1819525 - On Windows11, Firefox shows one pixel line at bottom in Maximized sizemode when taskbar is set to "Auto Hide" if enabled browser.tabs.inTitlebar

Status: RESOLVED DUPLICATE of bug 642851

(Core :: Widget: Win32, defect, P2)

Description

[spyda.bird]

Attachment: FIREFOX LINE.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/110.0

Steps to reproduce:

1 Open a page with dark areas or images.
2 Maximize Firefox.
3. Set taskbar to automatically hide in Taskbar Behaviour Settings.
4. Scroll down until an image or dark area is bordering the bottom of the screen and you should see a 1 pixel line overlaying that area
May require a light desktop background if so obviously reverse the shades in these steps if you have a dark desktop background.
I also have Windows mode set to dark and app mode set to light with a dark taskbar and light desktop background.

Actual results:

A white line overlays the bottom horizontal row of pixels.

Expected results:

There should not be a white line overlaying content at the bottom of the page.

Comment 1

[spyda.bird]

The Windows update that removed the one pixel line when hiding the taskbar was -
(KB5022913)

Comment 2

[spyda.bird]

I should have added I am using Windows 11 Pro, 22H2.

Comment 4

[spyda.bird]

I just uninstalled update (KB5022913) from yesterday and the white line is gone.
This is not a duplicate of bug 1802721 it is a new bug with similar symptoms.

Comment 5

[Alice0775 White]

I can reproduce the issue on Windows11.
The 1px line appears. And, the line color is always white, regardless of the color of the taskbar.

Comment 6

[Alice0775 White]

Enabling Title Bar from Customize toolbar will fix this problem.

Comment 7

[Alice0775 White]

About Windows10, See Bug 1802721.

Comment 8

[jfryton]

Oddly this issue seems to be intermittent. The white line sometimes disappears at random and just as unexpectedly reappears. Enabling the title bar does hide it, but only while the option is enabled.

Can confirm while the issue is occurring, it is present in both Firefox and Librewolf. Reinstallation does not make a difference. Nothing else seems to have this issue (e.g., Chrome, Brave, Explorer, and others do not have the white line).

Considering I'm using an OLED display, I'll have to switch to Brave until the issue is resolved.

Comment 9

[jfryton]

(In reply to Alice0775 White from comment #6)

Enabling Title Bar from Customize toolbar will fix this problem.

It did for me the first time, but I tried it again and the white line is still there. A reboot seemed to temporarily remove the white line for me. Very odd.

Comment 10

[Emilio Cobos Álvarez (:emilio)]

FWIW the windows terminal has a similar issue, but instead of a white line it is transparent and shows the desktop background.

Comment 12

[stefank.android]

I can confirm that I am experiencing the exact same behaviour as jfryton. The bug only appears when taskbar is set to auto-hide. It is an intermittent issue. I have not been able to figure out what causes it to appear/disappear. It's possible that it "disappears" when the screen pixel shifts (OLEDs will move the image a few pixels after a set amount of time). The line always returns.

This problem does not appear on any Chromium browsers. Tested on Chrome, Edge, and Brave.

Right now, I'm forced to use Brave as the bright white line in FF is a burn-in source.

Comment 13

[mbattjes]

(In reply to stefank.android from comment #12)

I can confirm that I am experiencing the exact same behaviour as jfryton. The bug only appears when taskbar is set to auto-hide. It is an intermittent issue. I have not been able to figure out what causes it to appear/disappear. It's possible that it "disappears" when the screen pixel shifts (OLEDs will move the image a few pixels after a set amount of time). The line always returns.

This is not an intermittent issue. Your hypothesis about pixel shift is correct. If you turn it off you will always see the white line. I think this should have higher priority. It's bad for OLED displays and very annoying on dark websites or full screen videos.

Comment 14

[spyda.bird]

I have to agree with mbattjes - After using Firefox for years this is the first time a bug has actually forced me to use another browser -
I'm not sure the devs get how bad this is -
Here's an example (Sorry I zoomed away from the white line with the magnifier a couple of times)
Have to watch in full screen at 4K resolution ideally -
https://www.youtube.com/watch?v=fco1UvdayCk

Comment 15

[Kestrel]

Users concerned with OLED burn-in should not be using maximized windows, you need to avoid all static elements which means using floating windows, cycling wallpaper and an empty desktop. Burn-in is much more of a concern in central areas of the screen, losing brightness in the last row of pixels on the bottom edge would be barely noticeable, especially at 4K resolution. If the line was black it would be worse for most users that use light mode since it would eventually make those pixels brighter (less worn).

Comment 16

[mbattjes]

(In reply to Kestrel from comment #15)

Users concerned with OLED burn-in should not be using maximized windows, you need to avoid all static elements which means using floating windows, cycling wallpaper and an empty desktop. Burn-in is much more of a concern in central areas of the screen, losing brightness in the last row of pixels on the bottom edge would be barely noticeable, especially at 4K resolution. If the line was black it would be worse for most users that use light mode since it would eventually make those pixels brighter (less worn).

I agree the burn-in from a single line of pixel at the bottom of the screen is a minor issue. But the annoyance is very real, especially on videos.
I don't understand how you can say you should not be using maximized windows to avoid burn-in. It removes all of the static elements of the browser, which is exactly what you want. In fact cycling wallpapers and empty desktop don't matter because you should have a blank screensaver that triggers within 5 minutes anyway.

Comment 17

[Kestrel]

The standard maximized browser interface has a fixed toolbar with many static elements. Fullscreen mode (F11) with auto-hiding toolbar and fullscreen video are not affected by this bug with a clean configuration (note the taskbar does not show in fullscreen mode).

The line color can be changed to the window border color with the following userChrome.css:

#main-window[tabsintitlebar][sizemode="maximized"] {
  appearance: -moz-win-borderless-glass;
}

Comment 18

[spyda.bird]

Kestrel -

The line color can be changed to the window border color with the following userChrome.css:

#main-window[tabsintitlebar][sizemode="maximized"] {
appearance: -moz-win-borderless-glass;
}

This does not make any difference for me and I'm not sure what you mean by

window border color

Comment 19

[spyda.bird]

(In reply to Kestrel from comment #15)

Users concerned with OLED burn-in should not be using maximized windows

You might as well just say "Should not be using Windows"

Losing brightness in the last row of pixels on the bottom edge would be barely noticeable, especially at 4K resolution.

I think people would rather have this fixed than damage their $3000 OLEDs.

Comment 20

[mbattjes]

(In reply to Kestrel from comment #17)

The standard maximized browser interface has a fixed toolbar with many static elements. Fullscreen mode (F11) with auto-hiding toolbar and fullscreen video are not affected by this bug with a clean configuration (note the taskbar does not show in fullscreen mode).

The line color can be changed to the window border color with the following userChrome.css:

#main-window[tabsintitlebar][sizemode="maximized"] {
  appearance: -moz-win-borderless-glass;
}

Of course we are only talking about Fullscreen mode here, where the task bar is not visible except for the white line. I'll try the css edit but i'm not sure if this line is the window border. It may be an invisible task bar border made visible.

Comment 21

[Alice0775 White]

Interestingly, if part of the original window extends beyond the bottom edge of the screen, the white line will be hidden when maximized.
See screencast https://youtu.be/GOqjXDZjPEk .

Comment 22

[spyda.bird]

(In reply to Alice0775 White from comment #21)

Interestingly, if part of the original window extends beyond the bottom edge of the screen, the white line will be hidden when maximized.
See screencast https://youtu.be/GOqjXDZjPEk .

I reproduced this behaviour immediately with my first attempt, but it only worked once and now the white line is there if I drag the window below the screen bottom and maximise.
The workaround I have been using is to add a full screen button to the toolbar and add -

:root[inFullscreen] #PersonalToolbar {
visibility: visible !important;
}
To userchrome.css and
browser.fullscreen.autohide set to False in about:config -
This makes Firefox look and behave identically to a maximised instance but to access the taskbar, Start, Explorer etc you have to tap the fullscreen button added to the toolbar -

Comment 23

[jfryton]

Quite disappointing to see this being given a relatively low priority. Like others, this is the first bug that has driven me to alternative browsers in many years. I'm also surprised to learn Microsoft Edge actually allows you to disable all of their telemetry while providing functionality to reduce background tab processes and isolate them for security. Bing sidebar is surprisingly useful for automatically summarizing webpages too.

Can also confirm it's not intermittent but was in fact the OLED pixel shifting trying to mitigate wear. Line appears consistently when streaming the PC via Moonlight. Doesn't happen for any other application I've tried.

Comment 24

[mbattjes]

:root[inFullscreen] #PersonalToolbar {
visibility: visible !important;
}

This did nothing for me

#main-window[tabsintitlebar][sizemode="maximized"] {
  appearance: -moz-win-borderless-glass;
}

Worked for changing to color of the line to the window color, which is much darker!

Comment 25

[spyda.bird]

(In reply to mbattjes from comment #24)

:root[inFullscreen] #PersonalToolbar {
visibility: visible !important;
}

This did nothing for me

#main-window[tabsintitlebar][sizemode="maximized"] {
  appearance: -moz-win-borderless-glass;
}

Worked for changing to color of the line to the window color, which is much darker!

You have to do all three things or it won't do anything -
The css, the about:config and add the fuulscreen button to the toolbar.
Then when you push the fullscreen button the white line will be gone but it will still appear to be maximised.

Comment 26

[Ray Kraesig [:rkraesig]]

(In reply to jfryton from comment #9)

It did for me the first time, but I tried it again and the white line is still there. A reboot seemed to temporarily remove the white line for me. Very odd.

(In reply to mbattjes from comment #13)

This is not an intermittent issue. Your hypothesis about pixel shift is correct. If you turn it off you will always see the white line. I think this should have higher priority. It's bad for OLED displays and very annoying on dark websites or full screen videos.

This actually does appear to be a quasi-intermittent issue with behavior not explicable by OLED pixel shift. If you take a screenshot, the one-pixel line always shows up, but it's not always the same color — without making any changes to Firefox beyond a restart, I have so far captured lines colored #ffffff and #2b2a33 (the latter being Firefox's dark-mode default homepage's background color).

(I assume that's what mbattjes is seeing in comment #24, although I haven't looked too closely at that CSS yet.)

Comment 27

[mbattjes]

I did the CSS mod and the color changes for me based on the Windows 'accent color', which is set to automatic and changes based on my background (which automatically changes as well).
Before the mod i did not notice any color changes, it was always white.

Comment 28

[Ray Kraesig [:rkraesig]]

(In reply to mbattjes from comment #27)

I did the CSS mod and the color changes for me based on the Windows 'accent color', which is set to automatic and changes based on my background (which automatically changes as well).
Before the mod i did not notice any color changes, it was always white.

Does this remain true if you demaximize ("restore") and then remaximize the window?

Comment 29

[mbattjes]

(In reply to Ray Kraesig [:rkraesig] from comment #28)

(In reply to mbattjes from comment #27)

I did the CSS mod and the color changes for me based on the Windows 'accent color', which is set to automatic and changes based on my background (which automatically changes as well).
Before the mod i did not notice any color changes, it was always white.

Does this remain true if you demaximize ("restore") and then remaximize the window?

actually i just assumed that was it, but i cannot replicate it. Demaximizing doesn't seem to do anything. Interestingly when you change the Windows resolution, you get these thick bars around the window in the same color as the 1 pixel line:
https://i.imgur.com/lhCmzjz.png

Comment 30

[Ray Kraesig [:rkraesig]]

Investigation suggests that this was a manifestation of bug 642851. I say "was" because that bug, and hence this one, are fixed in the latest Nightly.

Closing as duplicate. (Feel free to reopen if you can still repro.)

(In reply to mbattjes from comment #29)

actually i just assumed that was it, but i cannot replicate it. Demaximizing doesn't seem to do anything. Interestingly when you change the Windows resolution, you get these thick bars around the window in the same color as the 1 pixel line:
https://i.imgur.com/lhCmzjz.png

Despite the related effect, this is a different bug and should probably be filed as such.