tree 0c747d1f1e87ce7322742a392bd490a956019c43
parent 1b52416c81f5ff17ef313dd715a29f8f2f7d5854
author simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557612337 +0000
committer simon.fraser@apple.com <simon.fraser@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> 1557612337 +0000

Translucent gradient rendering bug due to will-change transform
https://bugs.webkit.org/show_bug.cgi?id=197654
<rdar://problem/50547664>

Reviewed by Dean Jackson.
Source/WebCore:

We failed to re-evaluate 'contentsOpaque' when a background changed, because this
happened in updateGeometry() and that doesn't run for background changes.

However, 'contentsOpaque' also requires knowing about geometry because we have to
turn it off when there's subpixel positioning, and updateConfiguration()
runs before updateGeometry().

So compute m_hasSubpixelRounding in updateGeometry() and set contentsOpaque in
updateAfterDescendants().

Test: compositing/contents-opaque/background-change-to-transparent.html

* rendering/RenderLayerBacking.cpp:
(WebCore::RenderLayerBacking::updateConfiguration):
(WebCore::RenderLayerBacking::updateGeometry):
(WebCore::RenderLayerBacking::updateAfterDescendants):
* rendering/RenderLayerBacking.h:

LayoutTests:

* compositing/contents-opaque/background-change-to-transparent-expected.txt: Added.
* compositing/contents-opaque/background-change-to-transparent.html: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@245207 268f45cc-cd09-0410-ab3c-d52691b4dbfc