1786284 - Improve handling of anomalous tables in COLR font code

Status: RESOLVED FIXED

(Core :: Layout: Text and Fonts, defect)

Description

[Jonathan Kew [:jfkthame]]

In the initial COLRv1 implementation, I left MOZ_ASSERT_UNREACHABLE assertions at various places when we encounter cases that should never exist in valid fonts. However, as we handle these anomalies safely, the assertions aren't really needed and just create noise in testing.

There are also some cases where we can pre-emptively bail out of processing a table, such as when a relative paintOffset field is zero; this can never be valid as it would lead to infinite self-recursion.

Comment 1

[Jonathan Kew [:jfkthame]]

Attachment: Bug 1786284 - Improve handling of errors in COLRv1 font tables. r=#gfx-reviewers

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7cc5332b0fdf
Improve handling of errors in COLRv1 font tables. r=gfx-reviewers,lsalzman

Comment 3

[Norisz Fay [:noriszfay]]

Backed out for causing build bustage on COLRFonts.cpp

Backout link

Push with failures

Failure log

Failure line: /builds/worker/checkouts/gecko/gfx/thebes/COLRFonts.cpp:1680:10: error: 'return' will never be executed [-Werror,-Wunreachable-code-return]

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7883889e8974
Improve handling of errors in COLRv1 font tables. r=gfx-reviewers,lsalzman

Comment 5

[Marian-Vasile Laza]

https://hg.mozilla.org/mozilla-central/rev/7883889e8974