Prevent string index underrun

sebastianbergmann · Oct 30, 2024 · 8c4071f · 8c4071f
1 parent 860c0f2
commit 8c4071f
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/src/ScalarComparator.php b/src/ScalarComparator.php
@@ -140,7 +140,11 @@ private static function findCommonSuffix(string $string1, string $string2): stri
             return '';
         }
 
-        while ($string1[$lastCharIndex1] == $string2[$lastCharIndex2]) {
+        while (
+            $lastCharIndex1 > 0 &&
+            $lastCharIndex2 > 0 &&
+            $string1[$lastCharIndex1] == $string2[$lastCharIndex2]
+        ) {
             $lastCharIndex1--;
             $lastCharIndex2--;
         }