Fix review

Author: Fan2Shrek

src/Mbstring/Mbstring.php

@@ -1034,7 +1034,7 @@ private static function mb_internal_trim(string $regex, string $string, ?string
 
             return $test;
         } catch (\Exception $e) {
-            return preg_replace($regex, "", $string);
+            return preg_replace('/'.$regex.'/', "", $string);
         }
     } 
 

src/Php84/bootstrap.php

@@ -39,14 +39,14 @@ function array_any(array $array, callable $callback): bool { return p\Php84::arr
     function array_all(array $array, callable $callback): bool { return p\Php84::array_all($array, $callback); }
 }
 
-if (!function_exists('mb_trim')) {
+if (!function_exists('mb_trim') && extension_loaded('mbstring')) {
     function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_trim($string, $characters, $encoding); }
 }
 
-if (!function_exists('mb_ltrim')) {
+if (!function_exists('mb_ltrim') && extension_loaded('mbstring')) {
     function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_ltrim($string, $characters, $encoding); }
 }
 
-if (!function_exists('mb_rtrim')) {
+if (!function_exists('mb_rtrim') && extension_loaded('mbstring')) {
     function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_rtrim($string, $characters, $encoding); }
 }