Fossil

#define DIFF_NUMSTAT      ((u64)0x80000000) /* Show line count of changes */
#define DIFF_NOOPT        (((u64)0x01)<<32) /* Suppress optimizations (debug) */
#define DIFF_INVERT       (((u64)0x02)<<32) /* Invert the diff (debug) */
#define DIFF_CONTEXT_EX   (((u64)0x04)<<32) /* Use context even if zero */
#define DIFF_NOTTOOBIG    (((u64)0x08)<<32) /* Only display if not too big */
#define DIFF_STRIP_EOLCR  (((u64)0x10)<<32) /* Strip trailing CR */
#define DIFF_SLOW_SBS     (((u64)0x20)<<32) /* Better but slower side-by-side */
#define DIFF_IGNORE_PADDS (((u64)0x40)<<32) /* Ignore sections of purely adds */

/*
** These error messages are shared in multiple locations.  They are defined
** here for consistency.
*/
#define DIFF_CANNOT_COMPUTE_BINARY \
    "cannot compute difference between binary files\n"

  int i, j;     /* Loop counters */
  int m;        /* Number of lines to output */
  int skip;     /* Number of lines to skip */
  static int nChunk = 0;  /* Number of diff chunks seen so far */
  int nContext;    /* Number of lines of context */
  int showLn;      /* Show line numbers */
  int html;        /* Render as HTML */
  int noPureAdds;  /* Ignore sections that are purely additions */
  int showDivider = 0;  /* True to show the divider between diff blocks */

  nContext = diff_context_lines(diffFlags);
  showLn = (diffFlags & DIFF_LINENO)!=0;
  html = (diffFlags & DIFF_HTML)!=0;
  noPureAdds = (diffFlags & DIFF_IGNORE_PADDS)!=0;
  A = p->aFrom;
  B = p->aTo;
  R = p->aEdit;
  mxr = p->nEdit;
  while( mxr>2 && R[mxr-1]==0 && R[mxr-2]==0 ){ mxr -= 3; }
  for(r=0; r<mxr; r += 3*nr){
    /* Figure out how many triples to show in a single block */

      appendDiffLine(pOut, ' ', &A[a+j], html, 0);
    }
    a += m;
    b += m;

    /* Show the differences */
    for(i=0; i<nr; i++){
      int nDels = 0;
      m = R[r+i*3+1];
      for(j=0; j<m; j++){
        if( showLn ) appendDiffLineno(pOut, a+j+1, 0, html);
        appendDiffLine(pOut, '-', &A[a+j], html, pRe);
        nDels++;
      }
      a += m;
      m = R[r+i*3+2];
      for(j=0; j<m; j++){
        char cPrefix = '+';
        if( noPureAdds && nDels==0 ) cPrefix = ' ';
        if( showLn ) appendDiffLineno(pOut, 0, b+j+1, html);
        appendDiffLine(pOut, cPrefix, &B[b+j], html, pRe);
      }
      b += m;
      if( i<nr-1 ){
        m = R[r+i*3+3];
        for(j=0; j<m; j++){
          if( showLn ) appendDiffLineno(pOut, a+j+1, b+j+1, html);
          appendDiffLine(pOut, ' ', &A[a+j], html, 0);

**   --checkin VERSION          Show diff of all changes in VERSION
**   --command PROG             External diff program - overrides "diff-command"
**   --context|-c N             Use N lines of context
**   --diff-binary BOOL         Include binary files when using external commands
**   --exec-abs-paths           Force absolute path names with external commands.
**   --exec-rel-paths           Force relative path names with external commands.
**   --from|-r VERSION          Select VERSION as source for the diff
**   --ignore-pure-adds         Ignore all sections containing only additions.
**   --internal|-i              Use internal diff logic
**   --new-file|-N              Show complete text of added and deleted files
**   --numstat                  Show only the number of lines delete and added
**   --side-by-side|-y          Side-by-side diff
**   --strip-trailing-cr        Strip trailing CR
**   --tk                       Launch a Tcl/Tk GUI for display
**   --to VERSION               Select VERSION as target for the diff

  againstUndo = find_option("undo",0,0)!=0;
  diffFlags = diff_options();
  verboseFlag = find_option("verbose","v",0)!=0;
  if( !verboseFlag ){
    verboseFlag = find_option("new-file","N",0)!=0; /* deprecated */
  }
  if( verboseFlag ) diffFlags |= DIFF_VERBOSE;
  if( find_option("ignore-pure-adds",0,0)!=0 ) diffFlags |= DIFF_IGNORE_PADDS;
  if( againstUndo && ( zFrom!=0 || zTo!=0 || zCheckin!=0 || zBranch!=0) ){
    fossil_fatal("cannot use --undo together with --from, --to, --checkin,"
                 " or --branch");
  }
  if( zBranch ){
    if( zTo || zFrom || zCheckin ){
      fossil_fatal("cannot use --from, --to, or --checkin with --branch");

**   to=TAG          Right side of the comparison
**   branch=TAG      Show all changes on a particular branch
**   diff=INTEGER    0: none, 1: unified, 2: side-by-side
**   glob=STRING     only diff files matching this glob
**   dc=N            show N lines of context around each diff
**   w=BOOLEAN       ignore whitespace when computing diffs
**   nohdr           omit the description at the top of the page
**   nopureadds      Ignore all sections containing only additions
**
**
** Show all differences between two check-ins.
*/
void vdiff_page(void){
  int ridFrom, ridTo;
  int diffType = 0;        /* 0: none, 1: unified, 2: side-by-side */

  zGlob = P("glob");
  zFrom = P("from");
  zTo = P("to");
  if(zGlob && !*zGlob){
    zGlob = NULL;
  }
  diffFlags = construct_diff_flags(diffType);
  if( P("nopureadds") ) diffFlags |= DIFF_IGNORE_PADDS;
  zW = (diffFlags&DIFF_IGNORE_ALLWS)?"&w":"";
  style_submenu_element("Path", "%R/timeline?me=%T&you=%T", zFrom, zTo);
  if( diffType!=0 ){
    style_submenu_element("Hide Diff", "%R/vdiff?from=%T&to=%T&diff=0%s%T%s",
                          zFrom, zTo,
                          zGlob ? "&glob=" : "", zGlob ? zGlob : "", zW);
  }