Bug 95929 – renderer()->view() is null

• Status: RESOLVED
• Resolution: INVALID
• Component: Layout and Rendering

[snyh]

in the begin of function "RenderLayer::convertToLayerCoord"

-----------------------------------------------------
   if (position == FixedPosition && !renderer()->inRenderFlowThread() && (!ancestorLayer || ancestorLayer == renderer()->view()->layer())) {
        // If the fixed layer's container is the root, just add in the offset of the view. We can obtain this by calling
        // localToAbsolute() on the RenderView.
        FloatPoint absPos = renderer()->localToAbsolute(FloatPoint(), true);
        location += LayoutSize(absPos.x(), absPos.y());
        return;
    }
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renderer()->view()  may be null when this layer hasn't destroy.

[Alexey Proskuryakov]

Do you happen to have a test case where this happens in practice?

[snyh]

(In reply to comment #1)
> Do you happen to have a test case where this happens in practice?

Sorry, I can't get an simply test case.
I have modify the RenderLayer, FrameView etc.


If you need an test case with modify some lite WebCore's code, I can provide one at the later.  


But the point is 
  use renderLayer->absoluteBoundingBox() when the time page reload with two or more div has style "z-index: 0+; position:fixed".  the webcore will crash.

I can sure the RenderLayer and its m_renderer hasn't destroy when doing this.
The problem is at this time the m_renderer has detached from RenderView? 


Now I have test if frame()->document()->renderView() valid when doing other things in my code.

[snyh]

Or in RenderLayer::convertToLayerCoord simply test renderer()->view() is valid.

But I see many place invoke renderer()->view()->otherthing without test.
So Is this is my fault?

[Julien Chaffraix]

(In reply to comment #3)
> Or in RenderLayer::convertToLayerCoord simply test renderer()->view() is valid.
> 
> But I see many place invoke renderer()->view()->otherthing without test.
> So Is this is my fault?

Very likely. renderer()->view() is NULL during Document's tear down FWIW. If you have modified WebKit (especially some core rendering objects like RenderLayer), you are on your own.

Unless this reproduces against an unmodified WebKit codebase and you provide a way for us to reproduce that, we will consider this to be a bug in your code, not WebKit.