From 9135f0991b9b83fbd7980968348c7f17ff2930b3 Mon Sep 17 00:00:00 2001
From: "Yukihiro \"Matz\" Matsumoto" <matz@ruby.or.jp>
Date: Tue, 9 Jan 2024 11:44:12 +0900
Subject: [PATCH] string.c: avoid RSTRING_CHAR_LEN() if possible

Current code scan the string twice (once from RSTRING_CHAR_LEN, and once
from chars2bytes), but those scans are not necessary. Just point the end
of the string.
---
 src/string.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/string.c b/src/string.c
index f4011756f..562a62bd7 100644
--- a/src/string.c
+++ b/src/string.c
@@ -2070,8 +2070,7 @@ mrb_str_rindex_m(mrb_state *mrb, mrb_value str)
   mrb_int pos;
 
   if (mrb_get_args(mrb, "S|i", &sub, &pos) == 1) {
-    pos = RSTRING_CHAR_LEN(str);
-    pos = chars2bytes(str, 0, pos);
+    pos = RSTRING_LEN(str);
   }
   else if (pos >= 0) {
     pos = chars2bytes(str, 0, pos);