1diff --git a/src/common/str_util.c b/src/common/str_util.c 2index cc825cb..5a0b8b1 100644 3--- a/src/common/str_util.c 4+++ b/src/common/str_util.c 5@@ -507,7 +507,7 @@ size_t mg_match_prefix_n(const struct mg_str pattern, const struct mg_str str) { 6 const struct mg_str pstr = {pattern.p + i, pattern.len - i}; 7 const struct mg_str sstr = {str.p + j + len, str.len - j - len}; 8 res = mg_match_prefix_n(pstr, sstr); 9- } while (res == 0 && len != 0 && len-- > 0); 10+ } while (res == 0 && len != 0 && --len > 0); 11 return res == 0 ? 0 : j + res + len; 12 } else if (str_util_lowercase(&pattern.p[i]) != 13 str_util_lowercase(&str.p[j])) { 14