MD5Init(&ctx);
  MD5Update(&ctx,zTxt,nLen);
  MD5Final(digest,&ctx);
  for(j=i=0; i<16; i++,j+=2){
    bprintf(&zETag[j],sizeof(zETag)-j,"%02x",(int)digest[i]);
  }
  blob_appendf(&extraHeader, "ETag: %s\r\n", zETag);
  return fossil_strdup(zETag);
}

/*
** Do some cache control stuff. First, we generate an ETag and include it in
** the response headers. Second, we do whatever is necessary to determine if
** the request was asking about caching and whether we need to send back the
** response body. If we shouldn't send a body, return non-zero.
**
** Currently, we just check the ETag against any If-None-Match header.
**
** FIXME: In some cases (attachments, file contents) we could check
** If-Modified-Since headers and always include Last-Modified in responses.
*/
static int check_cache_control(void){
  /* FIXME: there's some gotchas wth cookies and some headers. */
  char *zETag = cgi_add_etag(blob_buffer(&cgiContent),blob_size(&cgiContent));
  char *zMatch = P("HTTP_IF_NONE_MATCH");

  if( zETag!=0 && zMatch!=0 ) {
    char *zBuf = fossil_strdup(zMatch);
    if( zBuf!=0 ){
      char *zTok = 0;
      char *zPos;
      for( zTok = strtok_r(zBuf, ",\"",&zPos);
           zTok && fossil_stricmp(zTok,zETag);
           zTok =  strtok_r(0, ",\"",&zPos)){}
      fossil_free(zBuf);
      if(zTok) return 1;
    }
  }
  
  return 0;
}
#endif

  ImportFile *aFile;          /* Information about files in a commit */
  int fromLoaded;             /* True zFrom content loaded into aFile[] */
} gg;

/*
** Duplicate a string.
*/
char *fossil_strdup(const char *zOrig){
  char *z = 0;
  if( zOrig ){
    int n = strlen(zOrig);
    z = fossil_malloc( n+1 );
    memcpy(z, zOrig, n+1);
  }
  return z;

        "INSERT INTO xtag(tname, trid, tuuid)"
        "VALUES(%B,%d,%B)", 
        &hash, rid, &hash
    );
  }
  if( saveUuid ){
    fossil_free(gg.zPrevCheckin);
    gg.zPrevCheckin = fossil_strdup(blob_str(&hash));
  }
  blob_reset(&hash);
  return rid;
}

/*
** Use data accumulated in gg from a "blob" record to add a new file

  rid = fast_uuid_to_rid(gg.zFrom);
  if( rid==0 ) return;
  p = manifest_get(rid, CFTYPE_MANIFEST);
  if( p==0 ) return;
  manifest_file_rewind(p);
  while( (pOld = manifest_file_next(p, 0))!=0 ){
    pNew = import_add_file();
    pNew->zName = fossil_strdup(pOld->zName);
    pNew->isExe = pOld->zPerm && strstr(pOld->zPerm, "x")!=0;
    pNew->zUuid = fossil_strdup(pOld->zUuid);
    pNew->isFrom = 1;
  }
  manifest_destroy(p);
}

/*
** Locate a file in the gg.aFile[] array by its name.  Begin the search

    if( memcmp(zLine, "commit ", 7)==0 ){
      gg.xFinish();
      gg.xFinish = finish_commit;
      trim_newline(&zLine[7]);
      z = &zLine[7];
      for(i=strlen(z)-1; i>=0 && z[i]!='/'; i--){}
      if( z[i+1]!=0 ) z += i+1;
      gg.zBranch = fossil_strdup(z);
      gg.fromLoaded = 0;
    }else
    if( memcmp(zLine, "tag ", 4)==0 ){
      gg.xFinish();
      gg.xFinish = finish_tag;
      trim_newline(&zLine[4]);
      gg.zTag = fossil_strdup(&zLine[4]);
    }else
    if( memcmp(zLine, "reset ", 4)==0 ){
      gg.xFinish();
    }else
    if( memcmp(zLine, "checkpoint", 10)==0 ){
      gg.xFinish();
    }else

    }else
    if( memcmp(zLine, "author ", 7)==0 ){
      /* No-op */
    }else
    if( memcmp(zLine, "mark ", 5)==0 ){
      trim_newline(&zLine[5]);
      fossil_free(gg.zMark);
      gg.zMark = fossil_strdup(&zLine[5]);
    }else
    if( memcmp(zLine, "tagger ", 7)==0 || memcmp(zLine, "committer ",10)==0 ){
      sqlite3_int64 secSince1970;
      for(i=0; zLine[i] && zLine[i]!='<'; i++){}
      if( zLine[i]==0 ) goto malformed_line;
      z = &zLine[i+1];
      for(i=i+1; zLine[i] && zLine[i]!='>'; i++){}
      if( zLine[i]==0 ) goto malformed_line;
      zLine[i] = 0;
      fossil_free(gg.zUser);
      gg.zUser = fossil_strdup(z);
      secSince1970 = 0;
      for(i=i+2; fossil_isdigit(zLine[i]); i++){
        secSince1970 = secSince1970*10 + zLine[i] - '0';
      }
      fossil_free(gg.zDate);
      gg.zDate = db_text(0, "SELECT datetime(%lld, 'unixepoch')", secSince1970);
      gg.zDate[10] = 'T';
    }else
    if( memcmp(zLine, "from ", 5)==0 ){
      trim_newline(&zLine[5]);
      fossil_free(gg.zFromMark);
      gg.zFromMark = fossil_strdup(&zLine[5]);
      fossil_free(gg.zFrom);
      gg.zFrom = resolve_committish(&zLine[5]);
    }else
    if( memcmp(zLine, "merge ", 6)==0 ){
      trim_newline(&zLine[6]);
      if( gg.nMerge>=gg.nMergeAlloc ){
        gg.nMergeAlloc = gg.nMergeAlloc*2 + 10;

      zPerm = next_token(&z);
      zUuid = next_token(&z);
      zName = rest_of_line(&z);
      i = 0;
      pFile = import_find_file(zName, &i, gg.nFile);
      if( pFile==0 ){
        pFile = import_add_file();
        pFile->zName = fossil_strdup(zName);
      }
      pFile->isExe = (fossil_strcmp(zPerm, "100755")==0);
      fossil_free(pFile->zUuid);
      pFile->zUuid = resolve_committish(zUuid);
      pFile->isFrom = 0;
    }else
    if( memcmp(zLine, "D ", 2)==0 ){

      while( (pFile = import_find_file(zFrom, &i, mx))!=0 ){
        if( pFile->isFrom==0 ) continue;
        pNew = import_add_file();
        pFile = &gg.aFile[i-1];
        if( strlen(pFile->zName)>nFrom ){
          pNew->zName = mprintf("%s%s", zTo, pFile->zName[nFrom]);
        }else{
          pNew->zName = fossil_strdup(pFile->zName);
        }
        pNew->isExe = pFile->isExe;
        pNew->zUuid = fossil_strdup(pFile->zUuid);
        pNew->isFrom = 0;
      }
    }else
    if( memcmp(zLine, "R ", 2)==0 ){
      int nFrom;
      import_prior_files();
      z = &zLine[2];
      zFrom = next_token(&z);
      zTo = rest_of_line(&z);
      i = 0;
      nFrom = strlen(zFrom);
      while( (pFile = import_find_file(zFrom, &i, gg.nFile))!=0 ){
        if( pFile->isFrom==0 ) continue;
        pNew = import_add_file();
        pFile = &gg.aFile[i-1];
        if( strlen(pFile->zName)>nFrom ){
          pNew->zName = mprintf("%s%s", zTo, pFile->zName[nFrom]);
        }else{
          pNew->zName = fossil_strdup(pFile->zName);
        }
        pNew->zPrior = pFile->zName;
        pNew->isExe = pFile->isExe;
        pNew->zUuid = pFile->zUuid;
        pNew->isFrom = 0;
        gg.nFile--;
        *pFile = *pNew;