) return 0;
      if( seenDP ) return 0;
      seenDP = 1;
      continue;
    }
    if( c=='e' || c=='E' ){
      if( z[j-1]<'0' ) return 0;
      if( seenE ) return -1;
      seenDP = seenE = 1;
      c = z[j+1];
      if( c=='+' || c=='-' ){
        j++;
        c = z[j+1];
      }
      if( c<'0' || c>'9' ) return 0;
      continue;
    }
    break;
  }
  if( z[j-1]<'0' ) return 0;
  if( pVal ) *pVal = atof((const char*)p->z);
  p->z += j;
  return 1;
}

/*
** If the input is a well-formed JSON array of coordinates with at least
** four coordinates and where each coordinate is itself a two-value array,
** then convert the JSON into a GeoPoly object and return a pointer to
** that object.
**
** If any error occurs, return NULL.
*/
static GeoPoly *geopolyParseJson(const unsigned char *z, int *pRc){
  GeoParse s;
  int rc = SQLITE_OK;
  memset(&s, 0, sizeof(s));
  s.z = z;
  if( geopolySkipSpace(&s)=='[' ){
    s.z++;
    while( geopolySkipSpace(&s)=='[' ){
      int ii = 0;
      char c;
      s.z++;
      if( s.nVertex<=s.nAlloc ){
        GeoCoord *aNew;
        s.nAlloc = s.nAlloc*2 + 16;
        aNew = sqlite3_realloc64(s.a, s.nAlloc*sizeof(GeoCoord)*2 );
        if( aNew==0 ){
          rc = SQLITE_NOMEM;
          s.nErr++;
          break;
        }
        s.a = aNew;
      }
      while( geopolyParseNumber(&s, ii<=1 ? &s.a[s.nVertex*2+ii] : 0) ){
        ii++;
        if( ii==2 ) s.nVertex++;
        c = geopolySkipSpace(&s);
        s.z++;
        if( c==',' ) continue;
        if( c==']' && ii>=2 ) break;
        s.nErr++;
        rc = SQLITE_ERROR;
        goto parse_json_err;
      }
      if( geopolySkipSpace(&s)==',' ){
        s.z++;
        continue;
      }
      break;
    }
    if( geopolySkipSpace(&s)==']'
     && s.nVertex>=4
     && s.a[0]==s.a[s.nVertex*2-2]
     && s.a[1]==s.a[s.nVertex*2-1]
     && (s.z++, geopolySkipSpace(&s)==0)
    ){
      int nByte;
      GeoPoly *pOut;
      int x = 1;
      s.nVertex--;  /* Remove the redundant vertex at the end */
      nByte = sizeof(GeoPoly) * s.nVertex*2*sizeof(GeoCoord);
      pOut = sqlite3_malloc64( nByte );
      x = 1;
      if( pOut==0 ) goto parse_json_err;
      pOut->nVertex = s.nVertex;
      memcpy(pOut->a, s.a, s.nVertex*2*sizeof(GeoCoord));
      pOut->hdr[0] = *(unsigned char*)&x;
      pOut->hdr[1] = (s.nVertex>>16)&0xff;
      pOut->hdr[2] = (s.nVertex>>8)&0xff;
      pOut->hdr[3] = s.nVertex&0xff;
      sqlite3_free(s.a);
      if( pRc ) *pRc = SQLITE_OK;
      return pOut;
    }else{
      s.nErr++;
      rc = SQLITE_ERROR;
    }
  }
parse_json_err:
  if( pRc ) *pRc = rc;
  sqlite3_free(s.a);
  return 0;
}

/*
** Given a function parameter, try to interpret it as a polygon, either
** in the binary format or JSON text.  Compute a GeoPoly object and
** return a pointer to that object.  Or if the input is not a well-formed
** polygon, put an error message in sqlite3_context and return NULL.
*/
static GeoPoly *geopolyFuncParam(
  sqlite3_context *pCtx,      /* Context for error messages */
  sqlite3_value *pVal,        /* The value to decode */
  int *pRc                    /* Write error here */
){
  GeoPoly *p = 0;
  int nByte;
  if( sqlite3_value_type(pVal)==SQLITE_BLOB
   && (nByte = sqlite3_value_bytes(pVal))>=(4+6*sizeof(GeoCoord))
  ){
    const unsigned char *a = sqlite3_value_blob(pVal);
    int nVertex;
    nVertex = (a[1]<<16) + (a[2]<<8) + a[3];
    if( (a[0]==0 || a[0]==1)
     && (nVertex*2*sizeof(GeoCoord) + 4)==nByte
    ){
      p = sqlite3_malloc64( sizeof(*p) + (nVertex-1)*2*sizeof(GeoCoord) );
      if( p==0 ){
        if( pRc ) *pRc = SQLITE_NOMEM;
        if( pCtx ) sqlite3_result_error_nomem(pCtx);
      }else{
        int x = 1;
        p->nVertex = nVertex;
        memcpy(p->hdr, a, nByte);
        if( a[0] != *(unsigned char*)&x ){
          int ii;
          for(ii=0; ii<nVertex*2; ii++){
            geopolySwab32((unsigned char*)&p->a[ii]);
          }
          p->hdr[0] ^= 1;
        }
      }
    }
    if( pRc ) *pRc = SQLITE_OK;
    return p;
  }else if( sqlite3_value_type(pVal)==SQLITE_TEXT ){
    const unsigned char *zJson = sqlite3_value_text(pVal);
    if( zJson==0 ){
      if( pRc ) *pRc = SQLITE_NOMEM;
      return 0;
    }
    return geopolyParseJson(zJson, pRc);
  }else{
    if( pRc ) *pRc = SQLITE_ERROR;
    return 0;
  }
}

/*
** Implementation of the geopoly_blob(X) function.
**
** If the input is a well-formed Geopoly BLOB or JSON string
** then return the BLOB representation of the polygon.  Otherwise
** return NULL.
*/
static void geopolyBlobFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p = geopolyFuncParam(context, argv[0], 0);
  if( p ){
    sqlite3_result_blob(context, p->hdr, 
       4+8*p->nVertex, SQLITE_TRANSIENT);
    sqlite3_free(p);
  }
}

/*
** SQL function:     geopoly_json(X)
**
** Interpret X as a polygon and render it as a JSON array
** of coordinates.  Or, if X is not a valid polygon, return NULL.
*/
static void geopolyJsonFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p = geopolyFuncParam(context, argv[0], 0);
  if( p ){
    sqlite3 *db = sqlite3_context_db_handle(context);
    sqlite3_str *x = sqlite3_str_new(db);
    int i;
    sqlite3_str_append(x, "[", 1);
    for(i=0; i<p->nVertex; i++){
      sqlite3_str_appendf(x, "[%!g,%!g],", p->a[i*2], p->a[i*2+1]);
    }
    sqlite3_str_appendf(x, "[%!g,%!g]]", p->a[0], p->a[1]);
    sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);
    sqlite3_free(p);
  }
}

/*
** SQL function:     geopoly_svg(X, ....)
**
** Interpret X as a polygon and render it as a SVG <polyline>.
** Additional arguments are added as attributes to the <polyline>.
*/
static void geopolySvgFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p = geopolyFuncParam(context, argv[0], 0);
  if( p ){
    sqlite3 *db = sqlite3_context_db_handle(context);
    sqlite3_str *x = sqlite3_str_new(db);
    int i;
    char cSep = '\'';
    sqlite3_str_appendf(x, "<polyline points=");
    for(i=0; i<p->nVertex; i++){
      sqlite3_str_appendf(x, "%c%g,%g", cSep, p->a[i*2], p->a[i*2+1]);
      cSep = ' ';
    }
    sqlite3_str_appendf(x, " %g,%g'", p->a[0], p->a[1]);
    for(i=1; i<argc; i++){
      const char *z = (const char*)sqlite3_value_text(argv[i]);
      if( z && z[0] ){
        sqlite3_str_appendf(x, " %s", z);
      }
    }
    sqlite3_str_appendf(x, "></polyline>");
    sqlite3_result_text(context, sqlite3_str_finish(x), -1, sqlite3_free);
    sqlite3_free(p);
  }
}

/*
** SQL Function:      geopoly_xform(poly, A, B, C, D, E, F)
**
** Transform and/or translate a polygon as follows:
**
**      x1 = A*x0 + B*y0 + E
**      y1 = C*x0 + D*y0 + F
**
** For a translation:
**
**      geopoly_xform(poly, 1, 0, 0, 1, x-offset, y-offset)
**
** Rotate by R around the point (0,0):
**
**      geopoly_xform(poly, cos(R), sin(R), -sin(R), cos(R), 0, 0)
*/
static void geopolyXformFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p = geopolyFuncParam(context, argv[0], 0);
  double A = sqlite3_value_double(argv[1]);
  double B = sqlite3_value_double(argv[2]);
  double C = sqlite3_value_double(argv[3]);
  double D = sqlite3_value_double(argv[4]);
  double E = sqlite3_value_double(argv[5]);
  double F = sqlite3_value_double(argv[6]);
  GeoCoord x1, y1, x0, y0;
  int ii;
  if( p ){
    for(ii=0; ii<p->nVertex; ii++){
      x0 = p->a[ii*2];
      y0 = p->a[ii*2+1];
      x1 = A*x0 + B*y0 + E;
      y1 = C*x0 + D*y0 + F;
      p->a[ii*2] = x1;
      p->a[ii*2+1] = y1;
    }
    sqlite3_result_blob(context, p->hdr, 
       4+8*p->nVertex, SQLITE_TRANSIENT);
    sqlite3_free(p);
  }
}

/*
** Implementation of the geopoly_area(X) function.
**
** If the input is a well-formed Geopoly BLOB then return the area
** enclosed by the polygon.  If the polygon circulates clockwise instead
** of counterclockwise (as it should) then return the negative of the
** enclosed area.  Otherwise return NULL.
*/
static void geopolyAreaFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p = geopolyFuncParam(context, argv[0], 0);
  if( p ){
    double rArea = 0.0;
    int ii;
    for(ii=0; ii<p->nVertex-1; ii++){
      rArea += (p->a[ii*2] - p->a[ii*2+2])           /* (x0 - x1) */
                * (p->a[ii*2+1] + p->a[ii*2+3])      /* (y0 + y1) */
                * 0.5;
    }
    rArea += (p->a[ii*2] - p->a[0])                  /* (xN - x0) */
             * (p->a[ii*2+1] + p->a[1])              /* (yN + y0) */
             * 0.5;
    sqlite3_result_double(context, rArea);
    sqlite3_free(p);
  }            
}

/*
** If pPoly is a polygon, compute its bounding box. Then:
**
**    (1) if aCoord!=0 store the bounding box in aCoord, returning NULL
**    (2) otherwise, compute a GeoPoly for the bounding box and return the
**        new GeoPoly
**
** If pPoly is NULL but aCoord is not NULL, then compute a new GeoPoly from
** the bounding box in aCoord and return a pointer to that GeoPoly.
*/
static GeoPoly *geopolyBBox(
  sqlite3_context *context,   /* For recording the error */
  sqlite3_value *pPoly,       /* The polygon */
  RtreeCoord *aCoord,         /* Results here */
  int *pRc                    /* Error code here */
){
  GeoPoly *pOut = 0;
  GeoPoly *p;
  float mnX, mxX, mnY, mxY;
  if( pPoly==0 && aCoord!=0 ){
    p = 0;
    mnX = aCoord[0].f;
    mxX = aCoord[1].f;
    mnY = aCoord[2].f;
    mxY = aCoord[3].f;
    goto geopolyBboxFill;
  }else{
    p = geopolyFuncParam(context, pPoly, pRc);
  }
  if( p ){
    int ii;
    mnX = mxX = p->a[0];
    mnY = mxY = p->a[1];
    for(ii=1; ii<p->nVertex; ii++){
      double r = p->a[ii*2];
      if( r<mnX ) mnX = r;
      else if( r>mxX ) mxX = r;
      r = p->a[ii*2+1];
      if( r<mnY ) mnY = r;
      else if( r>mxY ) mxY = r;
    }
    if( pRc ) *pRc = SQLITE_OK;
    if( aCoord==0 ){
      geopolyBboxFill:
      pOut = sqlite3_realloc(p, sizeof(GeoPoly)+sizeof(GeoCoord)*6);
      if( pOut==0 ){
        sqlite3_free(p);
        if( context ) sqlite3_result_error_nomem(context);
        if( pRc ) *pRc = SQLITE_NOMEM;
        return 0;
      }
      pOut->nVertex = 4;
      ii = 1;
      pOut->hdr[0] = *(unsigned char*)&ii;
      pOut->hdr[1] = 0;
      pOut->hdr[2] = 0;
      pOut->hdr[3] = 4;
      pOut->a[0] = mnX;
      pOut->a[1] = mnY;
      pOut->a[2] = mxX;
      pOut->a[3] = mnY;
      pOut->a[4] = mxX;
      pOut->a[5] = mxY;
      pOut->a[6] = mnX;
      pOut->a[7] = mxY;
    }else{
      sqlite3_free(p);
      aCoord[0].f = mnX;
      aCoord[1].f = mxX;
      aCoord[2].f = mnY;
      aCoord[3].f = mxY;
    }
  }
  return pOut;
}

/*
** Implementation of the geopoly_bbox(X) SQL function.
*/
static void geopolyBBoxFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p = geopolyBBox(context, argv[0], 0, 0);
  if( p ){
    sqlite3_result_blob(context, p->hdr, 
       4+8*p->nVertex, SQLITE_TRANSIENT);
    sqlite3_free(p);
  }
}

/*
** State vector for the geopoly_group_bbox() aggregate function.
*/
typedef struct GeoBBox GeoBBox;
struct GeoBBox {
  int isInit;
  RtreeCoord a[4];
};


/*
** Implementation of the geopoly_group_bbox(X) aggregate SQL function.
*/
static void geopolyBBoxStep(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  RtreeCoord a[4];
  int rc = SQLITE_OK;
  (void)geopolyBBox(context, argv[0], a, &rc);
  if( rc==SQLITE_OK ){
    GeoBBox *pBBox;
    pBBox = (GeoBBox*)sqlite3_aggregate_context(context, sizeof(*pBBox));
    if( pBBox==0 ) return;
    if( pBBox->isInit==0 ){
      pBBox->isInit = 1;
      memcpy(pBBox->a, a, sizeof(RtreeCoord)*4);
    }else{
      if( a[0].f < pBBox->a[0].f ) pBBox->a[0] = a[0];
      if( a[1].f > pBBox->a[1].f ) pBBox->a[1] = a[1];
      if( a[2].f < pBBox->a[2].f ) pBBox->a[2] = a[2];
      if( a[3].f > pBBox->a[3].f ) pBBox->a[3] = a[3];
    }
  }
}
static void geopolyBBoxFinal(
  sqlite3_context *context
){
  GeoPoly *p;
  GeoBBox *pBBox;
  pBBox = (GeoBBox*)sqlite3_aggregate_context(context, 0);
  if( pBBox==0 ) return;
  p = geopolyBBox(context, 0, pBBox->a, 0);
  if( p ){
    sqlite3_result_blob(context, p->hdr, 
       4+8*p->nVertex, SQLITE_TRANSIENT);
    sqlite3_free(p);
  }
}


/*
** Determine if point (x0,y0) is beneath line segment (x1,y1)->(x2,y2).
** Returns:
**
**    +2  x0,y0 is on the line segement
**
**    +1  x0,y0 is beneath line segment
**
**    0   x0,y0 is not on or beneath the line segment or the line segment
**        is vertical and x0,y0 is not on the line segment
**
** The left-most coordinate min(x1,x2) is not considered to be part of
** the line segment for the purposes of this analysis.
*/
static int pointBeneathLine(
  double x0, double y0,
  double x1, double y1,
  double x2, double y2
){
  double y;
  if( x0==x1 && y0==y1 ) return 2;
  if( x1<x2 ){
    if( x0<=x1 || x0>x2 ) return 0;
  }else if( x1>x2 ){
    if( x0<=x2 || x0>x1 ) return 0;
  }else{
    /* Vertical line segment */
    if( x0!=x1 ) return 0;
    if( y0<y1 && y0<y2 ) return 0;
    if( y0>y1 && y0>y2 ) return 0;
    return 2;
  }
  y = y1 + (y2-y1)*(x0-x1)/(x2-x1);
  if( y0==y ) return 2;
  if( y0<y ) return 1;
  return 0;
}

/*
** SQL function:    geopoly_contains_point(P,X,Y)
**
** Return +2 if point X,Y is within polygon P.
** Return +1 if point X,Y is on the polygon boundary.
** Return 0 if point X,Y is outside the polygon
*/
static void geopolyContainsPointFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);
  double x0 = sqlite3_value_double(argv[1]);
  double y0 = sqlite3_value_double(argv[2]);
  int v = 0;
  int cnt = 0;
  int ii;
  if( p1==0 ) return;
  for(ii=0; ii<p1->nVertex-1; ii++){
    v = pointBeneathLine(x0,y0,p1->a[ii*2],p1->a[ii*2+1],
                               p1->a[ii*2+2],p1->a[ii*2+3]);
    if( v==2 ) break;
    cnt += v;
  }
  if( v!=2 ){
    v = pointBeneathLine(x0,y0,p1->a[ii*2],p1->a[ii*2+1],
                               p1->a[0],p1->a[1]);
  }
  if( v==2 ){
    sqlite3_result_int(context, 1);
  }else if( ((v+cnt)&1)==0 ){
    sqlite3_result_int(context, 0);
  }else{
    sqlite3_result_int(context, 2);
  }
  sqlite3_free(p1);
}

/* Forward declaration */
static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2);

/*
** SQL function:    geopoly_within(P1,P2)
**
** Return +2 if P1 and P2 are the same polygon
** Return +1 if P2 is contained within P1
** Return 0 if any part of P2 is on the outside of P1
**
*/
static void geopolyWithinFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);
  GeoPoly *p2 = geopolyFuncParam(context, argv[1], 0);
  if( p1 && p2 ){
    int x = geopolyOverlap(p1, p2);
    if( x<0 ){
      sqlite3_result_error_nomem(context);
    }else{
      sqlite3_result_int(context, x==2 ? 1 : x==4 ? 2 : 0);
    }
  }
  sqlite3_free(p1);
  sqlite3_free(p2);
}

/* Objects used by the overlap algorihm. */
typedef struct GeoEvent GeoEvent;
typedef struct GeoSegment GeoSegment;
typedef struct GeoOverlap GeoOverlap;
struct GeoEvent {
  double x;              /* X coordinate at which event occurs */
  int eType;             /* 0 for ADD, 1 for REMOVE */
  GeoSegment *pSeg;      /* The segment to be added or removed */
  GeoEvent *pNext;       /* Next event in the sorted list */
};
struct GeoSegment {
  double C, B;           /* y = C*x + B */
  double y;              /* Current y value */
  float y0;              /* Initial y value */
  unsigned char side;    /* 1 for p1, 2 for p2 */
  unsigned int idx;      /* Which segment within the side */
  GeoSegment *pNext;     /* Next segment in a list sorted by y */
};
struct GeoOverlap {
  GeoEvent *aEvent;          /* Array of all events */
  GeoSegment *aSegment;      /* Array of all segments */
  int nEvent;                /* Number of events */
  int nSegment;              /* Number of segments */
};

/*
** Add a single segment and its associated events.
*/
static void geopolyAddOneSegment(
  GeoOverlap *p,
  GeoCoord x0,
  GeoCoord y0,
  GeoCoord x1,
  GeoCoord y1,
  unsigned char side,
  unsigned int idx
){
  GeoSegment *pSeg;
  GeoEvent *pEvent;
  if( x0==x1 ) return;  /* Ignore vertical segments */
  if( x0>x1 ){
    GeoCoord t = x0;
    x0 = x1;
    x1 = t;
    t = y0;
    y0 = y1;
    y1 = t;
  }
  pSeg = p->aSegment + p->nSegment;
  p->nSegment++;
  pSeg->C = (y1-y0)/(x1-x0);
  pSeg->B = y1 - x1*pSeg->C;
  pSeg->y0 = y0;
  pSeg->side = side;
  pSeg->idx = idx;
  pEvent = p->aEvent + p->nEvent;
  p->nEvent++;
  pEvent->x = x0;
  pEvent->eType = 0;
  pEvent->pSeg = pSeg;
  pEvent = p->aEvent + p->nEvent;
  p->nEvent++;
  pEvent->x = x1;
  pEvent->eType = 1;
  pEvent->pSeg = pSeg;
}
  


/*
** Insert all segments and events for polygon pPoly.
*/
static void geopolyAddSegments(
  GeoOverlap *p,          /* Add segments to this Overlap object */
  GeoPoly *pPoly,         /* Take all segments from this polygon */
  unsigned char side      /* The side of pPoly */
){
  unsigned int i;
  GeoCoord *x;
  for(i=0; i<(unsigned)pPoly->nVertex-1; i++){
    x = pPoly->a + (i*2);
    geopolyAddOneSegment(p, x[0], x[1], x[2], x[3], side, i);
  }
  x = pPoly->a + (i*2);
  geopolyAddOneSegment(p, x[0], x[1], pPoly->a[0], pPoly->a[1], side, i);
}

/*
** Merge two lists of sorted events by X coordinate
*/
static GeoEvent *geopolyEventMerge(GeoEvent *pLeft, GeoEvent *pRight){
  GeoEvent head, *pLast;
  head.pNext = 0;
  pLast = &head;
  while( pRight && pLeft ){
    if( pRight->x <= pLeft->x ){
      pLast->pNext = pRight;
      pLast = pRight;
      pRight = pRight->pNext;
    }else{
      pLast->pNext = pLeft;
      pLast = pLeft;
      pLeft = pLeft->pNext;
    }
  }
  pLast->pNext = pRight ? pRight : pLeft;
  return head.pNext;  
}

/*
** Sort an array of nEvent event objects into a list.
*/
static GeoEvent *geopolySortEventsByX(GeoEvent *aEvent, int nEvent){
  int mx = 0;
  int i, j;
  GeoEvent *p;
  GeoEvent *a[50];
  for(i=0; i<nEvent; i++){
    p = &aEvent[i];
    p->pNext = 0;
    for(j=0; j<mx && a[j]; j++){
      p = geopolyEventMerge(a[j], p);
      a[j] = 0;
    }
    a[j] = p;
    if( j>=mx ) mx = j+1;
  }
  p = 0;
  for(i=0; i<mx; i++){
    p = geopolyEventMerge(a[i], p);
  }
  return p;
}

/*
** Merge two lists of sorted segments by Y, and then by C.
*/
static GeoSegment *geopolySegmentMerge(GeoSegment *pLeft, GeoSegment *pRight){
  GeoSegment head, *pLast;
  head.pNext = 0;
  pLast = &head;
  while( pRight && pLeft ){
    double r = pRight->y - pLeft->y;
    if( r==0.0 ) r = pRight->C - pLeft->C;
    if( r<0.0 ){
      pLast->pNext = pRight;
      pLast = pRight;
      pRight = pRight->pNext;
    }else{
      pLast->pNext = pLeft;
      pLast = pLeft;
      pLeft = pLeft->pNext;
    }
  }
  pLast->pNext = pRight ? pRight : pLeft;
  return head.pNext;  
}

/*
** Sort a list of GeoSegments in order of increasing Y and in the event of
** a tie, increasing C (slope).
*/
static GeoSegment *geopolySortSegmentsByYAndC(GeoSegment *pList){
  int mx = 0;
  int i;
  GeoSegment *p;
  GeoSegment *a[50];
  while( pList ){
    p = pList;
    pList = pList->pNext;
    p->pNext = 0;
    for(i=0; i<mx && a[i]; i++){
      p = geopolySegmentMerge(a[i], p);
      a[i] = 0;
    }
    a[i] = p;
    if( i>=mx ) mx = i+1;
  }
  p = 0;
  for(i=0; i<mx; i++){
    p = geopolySegmentMerge(a[i], p);
  }
  return p;
}

/*
** Determine the overlap between two polygons
*/
static int geopolyOverlap(GeoPoly *p1, GeoPoly *p2){
  int nVertex = p1->nVertex + p2->nVertex + 2;
  GeoOverlap *p;
  int nByte;
  GeoEvent *pThisEvent;
  double rX;
  int rc = 0;
  int needSort = 0;
  GeoSegment *pActive = 0;
  GeoSegment *pSeg;
  unsigned char aOverlap[4];

  nByte = sizeof(GeoEvent)*nVertex*2 
           + sizeof(GeoSegment)*nVertex 
           + sizeof(GeoOverlap);
  p = sqlite3_malloc( nByte );
  if( p==0 ) return -1;
  p->aEvent = (GeoEvent*)&p[1];
  p->aSegment = (GeoSegment*)&p->aEvent[nVertex*2];
  p->nEvent = p->nSegment = 0;
  geopolyAddSegments(p, p1, 1);
  geopolyAddSegments(p, p2, 2);
  pThisEvent = geopolySortEventsByX(p->aEvent, p->nEvent);
  rX = pThisEvent->x==0.0 ? -1.0 : 0.0;
  memset(aOverlap, 0, sizeof(aOverlap));
  while( pThisEvent ){
    if( pThisEvent->x!=rX ){
      GeoSegment *pPrev = 0;
      int iMask = 0;
      GEODEBUG(("Distinct X: %g\n", pThisEvent->x));
      rX = pThisEvent->x;
      if( needSort ){
        GEODEBUG(("SORT\n"));
        pActive = geopolySortSegmentsByYAndC(pActive);
        needSort = 0;
      }
      for(pSeg=pActive; pSeg; pSeg=pSeg->pNext){
        if( pPrev ){
          if( pPrev->y!=pSeg->y ){
            GEODEBUG(("MASK: %d\n", iMask));
            aOverlap[iMask] = 1;
          }
        }
        iMask ^= pSeg->side;
        pPrev = pSeg;
      }
      pPrev = 0;
      for(pSeg=pActive; pSeg; pSeg=pSeg->pNext){
        double y = pSeg->C*rX + pSeg->B;
        GEODEBUG(("Segment %d.%d %g->%g\n", pSeg->side, pSeg->idx, pSeg->y, y));
        pSeg->y = y;
        if( pPrev ){
          if( pPrev->y>pSeg->y && pPrev->side!=pSeg->side ){
            rc = 1;
            GEODEBUG(("Crossing: %d.%d and %d.%d\n",
                    pPrev->side, pPrev->idx,
                    pSeg->side, pSeg->idx));
            goto geopolyOverlapDone;
          }else if( pPrev->y!=pSeg->y ){
            GEODEBUG(("MASK: %d\n", iMask));
            aOverlap[iMask] = 1;
          }
        }
        iMask ^= pSeg->side;
        pPrev = pSeg;
      }
    }
    GEODEBUG(("%s %d.%d C=%g B=%g\n",
      pThisEvent->eType ? "RM " : "ADD",
      pThisEvent->pSeg->side, pThisEvent->pSeg->idx,
      pThisEvent->pSeg->C,
      pThisEvent->pSeg->B));
    if( pThisEvent->eType==0 ){
      /* Add a segment */
      pSeg = pThisEvent->pSeg;
      pSeg->y = pSeg->y0;
      pSeg->pNext = pActive;
      pActive = pSeg;
      needSort = 1;
    }else{
      /* Remove a segment */
      if( pActive==pThisEvent->pSeg ){
        pActive = pActive->pNext;
      }else{
        for(pSeg=pActive; pSeg; pSeg=pSeg->pNext){
          if( pSeg->pNext==pThisEvent->pSeg ){
            pSeg->pNext = pSeg->pNext->pNext;
            break;
          }
        }
      }
    }
    pThisEvent = pThisEvent->pNext;
  }
  if( aOverlap[3]==0 ){
    rc = 0;
  }else if( aOverlap[1]!=0 && aOverlap[2]==0 ){
    rc = 3;
  }else if( aOverlap[1]==0 && aOverlap[2]!=0 ){
    rc = 2;
  }else if( aOverlap[1]==0 && aOverlap[2]==0 ){
    rc = 4;
  }else{
    rc = 1;
  }

geopolyOverlapDone:
  sqlite3_free(p);
  return rc;
}

/*
** SQL function:    geopoly_overlap(P1,P2)
**
** Determine whether or not P1 and P2 overlap. Return value:
**
**   0     The two polygons are disjoint
**   1     They overlap
**   2     P1 is completely contained within P2
**   3     P2 is completely contained within P1
**   4     P1 and P2 are the same polygon
**   NULL  Either P1 or P2 or both are not valid polygons
*/
static void geopolyOverlapFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  GeoPoly *p1 = geopolyFuncParam(context, argv[0], 0);
  GeoPoly *p2 = geopolyFuncParam(context, argv[1], 0);
  if( p1 && p2 ){
    int x = geopolyOverlap(p1, p2);
    if( x<0 ){
      sqlite3_result_error_nomem(context);
    }else{
      sqlite3_result_int(context, x);
    }
  }
  sqlite3_free(p1);
  sqlite3_free(p2);
}

/*
** Enable or disable debugging output
*/
static void geopolyDebugFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
#ifdef GEOPOLY_ENABLE_DEBUG
  geo_debug = sqlite3_value_int(argv[0]);
#endif
}

/* 
** This function is the implementation of both the xConnect and xCreate
** methods of the geopoly virtual table.
**
**   argv[0]   -> module name
**   argv[1]   -> database name
**   argv[2]   -> table name
**   argv[...] -> column names...
*/
static int geopolyInit(
  sqlite3 *db,                        /* Database connection */
  void *pAux,                         /* One of the RTREE_COORD_* constants */
  int argc, const char *const*argv,   /* Parameters to CREATE TABLE statement */
  sqlite3_vtab **ppVtab,              /* OUT: New virtual table */
  char **pzErr,                       /* OUT: Error message, if any */
  int isCreate                        /* True for xCreate, false for xConnect */
){
  int rc = SQLITE_OK;
  Rtree *pRtree;
  int nDb;              /* Length of string argv[1] */
  int nName;            /* Length of string argv[2] */
  sqlite3_str *pSql;
  char *zSql;
  int ii;

  sqlite3_vtab_config(db, SQLITE_VTAB_CONSTRAINT_SUPPORT, 1);

  /* Allocate the sqlite3_vtab structure */
  nDb = (int)strlen(argv[1]);
  nName = (int)strlen(argv[2]);
  pRtree = (Rtree *)sqlite3_malloc(sizeof(Rtree)+nDb+nName+2);
  if( !pRtree ){
    return SQLITE_NOMEM;
  }
  memset(pRtree, 0, sizeof(Rtree)+nDb+nName+2);
  pRtree->nBusy = 1;
  pRtree->base.pModule = &rtreeModule;
  pRtree->zDb = (char *)&pRtree[1];
  pRtree->zName = &pRtree->zDb[nDb+1];
  pRtree->eCoordType = RTREE_COORD_REAL32;
  pRtree->nDim = 2;
  pRtree->nDim2 = 4;
  memcpy(pRtree->zDb, argv[1], nDb);
  memcpy(pRtree->zName, argv[2], nName);


  /* Create/Connect to the underlying relational database schema. If
  ** that is successful, call sqlite3_declare_vtab() to configure
  ** the r-tree table schema.
  */
  pSql = sqlite3_str_new(db);
  sqlite3_str_appendf(pSql, "CREATE TABLE x(_shape");
  pRtree->nAux = 1;         /* Add one for _shape */
  pRtree->nAuxNotNull = 1;  /* The _shape column is always not-null */
  for(ii=3; ii<argc; ii++){
    pRtree->nAux++;
    sqlite3_str_appendf(pSql, ",%s", argv[ii]);
  }
  sqlite3_str_appendf(pSql, ");");
  zSql = sqlite3_str_finish(pSql);
  if( !zSql ){
    rc = SQLITE_NOMEM;
  }else if( SQLITE_OK!=(rc = sqlite3_declare_vtab(db, zSql)) ){
    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
  }
  sqlite3_free(zSql);
  if( rc ) goto geopolyInit_fail;
  pRtree->nBytesPerCell = 8 + pRtree->nDim2*4;

  /* Figure out the node size to use. */
  rc = getNodeSize(db, pRtree, isCreate, pzErr);
  if( rc ) goto geopolyInit_fail;
  rc = rtreeSqlInit(pRtree, db, argv[1], argv[2], isCreate);
  if( rc ){
    *pzErr = sqlite3_mprintf("%s", sqlite3_errmsg(db));
    goto geopolyInit_fail;
  }

  *ppVtab = (sqlite3_vtab *)pRtree;
  return SQLITE_OK;

geopolyInit_fail:
  if( rc==SQLITE_OK ) rc = SQLITE_ERROR;
  assert( *ppVtab==0 );
  assert( pRtree->nBusy==1 );
  rtreeRelease(pRtree);
  return rc;
}


/* 
** GEOPOLY virtual table module xCreate method.
*/
static int geopolyCreate(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  return geopolyInit(db, pAux, argc, argv, ppVtab, pzErr, 1);
}

/* 
** GEOPOLY virtual table module xConnect method.
*/
static int geopolyConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  return geopolyInit(db, pAux, argc, argv, ppVtab, pzErr, 0);
}


/* 
** GEOPOLY virtual table module xFilter method.
**
** Query plans:
**
**      1         rowid lookup
**      2         search for objects overlapping the same bounding box
**                that contains polygon argv[0]
**      3         search for objects overlapping the same bounding box
**                that contains polygon argv[0]
**      4         full table scan
*/
static int geopolyFilter(
  sqlite3_vtab_cursor *pVtabCursor,     /* The cursor to initialize */
  int idxNum,                           /* Query plan */
  const char *idxStr,                   /* Not Used */
  int argc, sqlite3_value **argv        /* Parameters to the query plan */
){
  Rtree *pRtree = (Rtree *)pVtabCursor->pVtab;
  RtreeCursor *pCsr = (RtreeCursor *)pVtabCursor;
  RtreeNode *pRoot = 0;
  int rc = SQLITE_OK;
  int iCell = 0;
  sqlite3_stmt *pStmt;

  rtreeReference(pRtree);

  /* Reset the cursor to the same state as rtreeOpen() leaves it in. */
  freeCursorConstraints(pCsr);
  sqlite3_free(pCsr->aPoint);
  pStmt = pCsr->pReadAux;
  memset(pCsr, 0, sizeof(RtreeCursor));
  pCsr->base.pVtab = (sqlite3_vtab*)pRtree;
  pCsr->pReadAux = pStmt;

  pCsr->iStrategy = idxNum;
  if( idxNum==1 ){
    /* Special case - lookup by rowid. */
    RtreeNode *pLeaf;        /* Leaf on which the required cell resides */
    RtreeSearchPoint *p;     /* Search point for the leaf */
    i64 iRowid = sqlite3_value_int64(argv[0]);
    i64 iNode = 0;
    rc = findLeafNode(pRtree, iRowid, &pLeaf, &iNode);
    if( rc==SQLITE_OK && pLeaf!=0 ){
      p = rtreeSearchPointNew(pCsr, RTREE_ZERO, 0);
      assert( p!=0 );  /* Always returns pCsr->sPoint */
      pCsr->aNode[0] = pLeaf;
      p->id = iNode;
      p->eWithin = PARTLY_WITHIN;
      rc = nodeRowidIndex(pRtree, pLeaf, iRowid, &iCell);
      p->iCell = (u8)iCell;
      RTREE_QUEUE_TRACE(pCsr, "PUSH-F1:");
    }else{
      pCsr->atEOF = 1;
    }
  }else{
    /* Normal case - r-tree scan. Set up the RtreeCursor.aConstraint array 
    ** with the configured constraints. 
    */
    rc = nodeAcquire(pRtree, 1, 0, &pRoot);
    if( rc==SQLITE_OK && idxNum<=3 ){
      RtreeCoord bbox[4];
      RtreeConstraint *p;
      assert( argc==1 );
      geopolyBBox(0, argv[0], bbox, &rc);
      if( rc ){
        goto geopoly_filter_end;
      }
      pCsr->aConstraint = p = sqlite3_malloc(sizeof(RtreeConstraint)*4);
      pCsr->nConstraint = 4;
      if( p==0 ){
        rc = SQLITE_NOMEM;
      }else{
        memset(pCsr->aConstraint, 0, sizeof(RtreeConstraint)*4);
        memset(pCsr->anQueue, 0, sizeof(u32)*(pRtree->iDepth + 1));
        if( idxNum==2 ){
          /* Overlap query */
          p->op = 'B';
          p->iCoord = 0;
          p->u.rValue = bbox[1].f;
          p++;
          p->op = 'D';
          p->iCoord = 1;
          p->u.rValue = bbox[0].f;
          p++;
          p->op = 'B';
          p->iCoord = 2;
          p->u.rValue = bbox[3].f;
          p++;
          p->op = 'D';
          p->iCoord = 3;
          p->u.rValue = bbox[2].f;
        }else{
          /* Within query */
          p->op = 'D';
          p->iCoord = 0;
          p->u.rValue = bbox[0].f;
          p++;
          p->op = 'B';
          p->iCoord = 1;
          p->u.rValue = bbox[1].f;
          p++;
          p->op = 'D';
          p->iCoord = 2;
          p->u.rValue = bbox[2].f;
          p++;
          p->op = 'B';
          p->iCoord = 3;
          p->u.rValue = bbox[3].f;
        }
      }
    }
    if( rc==SQLITE_OK ){
      RtreeSearchPoint *pNew;
      pNew = rtreeSearchPointNew(pCsr, RTREE_ZERO, (u8)(pRtree->iDepth+1));
      if( pNew==0 ){
        rc = SQLITE_NOMEM;
        goto geopoly_filter_end;
      }
      pNew->id = 1;
      pNew->iCell = 0;
      pNew->eWithin = PARTLY_WITHIN;
      assert( pCsr->bPoint==1 );
      pCsr->aNode[0] = pRoot;
      pRoot = 0;
      RTREE_QUEUE_TRACE(pCsr, "PUSH-Fm:");
      rc = rtreeStepToLeaf(pCsr);
    }
  }

geopoly_filter_end:
  nodeRelease(pRtree, pRoot);
  rtreeRelease(pRtree);
  return rc;
}

/*
** Rtree virtual table module xBestIndex method. There are three
** table scan strategies to choose from (in order from most to 
** least desirable):
**
**   idxNum     idxStr        Strategy
**   ------------------------------------------------
**     1        "rowid"       Direct lookup by rowid.
**     2        "rtree"       R-tree overlap query using geopoly_overlap()
**     3        "rtree"       R-tree within query using geopoly_within()
**     4        "fullscan"    full-table scan.
**   ------------------------------------------------
*/
static int geopolyBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
  int ii;
  int iRowidTerm = -1;
  int iFuncTerm = -1;
  int idxNum = 0;

  for(ii=0; ii<pIdxInfo->nConstraint; ii++){
    struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[ii];
    if( !p->usable ) continue;
    if( p->iColumn<0 && p->op==SQLITE_INDEX_CONSTRAINT_EQ  ){
      iRowidTerm = ii;
      break;
    }
    if( p->iColumn==0 && p->op>=SQLITE_INDEX_CONSTRAINT_FUNCTION ){
      /* p->op==SQLITE_INDEX_CONSTRAINT_FUNCTION for geopoly_overlap()
      ** p->op==(SQLITE_INDEX_CONTRAINT_FUNCTION+1) for geopoly_within().
      ** See geopolyFindFunction() */
      iFuncTerm = ii;
      idxNum = p->op - SQLITE_INDEX_CONSTRAINT_FUNCTION + 2;
    }
  }

  if( iRowidTerm>=0 ){
    pIdxInfo->idxNum = 1;
    pIdxInfo->idxStr = "rowid";
    pIdxInfo->aConstraintUsage[iRowidTerm].argvIndex = 1;
    pIdxInfo->aConstraintUsage[iRowidTerm].omit = 1;
    pIdxInfo->estimatedCost = 30.0;
    pIdxInfo->estimatedRows = 1;
    pIdxInfo->idxFlags = SQLITE_INDEX_SCAN_UNIQUE;
    return SQLITE_OK;
  }
  if( iFuncTerm>=0 ){
    pIdxInfo->idxNum = idxNum;
    pIdxInfo->idxStr = "rtree";
    pIdxInfo->aConstraintUsage[iFuncTerm].argvIndex = 1;
    pIdxInfo->aConstraintUsage[iFuncTerm].omit = 0;
    pIdxInfo->estimatedCost = 300.0;
    pIdxInfo->estimatedRows = 10;
    return SQLITE_OK;
  }
  pIdxInfo->idxNum = 4;
  pIdxInfo->idxStr = "fullscan";
  pIdxInfo->estimatedCost = 3000000.0;
  pIdxInfo->estimatedRows = 100000;
  return SQLITE_OK;
}


/* 
** GEOPOLY virtual table module xColumn method.
*/
static int geopolyColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
  Rtree *pRtree = (Rtree *)cur->pVtab;
  RtreeCursor *pCsr = (RtreeCursor *)cur;
  RtreeSearchPoint *p = rtreeSearchPointFirst(pCsr);
  int rc = SQLITE_OK;
  RtreeNode *pNode = rtreeNodeOfFirstSearchPoint(pCsr, &rc);

  if( rc ) return rc;
  if( p==0 ) return SQLITE_OK;
  if( i==0 && sqlite3_vtab_nochange(ctx) ) return SQLITE_OK;
  if( i<=pRtree->nAux ){
    if( !pCsr->bAuxValid ){
      if( pCsr->pReadAux==0 ){
        rc = sqlite3_prepare_v3(pRtree->db, pRtree->zReadAuxSql, -1, 0,
                                &pCsr->pReadAux, 0);
        if( rc ) return rc;
      }
      sqlite3_bind_int64(pCsr->pReadAux, 1, 
          nodeGetRowid(pRtree, pNode, p->iCell));
      rc = sqlite3_step(pCsr->pReadAux);
      if( rc==SQLITE_ROW ){
        pCsr->bAuxValid = 1;
      }else{
        sqlite3_reset(pCsr->pReadAux);
        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
        return rc;
      }
    }
    sqlite3_result_value(ctx, sqlite3_column_value(pCsr->pReadAux, i+2));
  }
  return SQLITE_OK;
}


/*
** The xUpdate method for GEOPOLY module virtual tables.
**
** For DELETE:
**
**     argv[0] = the rowid to be deleted
**
** For INSERT:
**
**     argv[0] = SQL NULL
**     argv[1] = rowid to insert, or an SQL NULL to select automatically
**     argv[2] = _shape column
**     argv[3] = first application-defined column....
**
** For UPDATE:
**
**     argv[0] = rowid to modify.  Never NULL
**     argv[1] = rowid after the change.  Never NULL
**     argv[2] = new value for _shape
**     argv[3] = new value for first application-defined column....
*/
static int geopolyUpdate(
  sqlite3_vtab *pVtab, 
  int nData, 
  sqlite3_value **aData, 
  sqlite_int64 *pRowid
){
  Rtree *pRtree = (Rtree *)pVtab;
  int rc = SQLITE_OK;
  RtreeCell cell;                 /* New cell to insert if nData>1 */
  i64 oldRowid;                   /* The old rowid */
  int oldRowidValid;              /* True if oldRowid is valid */
  i64 newRowid;                   /* The new rowid */
  int newRowidValid;              /* True if newRowid is valid */
  int coordChange = 0;            /* Change in coordinates */

  if( pRtree->nNodeRef ){
    /* Unable to write to the btree while another cursor is reading from it,
    ** since the write might do a rebalance which would disrupt the read
    ** cursor. */
    return SQLITE_LOCKED_VTAB;
  }
  rtreeReference(pRtree);
  assert(nData>=1);

  oldRowidValid = sqlite3_value_type(aData[0])!=SQLITE_NULL;;
  oldRowid = oldRowidValid ? sqlite3_value_int64(aData[0]) : 0;
  newRowidValid = nData>1 && sqlite3_value_type(aData[1])!=SQLITE_NULL;
  newRowid = newRowidValid ? sqlite3_value_int64(aData[1]) : 0;
  cell.iRowid = newRowid;

  if( nData>1                                 /* not a DELETE */
   && (!oldRowidValid                         /* INSERT */
        || !sqlite3_value_nochange(aData[2])  /* UPDATE _shape */
        || oldRowid!=newRowid)                /* Rowid change */
  ){
    geopolyBBox(0, aData[2], cell.aCoord, &rc);
    if( rc ){
      if( rc==SQLITE_ERROR ){
        pVtab->zErrMsg =
          sqlite3_mprintf("_shape does not contain a valid polygon");
      }
      goto geopoly_update_end;
    }
    coordChange = 1;

    /* If a rowid value was supplied, check if it is already present in 
    ** the table. If so, the constraint has failed. */
    if( newRowidValid && (!oldRowidValid || oldRowid!=newRowid) ){
      int steprc;
      sqlite3_bind_int64(pRtree->pReadRowid, 1, cell.iRowid);
      steprc = sqlite3_step(pRtree->pReadRowid);
      rc = sqlite3_reset(pRtree->pReadRowid);
      if( SQLITE_ROW==steprc ){
        if( sqlite3_vtab_on_conflict(pRtree->db)==SQLITE_REPLACE ){
          rc = rtreeDeleteRowid(pRtree, cell.iRowid);
        }else{
          rc = rtreeConstraintError(pRtree, 0);
        }
      }
    }
  }

  /* If aData[0] is not an SQL NULL value, it is the rowid of a
  ** record to delete from the r-tree table. The following block does
  ** just that.
  */
  if( rc==SQLITE_OK && (nData==1 || (coordChange && oldRowidValid)) ){
    rc = rtreeDeleteRowid(pRtree, oldRowid);
  }

  /* If the aData[] array contains more than one element, elements
  ** (aData[2]..aData[argc-1]) contain a new record to insert into
  ** the r-tree structure.
  */
  if( rc==SQLITE_OK && nData>1 && coordChange ){
    /* Insert the new record into the r-tree */
    RtreeNode *pLeaf = 0;
    if( !newRowidValid ){
      rc = rtreeNewRowid(pRtree, &cell.iRowid);
    }
    *pRowid = cell.iRowid;
    if( rc==SQLITE_OK ){
      rc = ChooseLeaf(pRtree, &cell, 0, &pLeaf);
    }
    if( rc==SQLITE_OK ){
      int rc2;
      pRtree->iReinsertHeight = -1;
      rc = rtreeInsertCell(pRtree, pLeaf, &cell, 0);
      rc2 = nodeRelease(pRtree, pLeaf);
      if( rc==SQLITE_OK ){
        rc = rc2;
      }
    }
  }

  /* Change the data */
  if( rc==SQLITE_OK ){
    sqlite3_stmt *pUp = pRtree->pWriteAux;
    int jj;
    int nChange = 0;
    sqlite3_bind_int64(pUp, 1, cell.iRowid);
    assert( pRtree->nAux>=1 );
    if( sqlite3_value_nochange(aData[2]) ){
      sqlite3_bind_null(pUp, 2);
    }else{
      sqlite3_bind_value(pUp, 2, aData[2]);
      nChange = 1;
    }
    for(jj=1; jj<pRtree->nAux; jj++){
      nChange++;
      sqlite3_bind_value(pUp, jj+2, aData[jj+2]);
    }
    if( nChange ){
      sqlite3_step(pUp);
      rc = sqlite3_reset(pUp);
    }
  }

geopoly_update_end:
  rtreeRelease(pRtree);
  return rc;
}

/*
** Report that geopoly_overlap() is an overloaded function suitable
** for use in xBestIndex.
*/
static int geopolyFindFunction(
  sqlite3_vtab *pVtab,
  int nArg,
  const char *zName,
  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
  void **ppArg
){
  if( sqlite3_stricmp(zName, "geopoly_overlap")==0 ){
    *pxFunc = geopolyOverlapFunc;
    *ppArg = 0;
    return SQLITE_INDEX_CONSTRAINT_FUNCTION;
  }
  if( sqlite3_stricmp(zName, "geopoly_within")==0 ){
    *pxFunc = geopolyWithinFunc;
    *ppArg = 0;
    return SQLITE_INDEX_CONSTRAINT_FUNCTION+1;
  }
  return 0;
}


static sqlite3_module geopolyModule = {
  2,                          /* iVersion */
  geopolyCreate,              /* xCreate - create a table */
  geopolyConnect,             /* xConnect - connect to an existing table */
  geopolyBestIndex,           /* xBestIndex - Determine search strategy */
  rtreeDisconnect,            /* xDisconnect - Disconnect from a table */
  rtreeDestroy,               /* xDestroy - Drop a table */
  rtreeOpen,                  /* xOpen - open a cursor */
  rtreeClose,                 /* xClose - close a cursor */
  geopolyFilter,              /* xFilter - configure scan constraints */
  rtreeNext,                  /* xNext - advance a cursor */
  rtreeEof,                   /* xEof */
  geopolyColumn,              /* xColumn - read data */
  rtreeRowid,                 /* xRowid - read data */
  geopolyUpdate,              /* xUpdate - write data */
  rtreeBeginTransaction,      /* xBegin - begin transaction */
  rtreeEndTransaction,        /* xSync - sync transaction */
  rtreeEndTransaction,        /* xCommit - commit transaction */
  rtreeEndTransaction,        /* xRollback - rollback transaction */
  geopolyFindFunction,        /* xFindFunction - function overloading */
  rtreeRename,                /* xRename - rename the table */
  rtreeSavepoint,             /* xSavepoint */
  0,                          /* xRelease */
  0,                          /* xRollbackTo */
};

static int sqlite3_geopoly_init(sqlite3 *db){
  int rc = SQLITE_OK;
  static const struct {
    void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
    int nArg;
    const char *zName;
  } aFunc[] = {
     { geopolyAreaFunc,          1,    "geopoly_area"             },
     { geopolyBlobFunc,          1,    "geopoly_blob"             },
     { geopolyJsonFunc,          1,    "geopoly_json"             },
     { geopolySvgFunc,          -1,    "geopoly_svg"              },
     { geopolyWithinFunc,        2,    "geopoly_within"           },
     { geopolyContainsPointFunc, 3,    "geopoly_contains_point"   },
     { geopolyOverlapFunc,       2,    "geopoly_overlap"          },
     { geopolyDebugFunc,         1,    "geopoly_debug"            },
     { geopolyBBoxFunc,          1,    "geopoly_bbox"             },
     { geopolyXformFunc,         7,    "geopoly_xform"            },
  };
  static const struct {
    void (*xStep)(sqlite3_context*,int,sqlite3_value**);
    void (*xFinal)(sqlite3_context*);
    const char *zName;
  } aAgg[] = {
     { geopolyBBoxStep, geopolyBBoxFinal, "geopoly_group_bbox"    },
  };
  int i;
  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zName, aFunc[i].nArg,
                                 SQLITE_UTF8, 0,
                                 aFunc[i].xFunc, 0, 0);
  }
  for(i=0; i<sizeof(aAgg)/sizeof(aAgg[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aAgg[i].zName, 1, SQLITE_UTF8, 0,
                                 0, aAgg[i].xStep, aAgg[i].xFinal);
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module_v2(db, "geopoly", &geopolyModule, 0, 0);
  }
  return rc;
}

/************** End of geopoly.c *********************************************/
/************** Continuing where we left off in rtree.c **********************/
#endif

/*
** Register the r-tree module with database handle db. This creates the
** virtual table module "rtree" and the debugging/analysis scalar 
** function "rtreenode".
*/
SQLITE_PRIVATE int sqlite3RtreeInit(sqlite3 *db){

#endif
    rc = sqlite3_create_module_v2(db, "rtree", &rtreeModule, c, 0);
  }
  if( rc==SQLITE_OK ){
    void *c = (void *)RTREE_COORD_INT32;
    rc = sqlite3_create_module_v2(db, "rtree_i32", &rtreeModule, c, 0);
  }
#ifdef SQLITE_ENABLE_GEOPOLY
  if( rc==SQLITE_OK ){
    rc = sqlite3_geopoly_init(db);
  }
#endif

  return rc;
}

/*
** This routine deletes the RtreeGeomCallback object that was attached
** one of the SQL functions create by sqlite3_rtree_geometry_callback()