Bug 333505: nsLocalFileOSX crash. Original patch by Shane Caraveo <shanec@ActiveState.com>, review nits addressed by me. Unit test by Callek. r=mentovai, r/sr=bsmedberg, a1.9=damons

xpcom/io/nsLocalFileOSX.mm

@@ -183,6 +183,11 @@ class nsDirEnumerator : public nsISimpleEnumerator,
         {
           NS_OBJC_BEGIN_TRY_ABORT_BLOCK_NSRESULT;
 
+          if (!mIterator || !mFSRefsArray) {
+            *result = PR_FALSE;
+            return NS_OK;
+          }
+
           if (mNext == nsnull) {
             if (mArrayIndex >= mArrayCnt) {
               ItemCount actualCnt;
@@ -201,6 +206,7 @@ class nsDirEnumerator : public nsISimpleEnumerator,
                 mArrayIndex = 0;
               }
             }
+
             if (mArrayIndex < mArrayCnt) {
               nsLocalFile *newFile = new nsLocalFile;
               if (!newFile)
@@ -212,9 +218,11 @@ class nsDirEnumerator : public nsISimpleEnumerator,
               mNext = newFile;
             } 
           }
+
           *result = mNext != nsnull;
           if (!*result)
             Close();
+
           return NS_OK;
 
           NS_OBJC_END_TRY_ABORT_BLOCK_NSRESULT;

xpcom/tests/unit/test_bug333505.js

@@ -0,0 +1,10 @@
+function run_test()
+{
+  var dirEntries = do_get_file("xpcom/tests/unit/").directoryEntries;
+
+  while (dirEntries.hasMoreElements())
+    dirEntries.getNext();
+
+  // We ensure there is no crash
+  dirEntries.hasMoreElements();
+}