Fossil

**   ExtFILE      Symbolic links always refer to the object to which the
**                link points.  Symlinks are never recognized as symlinks but
**                instead always appear to the the target object.
**
**   SymFILE      Symbolic links always appear to be files whose name is
**                the target pathname of the symbolic link.
**
**   RepoFILE     Like symfile is allow-symlinks is true, or like
**                ExtFile if allow-symlinks is false.  In other words,
**                symbolic links are only recognized as something different
**                from files or directories if allow-symlinks is true.
*/
#define ExtFILE    0  /* Always follow symlinks */
#define RepoFILE   1  /* Follow symlinks if and only if allow-symlinks is OFF */
#define SymFILE    2  /* Never follow symlinks */

  static const char *azReqTab[] = {
     "blob", "delta", "rcvfrom", "user", "config"
  };
  if( !file_isfile(zFilename, ExtFILE) ) return 0;
  sz = file_size(zFilename, ExtFILE);
  if( sz<35328 ) return 0;
  if( sz%512!=0 ) return 0;
  rc = sqlite3_open_v2(zFilename, &db, 
          SQLITE_OPEN_READWRITE, 0);
  if( rc!=0 ) goto not_a_repo;
  for(i=0; i<count(azReqTab); i++){
    if( sqlite3_table_column_metadata(db, "main", azReqTab[i],0,0,0,0,0,0) ){
      goto not_a_repo;
    }
  }

** zFilename is a symbolic link, it is the object that zFilename points
** to that is modified.
*/
int file_setexe(const char *zFilename, int onoff){
  int rc = 0;
#if !defined(_WIN32)
  struct stat buf;
  if( fossil_stat(zFilename, &buf, RepoFILE)!=0 
   || S_ISLNK(buf.st_mode)
   || S_ISDIR(buf.st_mode)
  ){
    return 0;
  }
  if( onoff ){
    int targetMode = (buf.st_mode & 0444)>>2;

      if( 8==nFilename ) return 1;
      return zEnd[-9]=='/' ? 2 : gotSuffix;
    }
    case 'T':
    case 't':{
      if( nFilename<9 || zEnd[-9]!='.'
       || fossil_strnicmp(".fslckout", &zEnd[-9], 9) ){
        return 0; 
      }
      if( 9==nFilename ) return 1;
      return zEnd[-10]=='/' ? 2 : gotSuffix;
    }
    default:{
      return 0;
    }
  }
}