Fossil

  );
  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isChnged = db_column_int(&q,2);
    int isNew = db_column_int(&q,3)==0;
    int isRenamed = db_column_int(&q,4);
    char *zFullName = mprintf("%s/%s", g.zLocalRoot, zPathname);
    blob_append(report, zPrefix, nPrefix);
    if( isDeleted ){
      blob_appendf(report, "DELETED    %s\n", zPathname);
    }else if( !file_isfile(zFullName) ){
      if( access(zFullName, 0)==0 ){
        blob_appendf(report, "NOT_A_FILE %s\n", zPathname);
        if( missingIsFatal ){
................................................................................
  );
  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isNew = db_column_int(&q,2)==0;
    int chnged = db_column_int(&q,3);
    int renamed = db_column_int(&q,4);
    char *zFullName = mprintf("%s/%s", g.zLocalRoot, zPathname);
    if( isBrief ){
      printf("%s\n", zPathname);
    }else if( isNew ){
      printf("ADDED      %s\n", zPathname);
    }else if( isDeleted ){
      printf("DELETED    %s\n", zPathname);
    }else if( !file_isfile(zFullName) ){

  );
  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isChnged = db_column_int(&q,2);
    int isNew = db_column_int(&q,3)==0;
    int isRenamed = db_column_int(&q,4);
    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    blob_append(report, zPrefix, nPrefix);
    if( isDeleted ){
      blob_appendf(report, "DELETED    %s\n", zPathname);
    }else if( !file_isfile(zFullName) ){
      if( access(zFullName, 0)==0 ){
        blob_appendf(report, "NOT_A_FILE %s\n", zPathname);
        if( missingIsFatal ){
................................................................................
  );
  while( db_step(&q)==SQLITE_ROW ){
    const char *zPathname = db_column_text(&q,0);
    int isDeleted = db_column_int(&q, 1);
    int isNew = db_column_int(&q,2)==0;
    int chnged = db_column_int(&q,3);
    int renamed = db_column_int(&q,4);
    char *zFullName = mprintf("%s%s", g.zLocalRoot, zPathname);
    if( isBrief ){
      printf("%s\n", zPathname);
    }else if( isNew ){
      printf("ADDED      %s\n", zPathname);
    }else if( isDeleted ){
      printf("DELETED    %s\n", zPathname);
    }else if( !file_isfile(zFullName) ){

    return;
  }
rep_not_found:
  if( (bFlags & OPEN_OK_NOT_FOUND)==0 ){
    fossil_fatal("use --repository or -R to specify the repository database");
  }
}












/*
** Verify that the repository schema is correct.  If it is not correct,
** issue a fatal error and die.
*/
void db_verify_schema(void){
  if( db_exists("SELECT 1 FROM config"

    return;
  }
rep_not_found:
  if( (bFlags & OPEN_OK_NOT_FOUND)==0 ){
    fossil_fatal("use --repository or -R to specify the repository database");
  }
}

/*
** Return the name of the database "localdb", "configdb", or "repository".
*/
const char *db_name(const char *zDb){
  assert( strcmp(zDb,"localdb")==0
       || strcmp(zDb,"configdb")==0
       || strcmp(zDb,"repository")==0 );
  if( strcmp(zDb, g.zMainDbType)==0 ) zDb = "main";
  return zDb;
}

/*
** Verify that the repository schema is correct.  If it is not correct,
** issue a fatal error and die.
*/
void db_verify_schema(void){
  if( db_exists("SELECT 1 FROM config"

     stashid
  );
  while( db_step(&q)==SQLITE_ROW ){
    int deleted = db_column_int(&q, 0);
    int rid = db_column_int(&q, 2);
    const char *zName = db_column_text(&q, 3);
    const char *zOrig = db_column_text(&q, 4);
    char *zPath = mprintf("%s/%s", g.zLocalRoot, zName);
    Blob content;

    db_bind_int(&ins, ":rid", rid);
    db_bind_int(&ins, ":isadd", rid==0);
    db_bind_int(&ins, ":isrm", deleted);
#ifdef _WIN32
    db_bind_int(&ins, ":isexe", db_column_int(&q, 2));
................................................................................
**
** If the "-m" or "--comment" command-line option is present, gather
** its argument as the stash comment.
**
** If files are named on the command-line, then only stash the named
** files.
*/
static void stash_create(void){
  const char *zComment;              /* Comment to add to the stash */
  int stashid;                       /* ID of the new stash */
  int vid;                           /* Current checkout */

  zComment = find_option("comment", "m", 1);
  verify_all_options();
  stashid = db_lget_int("stash-next", 1);
................................................................................
  if( g.argc>3 ){
    int i;
    for(i=3; i<g.argc; i++){
      stash_add_file_or_dir(stashid, vid, g.argv[i]);
    }
  }else{
    stash_add_file_or_dir(stashid, vid, ".");
  } 

}

/*
** Apply a stash to the current check-out.
*/
static void stash_apply(int stashid, int nConflict){
  Stmt q;
................................................................................
     stashid
  );
  while( db_step(&q)==SQLITE_ROW ){
    int rid = db_column_int(&q, 0);
    int isRemoved = db_column_int(&q, 1);
    const char *zOrig = db_column_text(&q, 3);
    const char *zNew = db_column_text(&q, 4);
    char *zOPath = mprintf("%s/%s", g.zLocalRoot, zOrig);
    char *zNPath = mprintf("%s/%s", g.zLocalRoot, zNew);
    undo_save(zNPath);
    Blob delta;
    if( rid==0 ){
      db_ephemeral_blob(&q, 5, &delta);
      blob_write_to_file(&delta, zNPath);
      printf("ADD %s\n", zNew);
    }else if( isRemoved ){
      printf("DELETE %s\n", zOrig);
................................................................................
        blob_reset(&out);
      }
      blob_reset(&a);
      blob_reset(&b);
      blob_reset(&delta);
    }
    if( strcmp(zOrig,zNew)!=0 ){
      undo_save(zOPath);
      unlink(zOPath);
    }
  }
  db_finalize(&q);
  if( nConflict ){
    printf("WARNING: merge conflicts - see messages above for details.\n");
  }
................................................................................

/*
** COMMAND: stash
**
** Usage: %fossil COMMAND ARGS...
**
**    fossil stash
**    fossil stash save [-m COMMENT] [FILES...]
**
**         Save the current changes in the working tree as a new stash.
**         Then revert the changes back to the last check-in.  If FILES
**         are listed, then only stash and revert the named files.  The
**         "save" verb can be omitted if and only if there are no other
**         arguments.
**
................................................................................
**         List all changes sets currently stashed.
**
**    fossil stash pop
**
**         Apply the most recently create stash to the current working
**         check-out.  Then delete that stash.  This is equivalent to
**         doing an "apply" and a "drop" against the most recent stash.

**
**    fossil stash apply STASHID
**
**         Apply the identified stash to the current working check-out.
**         But unlike "pop", keep the stash so that it can be used again.



**
**    fossil stash goto STASHID
**
**         Update to the baseline checkout for STASHID then apply the
**         changes of STASHID.  Keep STASHID so that it can be reused

**
**    fossil drop STASHID
**
**         Forget everything about STASHID.
**
**    fossil stash snapshot [-m COMMENT] [FILES...]
**
**         Save the current changes in the working tress as a new stash
**         but, unlike "save", do not revert those changes.
*/
void stash_cmd(void){
  const char *zDb = "localdb";
  const char *zCmd;
  int nCmd;


  undo_capture_command_line();
  db_must_be_within_tree();
  db_begin_transaction();
  if( strcmp(g.zMainDbType, zDb)==0 ) zDb = "main";
  db_multi_exec(zStashInit, zDb, zDb);
  if( g.argc<=2 ){
    zCmd = "save";
  }else{
    zCmd = g.argv[2];
  }
  nCmd = strlen(zCmd);
................................................................................
      }
    }
    db_finalize(&q);
    if( n==0 ) printf("empty stash\n");
  }else
  if( memcmp(zCmd, "drop", nCmd)==0 ){
    if( g.argc>4 ) usage("stash apply STASHID");
    int stashid = stash_get_id(g.argc==4 ? g.argv[3] : 0);


    stash_drop(stashid);

  }else
  if( memcmp(zCmd, "pop", nCmd)==0 ){
    if( g.argc>3 ) usage("stash pop");
    int stashid = stash_get_id(0);
    undo_begin();
    stash_apply(stashid, 0);

    undo_finish();
    stash_drop(stashid);
  }else
  if( memcmp(zCmd, "apply", nCmd)==0 ){
    if( g.argc>4 ) usage("stash apply STASHID");
    int stashid = stash_get_id(g.argc==4 ? g.argv[3] : 0);
    undo_begin();
    stash_apply(stashid, 0);
    undo_finish();
  }else
  if( memcmp(zCmd, "goto", nCmd)==0 ){



    if( g.argc>4 ) usage("stash apply STASHID");
    int stashid = stash_get_id(g.argc==4 ? g.argv[3] : 0);
    undo_begin();
    update_to(db_int(0, "SELECT vid FROM stash WHERE stashid=%d", stashid));

    stash_apply(stashid, 0);



    undo_finish();
  }else
  {
    usage("apply|drop|goto|list|pop|save|snapshot ARGS...");
  }
  db_end_transaction(0);
}

     stashid
  );
  while( db_step(&q)==SQLITE_ROW ){
    int deleted = db_column_int(&q, 0);
    int rid = db_column_int(&q, 2);
    const char *zName = db_column_text(&q, 3);
    const char *zOrig = db_column_text(&q, 4);
    char *zPath = mprintf("%s%s", g.zLocalRoot, zName);
    Blob content;

    db_bind_int(&ins, ":rid", rid);
    db_bind_int(&ins, ":isadd", rid==0);
    db_bind_int(&ins, ":isrm", deleted);
#ifdef _WIN32
    db_bind_int(&ins, ":isexe", db_column_int(&q, 2));
................................................................................
**
** If the "-m" or "--comment" command-line option is present, gather
** its argument as the stash comment.
**
** If files are named on the command-line, then only stash the named
** files.
*/
static int stash_create(void){
  const char *zComment;              /* Comment to add to the stash */
  int stashid;                       /* ID of the new stash */
  int vid;                           /* Current checkout */

  zComment = find_option("comment", "m", 1);
  verify_all_options();
  stashid = db_lget_int("stash-next", 1);
................................................................................
  if( g.argc>3 ){
    int i;
    for(i=3; i<g.argc; i++){
      stash_add_file_or_dir(stashid, vid, g.argv[i]);
    }
  }else{
    stash_add_file_or_dir(stashid, vid, ".");
  }
  return stashid;
}

/*
** Apply a stash to the current check-out.
*/
static void stash_apply(int stashid, int nConflict){
  Stmt q;
................................................................................
     stashid
  );
  while( db_step(&q)==SQLITE_ROW ){
    int rid = db_column_int(&q, 0);
    int isRemoved = db_column_int(&q, 1);
    const char *zOrig = db_column_text(&q, 3);
    const char *zNew = db_column_text(&q, 4);
    char *zOPath = mprintf("%s%s", g.zLocalRoot, zOrig);
    char *zNPath = mprintf("%s%s", g.zLocalRoot, zNew);
    undo_save(zNew);
    Blob delta;
    if( rid==0 ){
      db_ephemeral_blob(&q, 5, &delta);
      blob_write_to_file(&delta, zNPath);
      printf("ADD %s\n", zNew);
    }else if( isRemoved ){
      printf("DELETE %s\n", zOrig);
................................................................................
        blob_reset(&out);
      }
      blob_reset(&a);
      blob_reset(&b);
      blob_reset(&delta);
    }
    if( strcmp(zOrig,zNew)!=0 ){
      undo_save(zOrig);
      unlink(zOPath);
    }
  }
  db_finalize(&q);
  if( nConflict ){
    printf("WARNING: merge conflicts - see messages above for details.\n");
  }
................................................................................

/*
** COMMAND: stash
**
** Usage: %fossil COMMAND ARGS...
**
**    fossil stash
**    fossil stash save ?-m COMMENT? ?FILES...?
**
**         Save the current changes in the working tree as a new stash.
**         Then revert the changes back to the last check-in.  If FILES
**         are listed, then only stash and revert the named files.  The
**         "save" verb can be omitted if and only if there are no other
**         arguments.
**
................................................................................
**         List all changes sets currently stashed.
**
**    fossil stash pop
**
**         Apply the most recently create stash to the current working
**         check-out.  Then delete that stash.  This is equivalent to
**         doing an "apply" and a "drop" against the most recent stash.
**         This command is undoable.
**
**    fossil stash apply ?STASHID?
**
**         Apply the identified stash to the current working check-out.

**         If no STASHID is specifed, use the most recent stash.  Unlike
**         the "pop" command, the stash is retained so that it can be used
**         again.  This command is undoable.
**
**    fossil stash goto ?STASHID?
**
**         Update to the baseline checkout for STASHID then apply the
**         changes of STASHID.  Keep STASHID so that it can be reused
**         This command is undoable.
**
**    fossil drop ?STASHID?
**
**         Forget everything about STASHID.  This command is undoable.
**
**    fossil stash snapshot ?-m COMMENT? ?FILES...?
**
**         Save the current changes in the working tress as a new stash
**         but, unlike "save", do not revert those changes.
*/
void stash_cmd(void){
  const char *zDb;
  const char *zCmd;
  int nCmd;
  int stashid;

  undo_capture_command_line();
  db_must_be_within_tree();
  db_begin_transaction();
  zDb = db_name("localdb");
  db_multi_exec(zStashInit, zDb, zDb);
  if( g.argc<=2 ){
    zCmd = "save";
  }else{
    zCmd = g.argv[2];
  }
  nCmd = strlen(zCmd);
................................................................................
      }
    }
    db_finalize(&q);
    if( n==0 ) printf("empty stash\n");
  }else
  if( memcmp(zCmd, "drop", nCmd)==0 ){
    if( g.argc>4 ) usage("stash apply STASHID");
    stashid = stash_get_id(g.argc==4 ? g.argv[3] : 0);
    undo_begin();
    undo_save_stash(stashid);
    stash_drop(stashid);
    undo_finish();
  }else
  if( memcmp(zCmd, "pop", nCmd)==0 ){
    if( g.argc>3 ) usage("stash pop");
    stashid = stash_get_id(0);
    undo_begin();
    stash_apply(stashid, 0);
    undo_save_stash(stashid);
    undo_finish();
    stash_drop(stashid);
  }else
  if( memcmp(zCmd, "apply", nCmd)==0 ){
    if( g.argc>4 ) usage("stash apply STASHID");
    stashid = stash_get_id(g.argc==4 ? g.argv[3] : 0);
    undo_begin();
    stash_apply(stashid, 0);
    undo_finish();
  }else
  if( memcmp(zCmd, "goto", nCmd)==0 ){
    int nConflict;
    int vid;

    if( g.argc>4 ) usage("stash apply STASHID");
    stashid = stash_get_id(g.argc==4 ? g.argv[3] : 0);
    undo_begin();
    vid = db_int(0, "SELECT vid FROM stash WHERE stashid=%d", stashid);
    nConflict = update_to(vid);
    stash_apply(stashid, nConflict);
    db_multi_exec("UPDATE vfile SET mtime=0 WHERE pathname IN "
                  "(SELECT origname FROM stashfile WHERE stashid=%d)",
                  stashid);
    undo_finish();
  }else
  {
    usage("apply|drop|goto|list|pop|save|snapshot ARGS...");
  }
  db_end_transaction(0);
}

  @ <tr><th>Fossil&nbsp;Version:</th><td>
  @ %h(MANIFEST_DATE) %h(MANIFEST_VERSION) (%h(COMPILER_NAME))
  @ </td></tr>
  @ <tr><th>SQLite&nbsp;Version:</th><td>
  sqlite3_snprintf(sizeof(zBuf), zBuf, "%.19s [%.10s] (%s)",
                   SQLITE_SOURCE_ID, &SQLITE_SOURCE_ID[20], SQLITE_VERSION);
  zDb = "repository";
  if( strcmp(g.zMainDbType, zDb)==0 ) zDb = "main";
  @ %s(zBuf)
  @ </td></tr>
  @ <tr><th>Database&nbsp;Stats:</th><td>
  @ %d(db_int(0, "PRAGMA %s.page_count", zDb)) pages,
  @ %d(db_int(0, "PRAGMA %s.page_size", zDb)) bytes/page,
  @ %d(db_int(0, "PRAGMA %s.freelist_count", zDb)) free pages,
  @ %s(db_text(0, "PRAGMA %s.encoding", zDb)),
  @ %s(db_text(0, "PRAGMA %s.journal_mode", zDb)) mode
  @ </td></tr>

  @ </table>
  style_footer();
}

  @ <tr><th>Fossil&nbsp;Version:</th><td>
  @ %h(MANIFEST_DATE) %h(MANIFEST_VERSION) (%h(COMPILER_NAME))
  @ </td></tr>
  @ <tr><th>SQLite&nbsp;Version:</th><td>
  sqlite3_snprintf(sizeof(zBuf), zBuf, "%.19s [%.10s] (%s)",
                   SQLITE_SOURCE_ID, &SQLITE_SOURCE_ID[20], SQLITE_VERSION);
  zDb = db_name("repository");

  @ %s(zBuf)
  @ </td></tr>
  @ <tr><th>Database&nbsp;Stats:</th><td>
  @ %d(db_int(0, "PRAGMA %s.page_count", zDb)) pages,
  @ %d(db_int(0, "PRAGMA %s.page_size", zDb)) bytes/page,
  @ %d(db_int(0, "PRAGMA %s.freelist_count", zDb)) free pages,
  @ %s(db_text(0, "PRAGMA %s.encoding", zDb)),
  @ %s(db_text(0, "PRAGMA %s.journal_mode", zDb)) mode
  @ </td></tr>

  @ </table>
  style_footer();
}

/*
** Undo or redo all undoable or redoable changes.
*/
static void undo_all(int redoFlag){
  int ucid;
  int ncid;

  undo_all_filesystem(redoFlag);
  db_multi_exec(
    "CREATE TEMP TABLE undo_vfile_2 AS SELECT * FROM vfile;"
    "DELETE FROM vfile;"
    "INSERT INTO vfile SELECT * FROM undo_vfile;"
    "DELETE FROM undo_vfile;"
    "INSERT INTO undo_vfile SELECT * FROM undo_vfile_2;"
................................................................................
    "CREATE TEMP TABLE undo_vmerge_2 AS SELECT * FROM vmerge;"
    "DELETE FROM vmerge;"
    "INSERT INTO vmerge SELECT * FROM undo_vmerge;"
    "DELETE FROM undo_vmerge;"
    "INSERT INTO undo_vmerge SELECT * FROM undo_vmerge_2;"
    "DROP TABLE undo_vmerge_2;"
  );














  ncid = db_lget_int("undo_checkout", 0);
  ucid = db_lget_int("checkout", 0);
  db_lset_int("undo_checkout", ucid);
  db_lset_int("checkout", ncid);
}

/*
................................................................................
** Reset the undo memory.
*/
void undo_reset(void){
  static const char zSql[] =
    @ DROP TABLE IF EXISTS undo;
    @ DROP TABLE IF EXISTS undo_vfile;
    @ DROP TABLE IF EXISTS undo_vmerge;


    ;
  db_multi_exec(zSql);
  db_lset_int("undo_available", 0);
  db_lset_int("undo_checkout", 0);
}

/*
................................................................................
}

/*
** Begin capturing a snapshot that can be undone.
*/
void undo_begin(void){
  int cid;
  const char *zDb = "localdb";
  static const char zSql[] = 
    @ CREATE TABLE %s.undo(
    @   pathname TEXT UNIQUE,             -- Name of the file
    @   redoflag BOOLEAN,                 -- 0 for undoable.  1 for redoable
    @   existsflag BOOLEAN,               -- True if the file exists
    @   content BLOB                      -- Saved content
    @ );
    @ CREATE TABLE %s.undo_vfile AS SELECT * FROM vfile;
    @ CREATE TABLE %s.undo_vmerge AS SELECT * FROM vmerge;
  ;
  if( undoDisable ) return;
  undo_reset();
  if( strcmp(g.zMainDbType,zDb)==0 ) zDb = "main";
  db_multi_exec(zSql, zDb, zDb, zDb, zDb);
  cid = db_lget_int("checkout", 0);
  db_lset_int("undo_checkout", cid);
  db_lset_int("undo_available", 1);
  db_lset("undo_cmdline", undoCmd);
  undoActive = 1;
}

................................................................................
void undo_save(const char *zPathname){
  char *zFullname;
  Blob content;
  int existsFlag;
  Stmt q;

  if( !undoActive ) return;
  zFullname = mprintf("%s/%s", g.zLocalRoot, zPathname);
  existsFlag = file_size(zFullname)>=0;
  db_prepare(&q,
    "INSERT OR IGNORE INTO undo(pathname,redoflag,existsflag,content)"
    " VALUES(%Q,0,%d,:c)",
    zPathname, existsFlag
  );
  if( existsFlag ){
................................................................................
  db_step(&q);
  db_finalize(&q);
  if( existsFlag ){
    blob_reset(&content);
  }
  undoNeedRollback = 1;
}




















/*
** Complete the undo process is one is currently in process.
*/
void undo_finish(void){
  if( undoActive ){
    if( undoNeedRollback ){
................................................................................
/*
** COMMAND: undo
** COMMAND: redo
**
** Usage: %fossil undo ?--explain? ?FILENAME...?
**    or: %fossil redo ?--explain? ?FILENAME...?
**
** Undo the most recent update or merge or revert operation.  If FILENAME is







** specified then restore the content of the named file(s) but otherwise
** leave the update or merge or revert in effect.  The redo command undoes
** the effect of the most recent undo.
**
** If the --explain option is present, not changes are made and instead
** the undo or redo command explains what actions the undo or redo would
** have done had the --explain been omitted.
**
** A single level of undo/redo is supported.  The undo/redo stack
** is cleared by the commit and checkout commands.
*/
void undo_cmd(void){

/*
** Undo or redo all undoable or redoable changes.
*/
static void undo_all(int redoFlag){
  int ucid;
  int ncid;
  const char *zDb = db_name("localdb");
  undo_all_filesystem(redoFlag);
  db_multi_exec(
    "CREATE TEMP TABLE undo_vfile_2 AS SELECT * FROM vfile;"
    "DELETE FROM vfile;"
    "INSERT INTO vfile SELECT * FROM undo_vfile;"
    "DELETE FROM undo_vfile;"
    "INSERT INTO undo_vfile SELECT * FROM undo_vfile_2;"
................................................................................
    "CREATE TEMP TABLE undo_vmerge_2 AS SELECT * FROM vmerge;"
    "DELETE FROM vmerge;"
    "INSERT INTO vmerge SELECT * FROM undo_vmerge;"
    "DELETE FROM undo_vmerge;"
    "INSERT INTO undo_vmerge SELECT * FROM undo_vmerge_2;"
    "DROP TABLE undo_vmerge_2;"
  );
  if(db_exists("SELECT 1 FROM %s.sqlite_master WHERE name='undo_stash'", zDb) ){
    if( redoFlag ){
      db_multi_exec(
        "DELETE FROM stash WHERE stashid IN (SELECT stashid FROM undo_stash);"
        "DELETE FROM stashfile"
        " WHERE stashid NOT IN (SELECT stashid FROM stash);"
      );
    }else{
      db_multi_exec(
        "INSERT OR IGNORE INTO stash SELECT * FROM undo_stash;"
        "INSERT OR IGNORE INTO stashfile SELECT * FROM undo_stashfile;"
      );
    }
  }
  ncid = db_lget_int("undo_checkout", 0);
  ucid = db_lget_int("checkout", 0);
  db_lset_int("undo_checkout", ucid);
  db_lset_int("checkout", ncid);
}

/*
................................................................................
** Reset the undo memory.
*/
void undo_reset(void){
  static const char zSql[] =
    @ DROP TABLE IF EXISTS undo;
    @ DROP TABLE IF EXISTS undo_vfile;
    @ DROP TABLE IF EXISTS undo_vmerge;
    @ DROP TABLE IF EXISTS undo_stash;
    @ DROP TABLE IF EXISTS undo_stashfile;
    ;
  db_multi_exec(zSql);
  db_lset_int("undo_available", 0);
  db_lset_int("undo_checkout", 0);
}

/*
................................................................................
}

/*
** Begin capturing a snapshot that can be undone.
*/
void undo_begin(void){
  int cid;
  const char *zDb = db_name("localdb");
  static const char zSql[] = 
    @ CREATE TABLE %s.undo(
    @   pathname TEXT UNIQUE,             -- Name of the file
    @   redoflag BOOLEAN,                 -- 0 for undoable.  1 for redoable
    @   existsflag BOOLEAN,               -- True if the file exists
    @   content BLOB                      -- Saved content
    @ );
    @ CREATE TABLE %s.undo_vfile AS SELECT * FROM vfile;
    @ CREATE TABLE %s.undo_vmerge AS SELECT * FROM vmerge;
  ;
  if( undoDisable ) return;
  undo_reset();

  db_multi_exec(zSql, zDb, zDb, zDb);
  cid = db_lget_int("checkout", 0);
  db_lset_int("undo_checkout", cid);
  db_lset_int("undo_available", 1);
  db_lset("undo_cmdline", undoCmd);
  undoActive = 1;
}

................................................................................
void undo_save(const char *zPathname){
  char *zFullname;
  Blob content;
  int existsFlag;
  Stmt q;

  if( !undoActive ) return;
  zFullname = mprintf("%s%s", g.zLocalRoot, zPathname);
  existsFlag = file_size(zFullname)>=0;
  db_prepare(&q,
    "INSERT OR IGNORE INTO undo(pathname,redoflag,existsflag,content)"
    " VALUES(%Q,0,%d,:c)",
    zPathname, existsFlag
  );
  if( existsFlag ){
................................................................................
  db_step(&q);
  db_finalize(&q);
  if( existsFlag ){
    blob_reset(&content);
  }
  undoNeedRollback = 1;
}

/*
** Make the current state of stashid undoable.
*/
void undo_save_stash(int stashid){
  const char *zDb = db_name("localdb");
  db_multi_exec(
    "DROP TABLE IF EXISTS undo_stash;"
    "CREATE TABLE %s.undo_stash AS"
    " SELECT * FROM stash WHERE stashid=%d;",
    zDb, stashid
  );
  db_multi_exec(
    "DROP TABLE IF EXISTS undo_stashfile;"
    "CREATE TABLE %s.undo_stashfile AS"
    " SELECT * FROM stashfile WHERE stashid=%d;",
    zDb, stashid
  );
}

/*
** Complete the undo process is one is currently in process.
*/
void undo_finish(void){
  if( undoActive ){
    if( undoNeedRollback ){
................................................................................
/*
** COMMAND: undo
** COMMAND: redo
**
** Usage: %fossil undo ?--explain? ?FILENAME...?
**    or: %fossil redo ?--explain? ?FILENAME...?
**
** Undo the changes to the working checkout caused by the most recent
** of the following operations:
**
**    (1) fossil update             (5) fossil stash apply
**    (2) fossil merge              (6) fossil stash drop
**    (3) fossil revert             (7) fossil stash goto
**    (4) fossil stash pop
**
** If FILENAME is specified then restore the content of the named
** file(s) but otherwise leave the update or merge or revert in effect. 
** The redo command undoes the effect of the most recent undo.
**
** If the --explain option is present, no changes are made and instead
** the undo or redo command explains what actions the undo or redo would
** have done had the --explain been omitted.
**
** A single level of undo/redo is supported.  The undo/redo stack
** is cleared by the commit and checkout commands.
*/
void undo_cmd(void){

        errCode = 0;
      }
    }

    if( errCode==2 ){
      fossil_warning("file not in repository: %s", zFile);
    }else{
      char *zFull = mprintf("%//%/", g.zLocalRoot, zFile);
      undo_save(zFile);
      blob_write_to_file(&record, zFull);
      printf("REVERTED: %s\n", zFile);










      free(zFull);
    }
    blob_reset(&record);
  }
  db_finalize(&q);
  db_multi_exec("UPDATE vfile SET mtime=0 WHERE pathname IN torevert");
  undo_finish();
  db_end_transaction(0);
}

        errCode = 0;
      }
    }

    if( errCode==2 ){
      fossil_warning("file not in repository: %s", zFile);
    }else{
      char *zFull = mprintf("%/%/", g.zLocalRoot, zFile);
      undo_save(zFile);
      blob_write_to_file(&record, zFull);
      printf("REVERTED: %s\n", zFile);
      if( zRevision==0 ){
        sqlite3_int64 mtime = file_mtime(zFull);
        db_multi_exec(
           "UPDATE vfile"
           "   SET mtime=%lld, chnged=0, deleted=0,"
           "       pathname=coalesce(origname,pathname), origname=NULL"     
           " WHERE pathname=%Q",
           mtime, zFile
        );
      }
      free(zFull);
    }
    blob_reset(&record);
  }
  db_finalize(&q);

  undo_finish();
  db_end_transaction(0);
}