1995284 - `position-try-fallbacks` code should distinguish between not having fallbacks to try vs. running out

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, enhancement)

Description

[David Shin[:dshin]]

Currently, we treat not having any fallbacks as running out of fallbacks if we're overflowing the containing block.

We need to make a distinction because we compute hypothetical scroll offsets for each fallback option, then roll back if we ran out of options to try.

Comment 1

[David Shin[:dshin]]

Attachment: Bug 1995284: When finishing abspos reflow, distinguish running out of fallbacks vs. not having any. r=#anchor-pos

No behavioural change currently, but distinguishing the two scenarios is
necessary to know to determine if we commit to the new scroll offset vs.
Roll back to what we started with.

Comment 2

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/ed73d3bdf859
https://hg.mozilla.org/integration/autoland/rev/51ae13a7e067
When finishing abspos reflow, distinguish running out of fallbacks vs. not having any.  r=layout-anchor-positioning-reviewers,layout-reviewers,emilio,jwatt

Comment 3

[amarc]

https://hg.mozilla.org/mozilla-central/rev/51ae13a7e067