Fossil

  char c = z[0];
  if( c=='/' || c==0 ) return 0;
  if( c=='.' ){
    if( z[1]=='/' || z[1]==0 ) return 0;
    if( z[1]=='.' && (z[2]=='/' || z[2]==0) ) return 0;
  }
  for(i=0; (c=z[i])!=0; i++){
    if( (c & 0xf0) == 0xf0 ) {
      /* Unicode characters > U+FFFF are not supported.
       * Windows XP and earlier cannot handle them.
       */
      return 0;
    }
    if( (c & 0xf0) == 0xe0 ) {
      /* This is a 3-byte UTF-8 character */
      if ( (c & 0xfe) == 0xee ){
        /* Range U+E000 - U+FFFF (Starting with 0xee or 0xef in UTF-8 ) */
        if ( (c & 1) && ((z[i+1] & 0xff) >= 0xa4) ){
          /* But exclude U+F900 - U+FFFF (0xef followed by byte >= 0xa4),
           * which contain valid characters. */
          continue;
        }
        /* Unicode character in the range U+E000 - U+F8FF are for
         * private use, they shouldn't occur in filenames.  */
        return 0;
      }
      if( ((c & 0xff) == 0xed) && ((z[i+1] & 0xe0) == 0xa0) ){
        /* Unicode character in the range U+D800 - U+DFFF are for
         * surrogate pairs, they shouldn't occur in filenames. */
        return 0;
      }
    }
    if( c=='\\' || c=='*' || c=='[' || c==']' || c=='?' ){
      return 0;
    }
    if( c=='/' ){
      if( z[i+1]=='/' ) return 0;
      if( z[i+1]=='.' ){
        if( z[i+2]=='/' || z[i+2]==0 ) return 0;