1465997 - Don't replace FontFaceSet's ready Promise when it's pending

Status: RESOLVED FIXED

(Core :: Layout, defect, P2)

Description

[Jonathan Watt [:jwatt]]

Right now the code in FontFaceSet::DispatchLoadingEventAndReplaceReadyPromise replaced mReady without regard for whether that Promise is resolved or not. That means that if there are any listeners of the replaced Promise, they will be listening to a Promise that is never resolved! Clearly that has the potential to break code.

Comment 1

[Jonathan Watt [:jwatt]]

In fact the only reason that we fail tests like web-platform/tests/css/css-fonts/variations/font-weight-matching.html.ini rather than timing out is because bug 1465983 causes the abandoned Promise to be resolved immediately as soon as it's constructed. (So we need to fix this bug before we can land the fix for bug 1465983.)

Comment 2

[Jonathan Watt [:jwatt]]

Attachment: patch

Comment 3

[Cameron McCormack (:heycam)]

Comment on attachment 8982375 [details] [diff] [review]
patch

Review of attachment 8982375 [details] [diff] [review]:
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r=me but if it's possible to add a WPT test for this, can you?

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/b1c533ccce56
Don't replace FontFaceSet's ready Promise when it's pending. r=heycam

Comment 5

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/b1c533ccce56