Merge pull request #2 from rmpel/masterHEAD1.1.0origin/masterorigin/HEADmaster

use a boundary that does not exist in the pattern.

1 files changed, 36 insertions, 6 deletions

diff --git a/lib/ereg.php b/lib/ereg.php
index 72a8943..e14b9b9 100644
--- a/lib/ereg.php
+++ b/lib/ereg.php
@@ -3,32 +3,62 @@ namespace {
     if (!function_exists('ereg')) {
         function ereg($pattern, $subject, &$matches = array())
         {
-            return preg_match('/'.$pattern.'/', $subject, $matches);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_match($boundary . $pattern . $boundary, $subject, $matches);
         }
 
         function eregi($pattern, $subject, &$matches = array())
         {
-            return preg_match('/'.$pattern.'/i', $subject, $matches);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_match($boundary . $pattern . $boundary . 'i', $subject, $matches);
         }
 
         function ereg_replace($pattern, $replacement, $string)
         {
-            return preg_replace('/'.$pattern.'/', $replacement, $string);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_replace($boundary . $pattern . $boundary, $replacement, $string);
         }
 
         function eregi_replace($pattern, $replacement, $string)
         {
-            return preg_replace('/'.$pattern.'/i', $replacement, $string);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_replace($boundary . $pattern . $boundary . 'i', $replacement, $string);
         }
 
         function split($pattern, $subject, $limit = -1)
         {
-            return preg_split('/'.$pattern.'/', $subject, $limit);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_split($boundary . $pattern . $boundary, $subject, $limit);
         }
 
         function spliti($pattern, $subject, $limit = -1)
         {
-            return preg_split('/'.$pattern.'/i', $subject, $limit);
+            $boundary = _ereg_determine_boundary($pattern);
+            return preg_split($boundary . $pattern . $boundary . 'i', $subject, $limit);
+        }
+
+        /**
+         * @method _ereg_determine_boundary Determine a valid boundary based on the pattern. 
+         * 
+         * @var string $pattern The possibly escaped pattern to match for. 
+         * @return string a suitable RegEx boundary
+         * 
+         * One would suggest just using preg_quote, but perhaps the pattern already is quoted, and therefore 
+         * using preg_quote would just double-quote and with that ruin the pattern.  
+         * The trick here is to find a boundary that is not within the pattern. 
+         * I have contemplated using "any ASCII charachter" but that would require detecting character classes
+         * and that's just too complicated.  
+         * The chance that all of these boundaries will conflict, and if so; new ones can be added :)
+         */
+        function _ereg_determine_boundary($pattern) 
+        {
+            foreach (array('/', '@', '#', '%', '±') as $boundary) {
+                if (false === strpos($pattern, $boundary)) { 
+                    return $boundary;
+                }
+            }
+
+            throw new Exception("Very sorry, could not shim the regular expression. Please follow the debug trace to see where the incompatible ereg-style function call is made.");
         }
     }
 }