}else{
    vprintf(zFormat, ap);
  }
  va_end(ap);
}

/*
** Print the "Index:" message that patch wants to see at the top of a diff.
** Print the "Index:" message that patches wants to see at the top of a diff.
*/
void diff_print_index(const char *zFile){
  diff_printf("Index: %s\n======================================="
              "============================\n", zFile);
void diff_print_index(const char *zFile, int diffFlags){
  if( (diffFlags & DIFF_SIDEBYSIDE)==0 ){
    char *z = mprintf("Index: %s\n%.66c\n", zFile, '=');
    diff_printf("%s", z);
    fossil_free(z);
  }
}

/*
** Print the +++/--- filename lines for a diff operation.
*/
void diff_print_filenames(const char *zLeft, const char *zRight, int diffFlags){
  char *z = 0;
  if( diffFlags & DIFF_SIDEBYSIDE ){
    int w = diff_width(diffFlags);
    int n1 = strlen(zLeft);
    int x;
    if( n1>w*2 ) n1 = w*2;
    x = w*2+17 - (n1+2);
    z = mprintf("%.*c %.*s %.*c\n",
                x/2, '=', n1, zLeft, (x+1)/2, '=');
  }else{
    z = mprintf("--- %s\n+++ %s\n", zLeft, zRight);
  }
  diff_printf("%s", z);
  fossil_free(z);
}

/*
** Show the difference between two files, one in memory and one on disk.
**
** The difference is the set of edits needed to transform pFile1 into
** zFile2.  The content of pFile1 is in memory.  zFile2 exists on disk.

      zName2 = zName;
    }

    /* Compute and output the differences */
    blob_zero(&out);
    text_diff(pFile1, &file2, &out, diffFlags);
    if( blob_size(&out) ){
      diff_printf("--- %s\n+++ %s\n", zName, zName2);
      diff_print_filenames(zName, zName2, diffFlags);
      diff_printf("%s\n", blob_str(&out));
    }

    /* Release memory resources */
    blob_reset(&file2);
    blob_reset(&out);
  }else{

  int diffFlags             /* Diff flags */
){
  if( zDiffCmd==0 ){
    Blob out;      /* Diff output text */

    blob_zero(&out);
    text_diff(pFile1, pFile2, &out, diffFlags);
    diff_printf("--- %s\n+++ %s\n", zName, zName);
    diff_print_filenames(zName, zName, diffFlags);
    diff_printf("%s\n", blob_str(&out));

    /* Release memory resources */
    blob_reset(&out);
  }else{
    Blob cmd;
    char zTemp1[300];

      diff_printf("ADDED_BY_MERGE %s\n", zPathname);
      srcid = 0;
      if( !asNewFile ){ showDiff = 0; }
    }
    if( showDiff ){
      Blob content;
      if( !isLink != !file_wd_islink(zFullName) ){
        diff_print_index(zPathname);
        diff_printf("--- %s\n+++ %s\n", zPathname, zPathname);
        diff_print_index(zPathname, diffFlags);
        diff_print_filenames(zPathname, zPathname, diffFlags);
        diff_printf("cannot compute difference between symlink and regular file\n");
        continue;
      }
      if( srcid>0 ){
        content_get(srcid, &content);
      }else{
        blob_zero(&content);
      }
      diff_print_index(zPathname);
      diff_print_index(zPathname, diffFlags);
      diff_file(&content, zFullName, zPathname, zDiffCmd, diffFlags);
      blob_reset(&content);
    }
    free(zToFree);
  }
  db_finalize(&q);
  db_end_transaction(1);  /* ROLLBACK */

  Blob v1, v2;
  int isLink1, isLink2;
  file_tree_name(zFileTreeName, &fname, 1);
  zName = blob_str(&fname);
  historical_version_of_file(zFrom, zName, &v1, &isLink1, 0, 0);
  historical_version_of_file(zTo, zName, &v2, &isLink2, 0, 0);
  if( isLink1 != isLink2 ){
    diff_printf("--- %s\n+++ %s\n", zName, zName);
    diff_print_filenames(zName, zName, diffFlags);
    diff_printf("cannot compute difference between symlink and regular file\n");
  }else{
    diff_file_mem(&v1, &v2, zName, zDiffCmd, diffFlags);
  }
  blob_reset(&v1);
  blob_reset(&v2);
  blob_reset(&fname);

  struct ManifestFile *pTo,
  const char *zDiffCmd,
  int diffFlags
){
  Blob f1, f2;
  int rid;
  const char *zName =  pFrom ? pFrom->zName : pTo->zName;
  diff_print_index(zName);
  diff_print_index(zName, diffFlags);
  if( pFrom ){
    rid = uuid_to_rid(pFrom->zUuid, 0);
    content_get(rid, &f1);
  }else{
    blob_zero(&f1);
  }
  if( pTo ){

  int isGDiff;               /* True for gdiff.  False for normal diff */
  int isInternDiff;          /* True for internal diff */
  int hasNFlag;              /* True if -N or --new-file flag is used */
  const char *zFrom;         /* Source version number */
  const char *zTo;           /* Target version number */
  const char *zDiffCmd = 0;  /* External diff command. NULL for internal diff */
  int diffFlags = 0;         /* Flags to control the DIFF */
  const char *z;
  int f;

  isGDiff = g.argv[1][0]=='g';
  isInternDiff = find_option("internal","i",0)!=0;
  zFrom = find_option("from", "r", 1);
  zTo = find_option("to", 0, 1);
  diffFlags = diff_options();
  hasNFlag = find_option("new-file","N",0)!=0;
  if( find_option("side-by-side","y",0)!=0 ) diffFlags |= DIFF_SIDEBYSIDE;
  if( (z = find_option("context","c",1))!=0 && (f = atoi(z))>0 ){
    if( f > DIFF_CONTEXT_MASK ) f = DIFF_CONTEXT_MASK;
    diffFlags |= f;
  }
  if( hasNFlag ) diffFlags |= DIFF_NEWFILE;

  if( (z = find_option("width","W",1))!=0 && (f = atoi(z))>0 ){
    f *= DIFF_CONTEXT_MASK+1;
    if( f > DIFF_WIDTH_MASK ) f = DIFF_CONTEXT_MASK;
    diffFlags |= f;
  }


  if( hasNFlag ) diffFlags |= DIFF_NEWFILE;
  if( zTo==0 ){
    db_must_be_within_tree();
    verify_all_options();
    if( !isInternDiff ){
      zDiffCmd = db_get(isGDiff ? "gdiff-command" : "diff-command", 0);
    }
    if( g.argc>=3 ){
      for(f=2; f<g.argc; ++f){
        diff_one_against_disk(zFrom, zDiffCmd, 0, g.argv[f]);
        diff_one_against_disk(zFrom, zDiffCmd, diffFlags, g.argv[f]);
      }
    }else{
      diff_all_against_disk(zFrom, zDiffCmd, diffFlags);
    }
  }else if( zFrom==0 ){
    fossil_fatal("must use --from if --to is present");
  }else{
    db_find_and_open_repository(0, 0);
    verify_all_options();
    if( !isInternDiff ){
      zDiffCmd = db_get(isGDiff ? "gdiff-command" : "diff-command", 0);
    }
    if( g.argc>=3 ){
      for(f=2; f<g.argc; ++f){
        diff_one_two_versions(zFrom, zTo, zDiffCmd, 0, g.argv[f]);        
        diff_one_two_versions(zFrom, zTo, zDiffCmd, diffFlags, g.argv[f]);        
      }
    }else{
      diff_all_two_versions(zFrom, zTo, zDiffCmd, diffFlags);
    }
  }
}