1001233 - "ASSERTION: writing-mode mismatch" with li::-moz-list-bullet { direction: rtl; }

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Jesse Ruderman]

Attachment: testcase

(Another assertion like in bug 986899)

###!!! ASSERTION: writing-mode mismatch: 'aWritingMode == mWritingMode', file WritingModes.h, line 732

Comment 1

[Jesse Ruderman]

Attachment: stack

Comment 2

[Simon Montagu :smontagu]

Attachment: Patch

This patch prevents the assertions. I'm not quite sure if the rendering is correct, but I don't think this is a case we really have to care about in the real world.

Comment 3

[Jonathan Kew [:jfkthame]]

Comment on attachment 8420652 [details] [diff] [review]
Patch

Review of attachment 8420652 [details] [diff] [review]:
-----------------------------------------------------------------

::: layout/generic/nsBlockFrame.cpp
@@ +6879,5 @@
> +  LogicalRect logicalFAS(blockWM, floatAvailSpace, containerWidth);
> +  nscoord iStart = logicalFAS.IStart(blockWM) -
> +                   rs.ComputedLogicalBorderPadding().IStart(blockWM) -
> +                   reflowState.ComputedLogicalMargin().IEnd(bulletWM) -
> +                   aMetrics.ISize();

No, this can't be right - it's arithmetically combining logical coordinates in (potentially) different writing modes, which is meaningless.

The error becomes visible, for example, if you add some content to the testcase and include
  margin-right:1em;
to the li::-moz-list-bullet style: the margin fails to show up to the right of the bullet.

Comment 4

[Jonathan Kew [:jfkthame]]

Attachment: convert bullet frame's margin to the block frame's writing mode when positioning bullet.

Here's what I think we actually need to do in this case.

Comment 5

[Jonathan Kew [:jfkthame]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/1e15bbf34b27

Comment 6

[Jonathan Kew [:jfkthame]]

The faulty code here was part of patch 1 in bug 789096, and as such it's now on aurora and beta branches as well. So we should consider uplifting the fix here once it's safely in Nightly.

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/1e15bbf34b27

Comment 8

[Jonathan Kew [:jfkthame]]

Comment on attachment 8420916 [details] [diff] [review]
convert bullet frame's margin to the block frame's writing mode when positioning bullet.

[Approval Request Comment]
Bug caused by (feature/regressing bug #): 789096 (patch 1)

User impact if declined: Possibility of misplaced or missing bullets in (unusual) bidi cases.

Testing completed (on m-c, etc.): Landed on m-c; includes testcase.

Risk to taking this patch (and alternatives if risky): Minimal risk: there's no security issue involved here, AFAICS, only the possibility of the bullet being placed wrongly. Patch is extremely localized and does not affect anything else apart from positioning of the bullet frame.

String or IDL/UUID changes made by this patch: none

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/ceff945c64ce
https://hg.mozilla.org/releases/mozilla-beta/rev/542398357372

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-b2g30_v1_4/rev/542398357372