Drupal core 7.98 preg_match() function error on php 8.1

Hi @Cilefen,
I am getting this error from my drupal watchdog files.

Hi ,

I have applied below patch to fix this

index 5ed4a4ce..95951d5e 100644
--- a/docroot/includes/path.inc
+++ b/docroot/includes/path.inc
@@ -328,7 +328,7 @@ function drupal_match_path($path, $patterns) {
     $patterns_quoted = preg_quote($patterns, '/');
     $regexps[$patterns] = '/^(' . preg_replace($to_replace, $replacements, $patterns_quoted) . ')$/';
   }
-  return (bool)preg_match($regexps[$patterns], $path);
+  return (bool)preg_match($regexps[$patterns], (string) $path);
 }

 /**

The drupal_match_path() is called only 4x in Drupal 7 core (not counting the tests):

2x in path_is_admin() with argument current_path() (aka $_GET['q']), which cannot be empty/NULL.

2x in block_block_list_alter()
- the second one is using $_GET['q'] as well, which cannot be NULL.
- the first one is using drupal_get_path_alias($_GET['q']), but if this was the case, then you will end up with different error, as the result is used in drupal_strtolower() which also does not accept NULLs.

So I think this is caused by some contrib module/custom code . As @cilefen pointed out in #4, please provide more information (like backtrace, or steps to reproduce), so that we can do anything here. Thanks!