Bug #41707, #43652 --> JS urls aren't working. We need to check for the correct return value and don't propogate

the on start request in that case.
r=alecf

uriloader/base/nsURILoader.cpp

@@ -162,7 +162,9 @@ PRBool nsDocumentOpenInfo::ProcessCanceledCase(nsIChannel * aChannel)
   if (aChannel)
   {
     aChannel->GetStatus(&rv);
-    if (rv == NS_BINDING_ABORTED)
+
+    // if we were aborted or if the js returned no result (i.e. we aren't replacing any window content)
+    if (rv == NS_BINDING_ABORTED || rv == NS_ERROR_DOM_RETVAL_UNDEFINED)
     {
       canceled = PR_TRUE;
       // free any local state for this load since we are aborting it so we