Closed Bug 951320 Opened 10 years ago Closed 10 years ago

The requested displayport is sometimes wider than the page


(Core :: Panning and Zooming, defect)

Gonk (Firefox OS)
Not set



Tracking Status
firefox27 --- unaffected
firefox28 --- fixed
firefox29 --- fixed
b2g-v1.2 --- unaffected
b2g-v1.3 --- fixed


(Reporter: kats, Assigned: kats)



(Keywords: regression, Whiteboard: [beta28] p=0)


(1 file)

Doing some rendertrace logging on the peak in the settings app showed that the displayport being requested was sometimes 540 pixels wide even though the page was only 360 pixels wide.

Turns out GetExpandedScrollableRect doesn't bother to convert the composition bounds from a ScreenRect to a CSSRect. The composition bounds isn't always correct (bug 935219) but even so expanding the scrollable rect by a ScreenRect composition bounds is wrong.
Attached patch PatchSplinter Review
This fixes the issue, but I need to test it more to ensure there aren't any other bad side-effects.
Assignee: nobody → bugmail.mozilla

Requesting uplift to 1.3. There are no user-visible bad effects from this bug, but I suspect it might result in wasted memory usage because the displayport is larger than it should be. I'm not actually sure if the texture that gets created is larger or not though.
blocking-b2g: --- → 1.3?
Doh. This is actually a regression introduced very recently in bug 949404.
Whiteboard: [beta28]
Whiteboard: [beta28] → [beta28] p=0
Closed: 10 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla29
Blocks: metrov1it21
No longer blocks: metrov1backlog
Comment on attachment 8348953 [details] [diff] [review]

[Approval Request Comment]
Bug caused by (feature/regressing bug #): bug 949404
User impact if declined: panning around on some pages is very janky in metrofox (see bug 951751)
Testing completed (on m-c, etc.): locally
Risk to taking this patch (and alternatives if risky): low risk, very obvious fix for the regression. affects only b2g and metro
String or IDL/UUID changes made by this patch: none
Attachment #8348953 - Flags: approval-mozilla-aurora?
Attachment #8348953 - Flags: approval-mozilla-aurora? → approval-mozilla-aurora+
Already in 1.3 per comment 7, so clearing nom.
blocking-b2g: 1.3? → ---
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