Bug 148068

Summary: will-change should trigger stacking context based purely on properties
Product: WebKit Reporter: Simon Fraser (smfr) <simon.fraser>
Component: Layout and RenderingAssignee: Simon Fraser (smfr) <simon.fraser>
Status: RESOLVED FIXED    
Severity: Normal CC: bfulgham, buildbot, commit-queue, esprehn+autocc, glenn, jonlee, kondapallykalyan, rniwa, simon.fraser, webkit-bug-importer, zalan
Priority: P2 Keywords: InRadar
Version: 528+ (Nightly build)   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch
none
Patch
zalan: review+, buildbot: commit-queue-
Archive of layout-test-results from ews100 for mac-mavericks
none
Archive of layout-test-results from ews104 for mac-mavericks-wk2 none

Description Simon Fraser (smfr) 2015-08-16 12:21:19 PDT
I think will-change should only trigger stacking context when the element supports the changing property.

For example, will-change:transform should be a no-op on a <span>

It's not clear what <div style="will-change:z-index"> should do.
Comment 1 Simon Fraser (smfr) 2015-08-16 12:23:35 PDT
Started a thread here:
https://lists.w3.org/Archives/Public/www-style/2015Aug/0142.html
Comment 2 Simon Fraser (smfr) 2015-10-04 17:05:27 PDT
CSSWG disagreed.
Comment 3 Radar WebKit Bug Importer 2015-10-06 00:49:32 PDT
<rdar://problem/22986868>
Comment 4 Simon Fraser (smfr) 2015-10-06 21:54:28 PDT
Created attachment 262579 [details]
Patch
Comment 5 Simon Fraser (smfr) 2015-10-06 21:57:31 PDT
Created attachment 262581 [details]
Patch
Comment 6 Build Bot 2015-10-06 22:34:23 PDT
Comment on attachment 262581 [details]
Patch

Attachment 262581 [details] did not pass mac-ews (mac):
Output: http://webkit-queues.webkit.org/results/252843

New failing tests:
fast/css/will-change/will-change-creates-stacking-context-inline.html
Comment 7 Build Bot 2015-10-06 22:34:26 PDT
Created attachment 262582 [details]
Archive of layout-test-results from ews100 for mac-mavericks

The attached test failures were seen while running run-webkit-tests on the mac-ews.
Bot: ews100  Port: mac-mavericks  Platform: Mac OS X 10.9.5
Comment 8 Build Bot 2015-10-06 22:40:47 PDT
Comment on attachment 262581 [details]
Patch

Attachment 262581 [details] did not pass mac-wk2-ews (mac-wk2):
Output: http://webkit-queues.webkit.org/results/252849

New failing tests:
fast/css/will-change/will-change-creates-stacking-context-inline.html
Comment 9 Build Bot 2015-10-06 22:40:50 PDT
Created attachment 262583 [details]
Archive of layout-test-results from ews104 for mac-mavericks-wk2

The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews.
Bot: ews104  Port: mac-mavericks-wk2  Platform: Mac OS X 10.9.5
Comment 10 Simon Fraser (smfr) 2015-10-07 08:10:24 PDT
https://trac.webkit.org/changeset/190667
Comment 11 Alexey Proskuryakov 2015-10-07 21:57:09 PDT
fast/css/will-change/will-change-creates-stacking-context-inline.html fails on Windows too (of course).

Could you please add an expectation?
Comment 12 Brent Fulgham 2015-10-12 11:12:25 PDT
Test expectation for expected Windows failure (due to lack of backdrop-filter support) committed:

https://trac.webkit.org/changeset/190868.