anchor.diff:      String text_delete = '';
       String text_insert = '';
       int commonlength;
  +    int start;
  +    int end;
       while (pointer < diffs.length) {
         switch (diffs[pointer].operation) {
           case DIFF_INSERT:
  
positive.code:             }
              patch.diffs.add(new Diff(diff_type, diff_text));
              if (diff_text == bigpatch.diffs[0].text) {
                bigpatch.diffs.removeRange(0, 1);
              } else {
                bigpatch.diffs[0].text = bigpatch.diffs[0].text
                    .substring(diff_text.length);
  
negative.code:         // Upon reaching an equality, check for prior redundancies.
          if (count_delete >= 1 && count_insert >= 1) {
            // Delete the offending records and add the merged ones.
            int start = pointer - count_delete - count_insert;
            int end = start + count_delete + count_insert;
            diffs.removeRange(start, end);
            pointer = pointer - count_delete - count_insert;
            final a = diff_main(text_delete.toString(), text_insert.toString(),
                false, deadline);
  