Improved error-handling of \wcf\system\Regex

diff --git a/wcfsetup/install/files/lib/system/Regex.class.php b/wcfsetup/install/files/lib/system/Regex.class.php
index 5f9ade7c63cc3fb8bced20b6e8e274b67cf5c58e..966f698a2bfd54ac7915f99abf78809e0027718a 100644 (file)
--- a/wcfsetup/install/files/lib/system/Regex.class.php
+++ b/wcfsetup/install/files/lib/system/Regex.class.php
@@ -112,16 +112,10 @@ final class Regex {
         */
        public function match($string, $all = false) {
                if ($all) {
-                       $result = preg_match_all($this->regex, $string, $this->matches);
-               }
-               else {
-                       $result = preg_match($this->regex, $string, $this->matches);
+                       return $this->checkResult(preg_match_all($this->regex, $string, $this->matches), 'match');
                }
                
-               if ($result === false) {
-                       throw new SystemException('Could not execute match on '.$this->regex);
-               }
-               return $result;
+               return $this->checkResult(preg_match($this->regex, $string, $this->matches), 'match');
        }
        
        /**
@@ -133,16 +127,10 @@ final class Regex {
         */
        public function replace($string, $replacement) {
                if ($replacement instanceof Callback) {
-                       $result = preg_replace_callback($this->regex, $replacement, $string);
-               }
-               else {
-                       $result = preg_replace($this->regex, $replacement, $string);
+                       return $this->checkResult(preg_replace_callback($this->regex, $replacement, $string), 'replace');
                }
                
-               if ($result === false) {
-                       throw new SystemException('Could not execute replace on '.$this->regex);
-               }
-               return $result;
+               return $this->checkResult(preg_replace($this->regex, $replacement, $string), 'replace');
        }
        
        /**
@@ -152,10 +140,34 @@ final class Regex {
         * @return      array<string>
         */
        public function split($string) {
-               $result = preg_split($this->regex, $string);
-               
+               return $this->checkResult(preg_split($this->regex, $string), 'split');
+       }
+       
+       /**
+        * Checks whether there was success.
+        *
+        * @param       mixed   $result
+        */
+       private function checkResult($result, $method = '') {
                if ($result === false) {
-                       throw new SystemException('Could not execute split on '.$this->regex);
+                       switch (preg_last_error()) {
+                               case PREG_INTERNAL_ERROR:
+                                       $error = 'Internal error';
+                               break;
+                               case PREG_BACKTRACK_LIMIT_ERROR:
+                                       $error = 'Backtrack limit was exhausted';
+                               break;
+                               case PREG_RECURSION_LIMIT_ERROR:
+                                       $error = 'Recursion limit was exhausted';
+                               break;
+                               case PREG_BAD_UTF8_ERROR:
+                                       $error = 'Bad UTF8';
+                               break;
+                               default:
+                                       $error = 'Unknown error';
+                       }
+
+                       throw new SystemException('Could not execute '.($method ? $method.' on ' : '').$this->regex.': '.$error);
                }
                return $result;
        }