449653 - drawWindow on canvas fails on load, draws white instead of specified region

Status: RESOLVED FIXED

(Core :: Graphics: Canvas2D, defect)

Description

[Martijn Wargers (dead)]

Attachment: testcase

See testcase, it uses enhanced privileges, so you need to download it to your computer.

Canvas.drawWindow draws white for some reason after an onload event, while it just works fine if you use the method after the page has loaded.

Comment 1

[Boris Zbarsky [:bzbarsky]]

So our display list builder IsBackgroundOnly().  We should really unsuppress painting _before_ firing onload, shouldn't we?

Comment 2

[Boris Zbarsky [:bzbarsky]]

Alternately, we should ignore paint suppression for drawWindow or something.

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Yeah, I think we should.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Martijn, can you write the patch? Just make nsPresShell::RenderDocument set nsDisplayListBuilder's mIsBackgroundOnly to false, via a new setter method in nsDisplayListBuilder.

Comment 5

[Martijn Wargers (dead)]

Attachment: patch

The reftest getting checked in would depend on bug 448676 or related one being fixed.

Comment 6

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Comment on attachment 334119 [details] [diff] [review]
patch

I assume you tested this and it works :-)

Comment 7

[Boris Zbarsky [:bzbarsky]]

Pushed this, with the test disabled.  The test I added in bug 449781 handles testing this, but I think we should still get the reftests in.