vim-patch:9.1.1445: negative matchfuzzy scores although there is a match (#34409)

Problem:  negative matchfuzzy scores although there is a match
          (Maxim Kim)
Solution: reset the score if a match has been found but the score is
          negative (Girish Palya)

The fuzzy algorithm may miss some matches in long strings due to recursion
limits. As a result, the score can end up negative even when matches exist.
In such cases, reset the score to ensure it is non-negative.

fixes: #vim/vim#17449
closes: vim/vim#17469

328332b0b0

Co-authored-by: Girish Palya <girishji@gmail.com>

src/nvim/search.c

@@ -3021,6 +3021,11 @@ static int fuzzy_match_compute_score(const char *const fuzpat, const char *const
   // Apply unmatched penalty
   const int unmatched = strSz - numMatches;
   score += UNMATCHED_LETTER_PENALTY * unmatched;
+  // In a long string, not all matches may be found due to the recursion limit.
+  // If at least one match is found, reset the score to a non-negative value.
+  if (score < 0 && numMatches > 0) {
+    score = 0;
+  }
 
   // Apply ordering bonuses
   for (int i = 0; i < numMatches; i++) {