1980143 - Prevent generating backdrop pseudos for non-elements.

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect)

Comment 1

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1980143 - Prevent generating ::backdrop pseudo-elements for non-elements. r=keithamus,#style,#vt

Bug 1954142 causes some crashes in view transition pseudo-elements.

These happen because we create the ::-moz-snapshot-containing-block
pseudo-element in the top layer, then try to create a ::backdrop for it.

With the patches for that bug, such a
::-moz-snapshot-containing-block::backdrop pseudo-element wouldn't match
regular ::backdrop rules (that's per spec), causing backdrop frame to
not be in the top layer itself.

We don't need to generate backdrop frames for view transitions, and we
don't put other pseudo-elements in the top layer, so this doesn't change
behavior, but fixes the crashes that prevent bug 1954142 from landing.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/ca50a88faeee
https://hg.mozilla.org/integration/autoland/rev/534e5fd7c312
Prevent generating ::backdrop pseudo-elements for non-elements. r=dshin

Comment 3

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/534e5fd7c312