1480636 - On fixed-size abspos table, margin:auto does not resolve (doesn't trigger vertical centering)

Status: RESOLVED WORKSFORME

(Core :: Layout: Tables, defect, P3)

Description

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

STR:
1. View attached testcase.

ACTUAL RESULTS:
The table box (the second one) is snapped to the top of its containing block.

EXPECTED RESULTS:
Both orange boxes should be vertically centered.


Chrome, OperaPresto, and Safari all give EXPECTED RESULTS.
Firefox gives ACTUAL RESULTS.


Note: this seems to be the underlying compat issue at https://github.com/webcompat/web-bugs/issues/17876 (which causes a little popup div to be top-aligned rather than center-aligned at a mobile site there)

Comment 1

[Daniel Holbert [:dholbert]]

(Edge agrees with Firefox here, interestingly... either they've got the same bug, or maybe there's some arcane justification for the Firefox/Edge behavior.)

Comment 2

[Dennis Schubert [:denschub]]

From the testcase in comment 0, Chrome, Safari, and Firefox agree now.

It looks like this is fixed now. Daniel, am I correct?

Comment 3

[Daniel Holbert [:dholbert]]

Yup, it looks like we fixed this; we produce EXPECTED RESULTS now.

mozregression says this was fixed in range https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0dbba4cd204153adcf3b8f09c1d27db056470599&tochange=cb97abb159426df201455523307964287956f8e0

Probably fixed by bug 799725 or bug 1692116. (Not sure which one is more likely to be the fix, at first glance.)

Leaving ni=me to make this test into a WPT test. (I don't think any of the testcases that landed in those^ likely-fix-bugs' commits seem to capture what the testcase here captures, i.e. abspos table with margin:auto.)

Comment 4

[Daniel Holbert [:dholbert]]

Attachment: Bug 1480636: Add a WPT test for margin:auto centering behavior of absolutely-positioned tables. r?#layout

The actual bug here was fixed by another commit from another bug. This patch is
just adding a WPT test to ensure we've got test coverage.

(In builds before the fix landed, e.g. Firefox Nightly 2021-01-01, this test
renders with the table placed too high up. This leaves some red visible and
covers up some of the descriptive text, which properly results in a
test-failure.)

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/6a0b05b41d72
Add a WPT test for margin:auto centering behavior of absolutely-positioned tables. r=emilio,TYLin

Comment 6

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/34509 for changes under testing/web-platform/tests

Comment 7

[Cristina Cozmuta (:CrissCozmuta)]

https://hg.mozilla.org/mozilla-central/rev/6a0b05b41d72

Comment 8

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 9

[Daniel Holbert [:dholbert]]

(In reply to Daniel Holbert [:dholbert] from comment #3)

Leaving ni=me to make this test into a WPT test.

[done]