Make sure to propagate back the result of InstallImplementation and bail

if it fails.  Bug 292944, r+sr=jst, a=asa

content/xbl/src/nsXBLBinding.cpp

@@ -721,18 +721,22 @@ nsXBLBinding::InstallEventHandlers()
     mNextBinding->InstallEventHandlers();
 }
 
-void
+nsresult
 nsXBLBinding::InstallImplementation()
 {
   // Always install the base class properties first, so that
   // derived classes can reference the base class properties.
 
-  if (mNextBinding)
-    mNextBinding->InstallImplementation();
-
+  if (mNextBinding) {
+    nsresult rv = mNextBinding->InstallImplementation();
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+  
   // iterate through each property in the prototype's list and install the property.
   if (AllowScripts())
-    mPrototypeBinding->InstallImplementation(mBoundElement);
+    return mPrototypeBinding->InstallImplementation(mBoundElement);
+
+  return NS_OK;
 }
 
 nsIAtom*

content/xbl/src/nsXBLBinding.h

@@ -111,7 +111,7 @@ public:
   void GenerateAnonymousContent();
   void InstallAnonymousContent(nsIContent* aAnonParent, nsIContent* aElement);
   void InstallEventHandlers();
-  void InstallImplementation();
+  nsresult InstallImplementation();
 
   void ExecuteAttachedHandler();
   void ExecuteDetachedHandler();

content/xbl/src/nsXBLService.cpp

@@ -639,7 +639,8 @@ nsXBLService::LoadBindings(nsIContent* aContent, nsIURI* aURL, PRBool aAugmentFl
   newBinding->InstallEventHandlers();
 
   // Set up our properties
-  newBinding->InstallImplementation();
+  rv = newBinding->InstallImplementation();
+  NS_ENSURE_SUCCESS(rv, rv);
 
   // Figure out if we need to execute a constructor.
   *aBinding = newBinding->GetFirstBindingWithConstructor();