1396840 - [W10] White border displayed around Firefox after maximizing

Status: NEW

(Core :: Widget: Win32, defect, P3)

Description

[Ciprian Georgiu [:ciprian_georgiu], Release Desktop QA]

Attachment: border - screenshot.png

[Affected versions]:
- latest Nightly 57.0a1
- Beta 56.0b9
- RC 55.0.3

[Affected platforms]:
- Windows 10 x64

[Prerequisites]:
- a high dpi monitor, I used Dell UHD-1 P2415Qb

[Steps to reproduce]:
1. Start Firefox.
2. Double click on the tab bar in order to maximize Firefox (or use the square button).

[Expected result]:
- No white borders/artifacts displayed around Firefox.

[Actual result]:
- White borders displayed around Firefox and sometimes bluish artifacts in the right side of the Menu button (see the attached screenshot).

[Regression range]:
- Last good revision: 14593086470494abab1401eba9304defa715170e
  First bad revision: c3771535a47ebb8260de3362188c83790831867e
  Pushlog:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=14593086470494abab1401eba9304defa715170e&tochange=c3771535a47ebb8260de3362188c83790831867e

Looks like the following bug has the changes which introduced the regression:
https://bugzilla.mozilla.org/show_bug.cgi?id=1289143

[Additional notes]:
- specific to Windows 10 and not repro with a lower dpi monitor

Comment 1

[:Gijs (he/him)]

Given the regressing bug was in widget::win32 and the patch changed code there, I don't see how this would be a Fx::theme issue, so moving back to widget.

Jonathan or Jim, can you take a look, or, if you're already sure this is a theme issue, can you add some clarification as to what the issue is?

Ciprian, is nightly 58 still affected?

Comment 2

[Jonathan Kew (:jfkthame)]

I'm guessing this may also be related to the border scaling issues discussed in bug 1403153.

Although we've tried to fix something like this before, I think there are still certain cases (not sure exactly what...) where widget code gets incorrectly scaled metrics for window border elements, perhaps related to running Firefox on a screen with different DPI settings from the system's primary display, and/or after dynamic changes to system configuration. (Windows doesn't always handle on-the-fly changes very well; sometimes logging out of Windows and then back in, after a change such as connecting or disconnecting an external display, may be needed before the new configuration fully takes effect.)

So I do think this is probably a Widget:Win32 bug, though it's possible that Firefox theme changes could make it more or less apparent in some cases, depending how window borders (if any) are handled.

Comment 3

[Ciprian Georgiu [:ciprian_georgiu], Release Desktop QA]

(In reply to :Gijs from comment #1)
...
> Ciprian, is nightly 58 still affected?

Yes, it's still reproducible on latest Nightly 58.0a1, if the display scale factor it's set to 175%, 200% (recommended in my case) or 250% on Windows 10.

Comment 4

[:Gijs (he/him)]

I just realized that I can reproduce this on my main dev machine, running current windows insider win10. What can I do to debug? There's only ever 1 connected display (using 175% dpi, 2176 x 1224 on the standard issue dell hidpi screen) on this (desktop) machine, and this happens on both 57 and nightly, including a local build.

Comment 5

[:Gijs (he/him)]

Brindusa, can you do a similar check as in bug 1405593 comment #28 to see what versions of Windows are affected for this bug?

Comment 6

[Brindusa Tot[:brindusat]]

I could not reproduce this on any machine I tried, Windows 10 with versions:
 - Version 1511 (OS Build 10586.1106)
 - Version 1607 (OS Build 14393.1770)
 - Version 1703 (OS Build 15063.608)

I tried on a Windows 10 Version 1703 (OS Build 15063.674) connected to a HPDI monitor and could not reproduce it.

Also, talk with Ciprian, and he still can reproduce this issue on Windows 10 Version 1607 (OS Build 14393.1715) connected to a HDPI monitor.

Comment 7

[:Gijs (he/him)]

(In reply to Brindusa Tot[:brindusat] from comment #6)
> I tried on a Windows 10 Version 1703 (OS Build 15063.674) connected to a
> HPDI monitor and could not reproduce it.
> 
> Also, talk with Ciprian, and he still can reproduce this issue on Windows 10
> Version 1607 (OS Build 14393.1715) connected to a HDPI monitor.

What DPI settings do the respective HIDPI monitors have, and are they the only monitors or are either/both machines using a multi-monitor setup?

Comment 8

[Ciprian Georgiu [:ciprian_georgiu], Release Desktop QA]

(In reply to :Gijs (slow, PTO recovery mode) from comment #7)
> (In reply to Brindusa Tot[:brindusat] from comment #6)
> > I tried on a Windows 10 Version 1703 (OS Build 15063.674) connected to a
> > HPDI monitor and could not reproduce it.
> > 
> > Also, talk with Ciprian, and he still can reproduce this issue on Windows 10
> > Version 1607 (OS Build 14393.1715) connected to a HDPI monitor.
> 
> What DPI settings do the respective HIDPI monitors have, and are they the
> only monitors or are either/both machines using a multi-monitor setup?

The monitor has a 200% DPI scaling set and a resolution of 3840 x 2160. I'm using 2 monitors connected to a PC, the HIDPI one is a Dell UHD-1 P2415Q and the low dpi monitor is a WSXGA Samsung 2233.

Comment 9

[Ryan VanderMeulen [:RyanVM]]

Is this still reproducible?

Comment 10

[Ciprian Georgiu [:ciprian_georgiu], Release Desktop QA]

(In reply to Ryan VanderMeulen [:RyanVM] from comment #9)
> Is this still reproducible?

Yes, I can still reproduce this bug on latest Nightly 60.0a1 (2018-01-23) on Win 10 x64.

Comment 12

[jezze]

Is 1483448 a duplicate?

Still occurs in the latest Beta 65.0 on Windwos 10.

• 3 monitors
• two at 1920 x 1080
• one at 3840 x 2160 with 300% DPI

A temorary workaround is to uninstall Firefox, complete delete the installation folder, performe a Windwos Disk Cleanup, restart Windows and reinstall Firefox. However the border will come back after a while.

https://support.mozilla.org/de/questions/1197359