983632 - [Australis, Windows HiDPI] button icons can be completely hidden but still be on toolbar and not in overflow menu if window resized/width decreased

Status: VERIFIED FIXED

(Firefox :: Toolbars and Customization, defect)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

Attachment: screenshot of issue

Nightly and Aurora 20140313 on Windows 8.1 Pro (OS level font size 125%)

When the browser window's width gets decreased, it is possible that the icon of a button gets completely hidden, but some of clickable area is still available (see screenshot).

In my humble opinion, the button should get added to the overflow. E.g. after the icon getting partially hidden, or at a threshold (like 50%).

Comment 1

[:Gijs (he/him)]

Can you provide STR? On OS X and Linux, we have a recent regression bug filed, where the QA person who reported it said it's not reproducible on Windows, so...

Comment 2

[:Gijs (he/him)]

(other bug is bug 983562)

Comment 3

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

(In reply to :Gijs Kruitbosch from comment #1)
> Can you provide STR?
1. Create new profile and launch it (window opens not maximized).
2. Reduce window width.

Comment 4

[:Gijs (he/him)]

Sigh.

Comment 5

[:Gijs (he/him)]

I expect this is a core bug with overflow events, considering that I can't reproduce on 100% DPI but can on 125% (and Jared reproduced on 200% DPI).

Comment 6

[:Gijs (he/him)]

Jared said he's looking at this. :-)

Comment 7

[Jared Wein [:jaws] (please needinfo? me)]

I looked for the regression range and this has been present since Australis merged to mozilla-central.
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=beddd6d4bcdf&tochange=ba9ecdea3a90

I think this has something to do with overflowing at a slow pace, because that's the only way that I can reproduce it. My guess is that our calculations for determining if something is overflowing don't trigger if it's only a couple pixels, whereas if you resize the window quickly then this bug doesn't appear.

Comment 8

[Jared Wein [:jaws] (please needinfo? me)]

Attachment: Patch

Comment 9

[Jared Wein [:jaws] (please needinfo? me)]

https://hg.mozilla.org/integration/fx-team/rev/d7e5a58a314d

Comment 11

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/d7e5a58a314d

Comment 12

[:Gijs (he/him)]

Comment on attachment 8391240 [details] [diff] [review]
Patch

[Approval Request Comment]
Bug caused by (feature/regressing bug #): Australis' overflowable toolbar
User impact if declined: sometimes the toolbar doesn't overflow correctly because we don't get overflow events
Testing completed (on m-c, etc.): on m-c
Risk to taking this patch (and alternatives if risky): very low
String or IDL/UUID changes made by this patch: none

NB: uplifting this is important if we uplift bug 980879.

Comment 13

[Matthew N. [:MattN]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/1ad262400852

Comment 14

[Bogdan Maris, Desktop QA]

Reproduced the initial issue on Surface Pro 2 (Windows 8.1 64bit) using Aurora from 2014-03-14, 125% and 200% DPI, verified as fixed using Firefox 29 RC and latest Aurora.