diff --git a/mozilla/xpcom/ds/nsArrayEnumerator.cpp b/mozilla/xpcom/ds/nsArrayEnumerator.cpp
index 875a207908d..7cc14f90e89 100644
--- a/mozilla/xpcom/ds/nsArrayEnumerator.cpp
+++ b/mozilla/xpcom/ds/nsArrayEnumerator.cpp
@@ -132,8 +132,8 @@ NS_IMPL_ISUPPORTS1(nsCOMArrayEnumerator, nsISimpleEnumerator)
 nsCOMArrayEnumerator::~nsCOMArrayEnumerator()
 {
     // only release the entries that we haven't visited yet
-    while (mIndex < mArraySize) {
-        NS_IF_RELEASE(mValueArray[mIndex++]);
+    for (; mIndex < mArraySize; ++mIndex) {
+        NS_IF_RELEASE(mValueArray[mIndex]);
     }
 }