Commit f20701416de for php.net

commit f20701416decead028551cb14cfc052a6b4750d0
Author: Niels Dossche <7771979+ndossche@users.noreply.github.com>
Date:   Fri Dec 26 03:15:25 2025 -0800

    mbstring: Transform RETURN_STR(zend_string_init_fast(...)) to RETURN_STRINGL_FAST(...) (#20779)

    This is a dedicated API which is cleaner.

diff --git a/ext/mbstring/mbstring.c b/ext/mbstring/mbstring.c
index 118986411a8..12c366c33d5 100644
--- a/ext/mbstring/mbstring.c
+++ b/ext/mbstring/mbstring.c
@@ -2448,7 +2448,7 @@ PHP_FUNCTION(mb_strcut)
 		if (len > string.len - from) {
 			len = string.len - from;
 		}
-		RETURN_STR(zend_string_init_fast((const char*)(string.val + from), len & -char_len));
+		RETURN_STRINGL_FAST((const char*)(string.val + from), len & -char_len);
 	}

 	if (enc->mblen_table) {
@@ -2471,7 +2471,7 @@ PHP_FUNCTION(mb_strcut)
 			}
 			end = p;
 		}
-		RETURN_STR(zend_string_init_fast((const char*)start, end - start));
+		RETURN_STRINGL_FAST((const char*)start, end - start);
 	}

 	ret = mbfl_strcut(&string, &result, from, len);