Open Bug 1326551 Opened 3 years ago Updated 3 years ago

Background rendering incomplete in (display: table-row) with (direction: rtl) on resize

Categories

(Core :: Layout, defect, P3)

41 Branch
defect

Tracking

()

Tracking Status
firefox50 --- wontfix
firefox51 --- wontfix
firefox52 --- wontfix
firefox53 --- wontfix
firefox54 --- fix-optional

People

(Reporter: mail, Unassigned)

References

()

Details

(Keywords: regression, testcase)

Attachments

(2 files)

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:50.0) Gecko/20100101 Firefox/50.0
Build ID: 20161209095719

Steps to reproduce:

0. Use Firefox on Ubunutu (latest from the Ubuntu repository, Firefox 50.1.0) - did not yet test this on other platforms
1. Create a table width DIVs, based on CSS display: table, table-row, table-cell
2. Gave one of the rows a background color
3. Set text direction: rtl (right-to-left)
4. Resized window very small (width) and then large again (depends on test case)


Actual results:

The background for the table row is not rendered completely (see screenshot). In a more complex layout (more rows) this also happens without resizing. The problem went worse when opening the developer console. Therefore, I assume it's a performance issue.

Please see attached screenshots for example.


Expected results:

The background should fill the whole table row.
OS: Unspecified → Linux
Hardware: Unspecified → x86_64
Coukd you just provide a testcase as html file like on jsfiddle or codepen, please.
Flags: needinfo?(mail)
Keywords: testcase-wanted
Ah .. JSFiddle is a good idea for that.

Here's the test case: https://jsfiddle.net/xgp50efy/
Please resize the output window small and then large again to see the issue.

(Tested with Firefox 50.1.0 under Ubuntu 16.04)
Keywords: testcase-wanted
Regression range:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=a38c23ccca0a&tochange=be81b8d6fae9

It could be a regression from bug 1169440.

David, what do you think?
Component: Layout: Block and Inline → Layout
Flags: needinfo?(mail) → needinfo?(dbaron)
Keywords: regression, testcase
Version: 50 Branch → 41 Branch
Seems much more likely to be a regression from bug 1174700 (also in that range).
Blocks: 1174700
Flags: needinfo?(dbaron) → needinfo?(jfkthame)
Status: UNCONFIRMED → NEW
Ever confirmed: true
OS: Linux → All
Hardware: x86_64 → All
(In reply to David Baron :dbaron: ⌚️UTC-8 from comment #4)
> Seems much more likely to be a regression from bug 1174700 (also in that
> range).

Yes, that'll surely be it.

Interesting that the testcase only exhibits the problem when the table cells have position:relative; if I remove that, I can no longer reproduce.

Another version of the issue: open the testcase (attachment 8823134 [details]), and use the Dev Tools inspector to look at the style of one of the table cells. Click the checkbox to disable the "position: relative" property on it: no visible change (as expected). Then click it again to re-enable the "position: relative" property: cell background disappears. Slightly resizing the window makes it reappear.
Flags: needinfo?(jfkthame)
Hi Jonathan, we looked at this in regression triage today. Is this bad enough to get an assignee (or a backout), or leave it for a later fix?
(In reply to David Bolter [:davidb] from comment #7)
> Hi Jonathan, we looked at this in regression triage today. Is this bad
> enough to get an assignee (or a backout), or leave it for a later fix?

It looks like this is limited to a pretty specific (and rare, I guess) combination of circumstances, and it's more of a cosmetic than a crippling failure, such that I don't think a backout is called for (and trying to back out bug 1174700 at this point would carry substantial risk of its own).

I wouldn't consider it a top priority, either, though it's certainly a valid bug we should fix.
Flags: needinfo?(jfkthame)
Too late for firefox 52, mass-wontfix.
Given comment 8 I'm letting this fall off of our weekly platform triage. Would it make a good first bug?
(In reply to Liz Henry (:lizzard) (needinfo? me) from comment #10)
> Given comment 8 I'm letting this fall off of our weekly platform triage.
> Would it make a good first bug?

Probably not; my gut feeling is that it's a layout issue that may be tricky to get right, and will depend on understanding reflow and frame coordinate management in some depth.
Priority: -- → P3
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