1731653 - {inc} On horizontal resize, we don't correctly resize block with box-sizing: content-box, percentage width, and percentage padding

Status: VERIFIED FIXED

(Core :: Layout, defect)

Description

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: testcase.html

While working on bug 1700580, I discover an invalidation issue where we don't trigger reflow for a block with box-sizing: content-box, percentage width, and percentage padding if we change its container's width.

See the attached testcase.

Comment 1

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: WIP: Bug 1731653 - Mark a frame as IResize if its border-box is not changed but it has percentage padding.

The issue in dynamic-isize-change-005.html is that during the flex
item's incremental reflow, its CachedBAxisMeasurement does being
rejected due to its inline-size changed. However, it is not properly
marked as IResize in ReflowInput::InitResizeFlags(), so the flex
item (block frame) thinks its lines are clean and not bother reflowing
them.

To fix this, we can simply remove the condition that tests the frame's
box-sizing property because it has nothing to do with whether its
content-box size is changed or not. dynamic-isize-change-005.html is an
example where a flex item has the same border-box inline size, but
changes its content-box inline-size due to different flex container's
inline-size.

Comment 2

[Ting-Yu Lin [:TYLin] (PDT, UTC-7)]

Attachment: Bug 1731653 - Record padding change in a frame bit, and use it to detect inline resize.

We store this new bit in nsIFrame instead of in ReflowInput to record a
change to padding (inspired by the mHasBSizeChange bit). That is because
we may construct a ReflowInput more than one time before reflowing the
frame. The first construction of ReflowInput (in
SizeComputationInput::InitOffsets will update
nsIFrame::UsedPaddingProperty() using the latest style data, so
we cannot determine the padding change in any of the subsequent
construction of ReflowInput.

dynamic-change-inline-size-001.html is the scenario fixed by bug
1307853.

dynamic-change-inline-size-002.html is equivalent to 001.html except
it's written with "box-sizing:content". It is fixed by this patch.

dynamic-change-inline-size-003.html is adapted from testcase 2 in bug
1729122 comment 4.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8cb9446b8382
Record padding change in a frame bit, and use it to detect inline resize. r=dholbert

Comment 4

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/8cb9446b8382

Comment 6

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

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/31053 for changes under testing/web-platform/tests

Comment 7

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

Upstream PR merged by moz-wptsync-bot

Comment 8

[Cristian Fogel [:cfogel]]

Confirmed issue with 94.0a1 (2021-09-20) on Win10.
Fix verified with 95.0a1 (2021-10-06) and 94.0b2 on Win10 and Ubuntu 16x32.

Comment 9

[Mihai Boldan, Desktop QA [:mboldan]]

Based on Comment 8, I'm marking this issue as Verified Fixed.