Bug 141537 - REGRESSION: Should not send wheel events with a delta of 0
Summary: REGRESSION: Should not send wheel events with a delta of 0
Status: RESOLVED FIXED
Alias: None
Product: WebKit
Classification: Unclassified
Component: Layout and Rendering (show other bugs)
Version: 528+ (Nightly build)
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Nobody
URL:
Keywords: InRadar, Regression
Depends on:
Blocks: 141821
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Reported: 2015-02-12 14:36 PST by Beth Dakin
Modified: 2015-02-19 18:13 PST (History)
8 users (show)

See Also:

Attachments
Patch (4.86 KB, patch)
2015-02-12 14:58 PST, Beth Dakin 		simon.fraser: review+
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Description Beth Dakin 2015-02-12 14:36:58 PST 
This is a regression from http://trac.webkit.org/changeset/172832/trunk/Source/WebCore/dom/Element.cpp We should not be sending wheel events to the DOM with a delta of 0. This affects webmail.apple.com

rdar://problem/18903118
Comment 1 Beth Dakin 2015-02-12 14:58:01 PST 
Created attachment 246478 [details]
Patch
Comment 2 Simon Fraser (smfr) 2015-02-12 15:05:38 PST 
Comment on attachment 246478 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=246478&action=review

> Source/WebCore/dom/Element.cpp:282
> +    if (!(event.deltaX() || event.deltaY()))

This would be clearer as if (!deltaX && !deltaY()) I think.
Comment 3 Beth Dakin 2015-02-12 15:09:38 PST 
http://trac.webkit.org/changeset/180018
Comment 4 Beth Dakin 2015-02-12 16:14:08 PST 
Re-baselined tests in: http://trac.webkit.org/changeset/180021
Comment 5 Brent Fulgham 2015-02-17 14:38:46 PST 
This change breaks snap scroll points, but you couldn't have known that since I have not gotten around to making suitable tests!
Comment 6 Beth Dakin 2015-02-17 14:42:50 PST 
(In reply to comment #5)
> This change breaks snap scroll points, but you couldn't have known that
> since I have not gotten around to making suitable tests!

I wonder why snap scroll points rely on getting a delta of 0?
Comment 7 Brent Fulgham 2015-02-17 14:47:40 PST 
(In reply to comment #6)
> (In reply to comment #5)
> > This change breaks snap scroll points, but you couldn't have known that
> > since I have not gotten around to making suitable tests!
> 
> I wonder why snap scroll points rely on getting a delta of 0?

I'm not sure. I'm debugging the code now to see why it matters. I think we have some kind of edge case where the user has ended the wheel motion and the snap animation is about to start. If we return 'false' in this case, the event is treated as unhandled and the animation never starts.

I'll know more once I finish debugging.