1754598 - Block frame with definite block-size requests extra continuation of zero block-size in a small block-size multicol

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: testcase 1

See the attached testcase 1.

In a multicol container with a very small block-size, there is a simple unbreakable block with a definite block-size. We create an extra continuation even if it runs out of its block-size in the first column. It's invisible unless the unbreakable has outline for example.

I suspect we use a wrong nsReflowStatus in nsBlockFrame::ComputeFinalBSize.
https://searchfox.org/mozilla-central/rev/c12a59323ee46b29b90c9917a3a7a70ea714ffec/layout/generic/nsBlockFrame.cpp#7764-7784

Comment 1

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 1754598 Part 1 - Pass BlockReflowInput into nsBlockFrame::ComputeFinalBSize().

ComputeFinalBSize() gets most of its input parameters from BlockReflowInput's
members. Passing BlockReflowInput into it directly so that it can access more
precomputed data in BlockReflowInput such as ContentBEnd().

This is a preparation for the next part that is going to rewrite a large portion
of ComputeFinalBSize().

Comment 2

[Ting-Yu Lin [:TYLin] (PST, UTC-8)]

Attachment: Bug 1754598 Part 2 - Fix block frame's block-size and reflow status in ComputeFinalBSize().

The code at the end of ComputeFinalBSize() does not handle
"box-decoration-break:clone" and the cases where the block frame's reflow status
can change from incomplete to complete. This patch is an attempt to fix all the
possible scenarios.

Depends on D138966

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/049e60e0ba2c
Part 1 - Pass BlockReflowInput into nsBlockFrame::ComputeFinalBSize(). r=dholbert
https://hg.mozilla.org/integration/autoland/rev/bde7633d8c5c
Part 2 - Fix block frame's block-size and reflow status in ComputeFinalBSize(). r=dholbert

Comment 4

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/32912 for changes under testing/web-platform/tests

Comment 5

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/049e60e0ba2c
https://hg.mozilla.org/mozilla-central/rev/bde7633d8c5c

Comment 6

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

Upstream PR merged by moz-wptsync-bot