1235489 - "Assertion failure: !StyleText()->HasTextEmphasis()" when simultaneously changing zoom and calling canvas.drawWindow(DRAWWINDOW_DO_NOT_FLUSH)

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Jesse Ruderman]

Attachment: testcase (requires pref & extension)

Assertion failure: !StyleText()->HasTextEmphasis(), at layout/generic/nsTextFrame.cpp:6207

Comment 1

[Jesse Ruderman]

Attachment: stack

Comment 2

[Jesse Ruderman]

To reproduce you'll need a Firefox profile with the pref:
    user_pref("layout.css.text-emphasis.enabled", true);
And the extension:
    https://github.com/MozillaSecurity/funfuzz/tree/master/dom/extension

Running `funfuzz/dom/automation/domInteresting.py <firefox-build> w.html` is the simplest way to get both.

Comment 3

[Xidorn Quan [:xidorn] UTC+10]

I don't understand this issue. Changing text-emphasis-style should triggers a reflow, which will update EmphasisMarkInfo properly and thus this assertion wouldn't be broken.

This issue means, it is valid to force a repaint without a reflow even if the style change requires? That sounds pretty dangerous in general.

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Reflow is interruptible, so in the case of a long running reflow that we interrupt, you certainly can't assume that we will reflow between a style change and a paint.

Comment 5

[Xidorn Quan [:xidorn] UTC+10]

Oh, okay. If that's the case, I think we can just remove that assertion.

Comment 6

[Xidorn Quan [:xidorn] UTC+10]

I thought interruptible reflow is only for script execution. Painting with a half-reflowed frame tree still sounds crazy... Hopefully frame reconstruction and the following first reflow wouldn't be interruptible...

Comment 7

[Xidorn Quan [:xidorn] UTC+10]

Attachment: MozReview Request: Bug 1235489 - Remove assertion which is breakable when reflow is interrupted.

Review commit: https://reviewboard.mozilla.org/r/29127/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/29127/

Comment 8

[Jonathan Kew [:jfkthame]]

Comment on attachment 8702534 [details]
MozReview Request: Bug 1235489 - Remove assertion which is breakable when reflow is interrupted.

https://reviewboard.mozilla.org/r/29127/#review26003

Comment 9

[Xidorn Quan [:xidorn] UTC+10]

https://hg.mozilla.org/integration/mozilla-inbound/rev/e779e01003e891cbbd6919aae279359120374efd
Bug 1235489 - Remove assertion which is breakable when reflow is interrupted. r=jfkthame

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/e779e01003e8