Closed Bug 1417055 Opened 4 years ago Closed 3 years ago

Scrolling over fixed-pos items might scroll the wrong frame

Categories

(Core :: Graphics: WebRender, defect, P1)

Other Branch
defect

Tracking

()

RESOLVED FIXED
Tracking Status
firefox57 --- unaffected
firefox58 --- unaffected

People

(Reporter: kats, Assigned: kats)

References

Details

(Whiteboard: [wr-reserve] [gfx-noted])

Attachments

(1 file)

Attached file testcase
Load attached testcase with webrender. Move the mouse over the red square and wheel-scroll.

Expected: nothing scrolls (as in non-webrender)
Actual: the subframe scrolls

The patchset I'm working on for bug 1389149 fixes this, but filing this as a separate bug to track it and ensure it gets fixed one way or another.
The reason this happens is that with non-WR, nsDisplayFixedPosition does one thing and then FrameLayerBuilder later fixes it up [1]. With WR we do the nsDisplayFixedPosition thing but then don't do the fixup so we end up with the wrong scroll target on the fixed-pos layer scroll data.

[1] https://searchfox.org/mozilla-central/rev/bab833ebeef6b2202e71f81d225b968283521fd6/layout/painting/FrameLayerBuilder.cpp#5010-5012,5029-5032
Attachment #8928156 - Attachment mime type: text/plain → text/html
Whiteboard: [gfx-noted][wr-mvp][triage] → [wr-mvp] [gfx-noted]
Priority: P2 → P3
Whiteboard: [wr-mvp] [gfx-noted] → [wr-reserve] [gfx-noted]
Depends on: 1421380
No longer depends on: 1389149
Assignee: nobody → bugmail
Priority: P3 → P1
Fixed by bug 1421380.
Status: NEW → RESOLVED
Closed: 3 years ago
Resolution: --- → FIXED
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