1387892 - Content size error when flex-item is scrollable

Status: NEW

(Core :: Layout, defect, P3)

Description

[Daniel Brownlees]

Attachment: test_case.html

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170628075643

Steps to reproduce:

Open test case, reduce window height until container scrolls, enlarge window.  Note this also happens often when inserting content into the container dynamically.


Actual results:

Container remains overflowing even thought it is no longer constrained - refer screenshot.  The container width may need to be tweaked to reproduce depending on fonts. 

The content seems to wrap _after_ the content is sized, which then causes an overflow on the container.  The first <span> has been crafted to cause the issue, it will happen if there is a potential for extra wrapping anywhere in the container.


Expected results:

The container should grow to accommodate the content and not scroll.

Comment 1

[Daniel Brownlees]

Attachment: Screenshot of overflow on enlarged window

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: screencast of dholbert attempting & failing to reproduce

Hi! Thanks for the bug report. I tried to reproduce (with the width adjusted slightly so the first line wraps when the scrollbar appears), but I wasn't able to.

Here's a screencast of me trying on Linux, FWIW.  I tried on Mac as well (via BrowserStack remote-desktop) and was unable to reproduce there, too.

Any other tips for getting this to happen?  Perhaps you can come up with a simpler testcase that reproduces it for you & just has a few words (and a large font) or something, so that there are fewer moving parts?

Comment 3

[Daniel Brownlees]

I can reproduce on Linux (Ubunutu 17.04, Firefox 55.0.1 64bit) by either changing the theme with a new instance and opening the original test case:

~$ GTK_THEME=radiance firefox

or with test_case_2.html which is a slightly simplified layout.

This second test case will also reproduce for me on MacOS 10.12.6, FF54.0.1 (64-bit) with the container width at 180px - although that width may depend on fonts I think.

Comment 4

[Daniel Brownlees]

Attachment: test_case_2.html

Comment 5

[Daniel Brownlees]

Attachment: scroll error on linux.ogv

Screencast of error on Ubuntu 17.04, FF55.0.1 (64-bit) with test_case_2.html

Comment 6

[Daniel Holbert [:dholbert]]

Thank you! I can reproduce with test_case_2.html on Linux (Ubuntu 17.04), Firefox Nightly 57.0a1 (2017-08-15) (64-bit). I see the same results shown in your comment 5 screencast.

Comment 7

[Firefox Bug Husbandry Bot]

https://wiki.mozilla.org/Bug_Triage/Projects/Bug_Handling/Bug_Husbandry#Move_fix-optionals