Merge pull request #554 from MoonchildProductions/issue12

Resolve potential null deref crashes in the editor

1 files changed, 12 insertions, 0 deletions

diff --git a/widget/BasicEvents.h b/widget/BasicEvents.h
index a6228f179..960cb67c6 100644
--- a/widget/BasicEvents.h
+++ b/widget/BasicEvents.h
@@ -161,6 +161,9 @@ public:
   }
   inline void PreventDefault(bool aCalledByDefaultHandler = true)
   {
+    if (!mCancelable) {
+      return;
+    }
     mDefaultPrevented = true;
     // Note that even if preventDefault() has already been called by chrome,
     // a call of preventDefault() by content needs to overwrite
@@ -175,6 +178,9 @@ public:
   // This should be used only before dispatching events into the DOM tree.
   inline void PreventDefaultBeforeDispatch()
   {
+    if (!mCancelable) {
+      return;
+    }
     mDefaultPrevented = true;
   }
   inline bool DefaultPrevented() const
@@ -407,10 +413,16 @@ public:
   nsString mSpecifiedEventTypeString;
 
   // Event targets, needed by DOM Events
+  // Note that when you need event target for DOM event, you should use
+  // Get*DOMEventTarget() instead of accessing these members directly.
   nsCOMPtr<dom::EventTarget> mTarget;
   nsCOMPtr<dom::EventTarget> mCurrentTarget;
   nsCOMPtr<dom::EventTarget> mOriginalTarget;
 
+  dom::EventTarget* GetDOMEventTarget() const;
+  dom::EventTarget* GetCurrentDOMEventTarget() const;
+  dom::EventTarget* GetOriginalDOMEventTarget() const;
+
   void AssignEventData(const WidgetEvent& aEvent, bool aCopyTargets)
   {
     // mClass should be initialized with the constructor.