Bug 430390 - Panel has black edge when compositor is disabled
Summary: Panel has black edge when compositor is disabled
Alias: None
Product: plasmashell
Classification: Plasma
Component: Panel (show other bugs)
Version: 5.20.4
Platform: Arch Linux Linux
: VHI normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
Keywords: regression
: 430367 430482 431339 (view as bug list)
Depends on:
Reported: 2020-12-14 18:07 UTC by Frank Steinmetzger
Modified: 2021-01-09 09:05 UTC (History)
9 users (show)

See Also:
Latest Commit:
Version Fixed In: 5.78
Sentry Crash Report:

Screenshot of the desktop and panel. Notice the clipped clock at the bottom (43.00 KB, image/jpeg)
2020-12-14 18:07 UTC, Frank Steinmetzger

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Description Frank Steinmetzger 2020-12-14 18:07:32 UTC
Created attachment 134078 [details]
Screenshot of the desktop and panel. Notice the clipped clock at the bottom

I am running a virtual Linux on my work machine. For performance reasons, I disabled 3D stuff in it. Last weekend I updated Plasma form 5.20.3 to 5.20.4. Since then, the panel has a black bar at its edge toward the desktop area right after boot.

The bar is also visible when the panel is placed at the bottom of the screen. Once I enable the compositor, the black bar disappears. After I disabled the compositor with Alt+Shift+F12, the bar comes back.

Now that I think of it, I also noticed a similar glitch on my main PC which runs Linux natively on a Radeon card. there I saw it happen when I started a 3D game, which probably disabled the compositor temporarily.

Plasma 5.20.4
Frameworks 5.77.0
Qt 5.15.2
Comment 1 Doogie 2020-12-14 22:49:59 UTC
I can confirm this issue.  Appeared with the update to Plasma 5.20.4.

I am using an Nvidia card and have a native install (not virtual)

I am using Arch as well.  This happens with the panel at top as well and persists into the second screen with the same effect.

Plasma 5.20.4
Frameworks 5.77.0
Qt 5.15.2
Comment 2 Doogie 2020-12-16 03:00:48 UTC
Not sure if it is related or if this needs to be another bug report, but some programs are no longer properly suspending composting.

I have several games in my steam library that do not suspend compositing like they should and did prior.  These are Linux native games. 

None of the games that run via proton 5.13-4 will suspend compositing when all did before.  This part may be related to a proton bug as previous versions suspend compositing properly.

Until this point, all native games did suspend compositing properly when the option to allow programs to suspend compositing was selected, so I think at least the native game issue might be related.  Maybe something was changed in the compositing settings that caused both these issues?

As I said above this might need to be a separate bug report but as it seems to appeared at the same time as the "ugly panel issue" I thought I would mention it here in case it will help you to track down the issue
Comment 3 Nate Graham 2020-12-16 22:07:46 UTC
*** Bug 430367 has been marked as a duplicate of this bug. ***
Comment 4 Doogie 2020-12-16 22:27:11 UTC
I did some further testing today and it looks like it was just an update that was preventing compositing from suspending on all my native games, or a failure to load something properly on boot temporarily as the issue went away during reboot so please disregard my comment about that as a possible direction to investigate.  

All but a few of my native games suspend compositing properly after a reboot.  The few that remain are just not coded properly to report a true full screen application it would appear.  

I apologize for a possible false trail, I should have rebooted and checked again before posting my comment....
Comment 5 David Edmundson 2020-12-17 12:13:50 UTC

Caused by c709076d9c52cbd177de18b3f199917f32d416dc in plasma-frameworks
Comment 6 David Edmundson 2020-12-17 12:23:44 UTC
Easier way to test:

diff --git a/tests/testborders.qml b/tests/testborders.qml
index 62c9c6ed7..10eea79cf 100644
--- a/tests/testborders.qml
+++ b/tests/testborders.qml
@@ -20,7 +20,7 @@ Item
     PlasmaCore.FrameSvgItem {
         id: theItem
-        imagePath: "widgets/background"
+        imagePath: "opaque/widgets/panel-background"
         anchors {
             fill: parent
             margins: 10
Comment 7 Bug Janitor Service 2020-12-17 12:42:15 UTC
A possibly relevant merge request was started @ https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/171
Comment 8 David Edmundson 2020-12-17 13:22:08 UTC
Git commit b1364fa601866792ecf69cf61b8ab48732150857 by David Edmundson.
Committed on 17/12/2020 at 12:41.
Pushed by mart into branch 'master'.

Fix broken background

In commit c709076d9c52cbd177de18b3f199917f32d416dc the SVG got somehow
broken leading to black rectangles in all cases where it was used.

This commit reverts to the last working version, then reapplies the
"thick margin" from the change.

A test is supplied to show all our frameSVGs to hopefully make this
easier to spot if it happens again.

M  +420  -80   src/desktoptheme/breeze/opaque/widgets/panel-background.svg
A  +41   -0    tests/frames.qml     [License: LGPL(v2.0+)]

Comment 9 Nate Graham 2020-12-17 21:16:18 UTC
*** Bug 430482 has been marked as a duplicate of this bug. ***
Comment 10 Roberto Orden 2021-01-05 18:38:08 UTC
As a curious thing, if I set a new user in kde and I login with it, the error is not visible.
Comment 11 Doogie 2021-01-06 01:04:12 UTC
(In reply to Roberto Orden from comment #10)
> As a curious thing, if I set a new user in kde and I login with it, the
> error is not visible.

That is because if you are using an older version of Plasma you don't have the bug, kubuntu for example.  If you using the newer versions like in Plasma Neon, Arch, etc the bug has been fixed
Comment 12 Rik Mills 2021-01-09 09:05:34 UTC
*** Bug 431339 has been marked as a duplicate of this bug. ***