1043163 - "ASSERTION: Bad layer contents rectangle" with hugely negative transform scale

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Jesse Ruderman]

Attachment: testcase

###!!! ASSERTION: Bad layer contents rectangle: 'aLayerContentsVisibleRect->width >= 0 && aLayerContentsVisibleRect->height >= 0', file layout/base/FrameLayerBuilder.cpp, line 1753

This assertion was added in https://hg.mozilla.org/mozilla-central/rev/cb7751fa7b29

Comment 1

[Jesse Ruderman]

Attachment: stack

Comment 2

[Robert O'Callahan (:roc) (email my personal email if necessary)]

This is just a straight overflow in "pixBounds = state.ScaleToOutsidePixels(bounds, false);" because the Y scale is super-large. We end up with a negative height in pixBounds which later leads to the assertion.

Comment 3

[Robert O'Callahan (:roc) (email my personal email if necessary)]

I think we should probably just have the nsRect Scale methods clamp negative width/height to 0.

Comment 4

[Robert O'Callahan (:roc) (email my personal email if necessary)]

Attachment: Avoid negative widths and heights due to overflow

Comment 6

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/a5d5b4c5c24f