342202 - canvas drawwindow() corruption if width >= 4091

Status: RESOLVED WONTFIX

(Core :: Graphics: Canvas2D, defect)

Description

[Kathleen :Brade]

I see corruption (garbage) in the image placed on the canvas when calling drawWindow() if the width is greater than 4090 pixels.  The height can vary between a few pixels and 32k without causing problems.  I see the corruption on Intel Mac as well as PowerPC Mac.  I don't see this problem on Windows or Linux.

The example I will attach is a little flakey but it reproduces the problem.  The example has a canvas element and an iframe.  The iframe's window is resized and drawn in the resized canvas after clicking the Resize button.  For some reason you will need to change the size and click the Resize button twice.

Comment 1

[Kathleen :Brade]

Attachment: png that shows corruption

Comment 2

[Kathleen :Brade]

Attachment: Example HTML

Steps to reproduce:
 * load this attachment in Firefox
 * click the Resize button
 * change the width value to 4092 (I like the pattern generated at this width)
 * click the Resize button

See the canvas rendered as garbage.
The canvas should render identically to the iframe below it (set the width value to 400 to see the expected behavior).

Comment 3

[Mark Smith [:mcs]]

I retested this today on Intel Mac OS 10.4.10.  I still see this bug in Firefox 2.0.0.8.  I do not see it in 3.0a8.

Does anyone know what change was made on the trunk to fix this?

Comment 4

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

Marking as wontfix; trunk uses a vastly different rendering architecture than the branch, so there's no chance of a backport to the branch.