Created attachment 120213 [details] screenshot of issue In a wayland session, the task switcher has a black border around it. I tried large icons, compact, and breeze, and each exhibited this bug. This does not happen in an X11 session.
What if you try some different desktop theme? Also, can you post output of `qdbus org.kde.KWin /KWin supportInformation`?
The bug is there with other themes. I tried Air, Oxygen, and Breath (manjaro). Sometimes the black border is even larger, depending on the theme. I suppose it's related to the shadow? While switching themes, at one point a black border appeared at the top of the panel (which I have placed at the bottom). I had to switch themes a couple of times to get rid of it. Output of qdbus org.kde.KWin /KWin supportInformation: KWin Support Information: The following information should be used when requesting support on e.g. https://forum.kde.org. It provides information about the currently running instance, which options are used, what OpenGL driver and which effects are running. Please post the information provided underneath this introductory text to a paste bin service like http://paste.kde.org instead of pasting into support threads. ========================== Version ======= KWin version: 5.15.5 Qt Version: 5.12.3 Qt compile version: 5.12.3 XCB compile version: 1.13.1 Operation Mode: Xwayland Build Options ============= KWIN_BUILD_DECORATIONS: yes KWIN_BUILD_TABBOX: yes KWIN_BUILD_ACTIVITIES: yes HAVE_DRM: yes HAVE_GBM: yes HAVE_X11_XCB: yes HAVE_EPOXY_GLX: yes HAVE_WAYLAND_EGL: yes X11 === Vendor: The X.Org Foundation Vendor Release: 12004000 Protocol Version/Revision: 11/0 SHAPE: yes; Version: 0x11 RANDR: yes; Version: 0x14 DAMAGE: yes; Version: 0x11 Composite: yes; Version: 0x4 RENDER: yes; Version: 0xb XFIXES: yes; Version: 0x50 SYNC: yes; Version: 0x31 GLX: yes; Version: 0x0 Decoration ========== Plugin: org.kde.breeze Theme: Blur: 0 onAllDesktopsAvailable: true alphaChannelSupported: true closeOnDoubleClickOnMenu: false decorationButtonsLeft: decorationButtonsRight: 5 borderSize: 0 gridUnit: 10 font: Noto Sans,10,-1,5,50,0,0,0,0,0,Regular smallSpacing: 2 largeSpacing: 10 Platform ========== Name: DRM Active: true Atomic Mode Setting: true Options ======= focusPolicy: 0 nextFocusPrefersMouse: false clickRaise: true autoRaise: false autoRaiseInterval: 0 delayFocusInterval: 0 shadeHover: false shadeHoverInterval: 250 separateScreenFocus: false placement: 4 focusPolicyIsReasonable: true borderSnapZone: 10 windowSnapZone: 10 centerSnapZone: 0 snapOnlyWhenOverlapping: false rollOverDesktops: true focusStealingPreventionLevel: 1 legacyFullscreenSupport: false operationTitlebarDblClick: 5015 operationMaxButtonLeftClick: 5000 operationMaxButtonMiddleClick: 5015 operationMaxButtonRightClick: 5014 commandActiveTitlebar1: 0 commandActiveTitlebar2: 30 commandActiveTitlebar3: 2 commandInactiveTitlebar1: 4 commandInactiveTitlebar2: 30 commandInactiveTitlebar3: 2 commandWindow1: 7 commandWindow2: 8 commandWindow3: 8 commandWindowWheel: 31 commandAll1: 10 commandAll2: 3 commandAll3: 14 keyCmdAllModKey: 16777250 showGeometryTip: false condensedTitle: false electricBorderMaximize: true electricBorderTiling: true electricBorderCornerRatio: 0.25 borderlessMaximizedWindows: false killPingTimeout: 5000 hideUtilityWindowsForInactive: true inactiveTabsSkipTaskbar: false autogroupSimilarWindows: false autogroupInForeground: true compositingMode: 1 useCompositing: true compositingInitialized: true hiddenPreviews: 1 glSmoothScale: 2 xrenderSmoothScale: false maxFpsInterval: 16666666 refreshRate: 0 vBlankTime: 6000000 glStrictBinding: false glStrictBindingFollowsDriver: true glCoreProfile: true glPreferBufferSwap: 101 glPlatformInterface: 2 windowsBlockCompositing: true Screen Edges ============ desktopSwitching: false desktopSwitchingMovingClients: false cursorPushBackDistance: 1x1 timeThreshold: 150 reActivateThreshold: 350 actionTopLeft: 0 actionTop: 0 actionTopRight: 0 actionRight: 0 actionBottomRight: 0 actionBottom: 0 actionBottomLeft: 0 actionLeft: 0 Screens ======= Multi-Head: no Active screen follows mouse: no Number of Screens: 1 Screen 0: --------- Name: LEN HDMI-A-1-P24h-10/16843009 Geometry: 0,0,2560x1440 Scale: 1 Refresh Rate: 59.951 Compositing =========== Compositing is active Compositing Type: OpenGL OpenGL vendor string: Intel Open Source Technology Center OpenGL renderer string: Mesa DRI Intel(R) HD Graphics 620 (Kaby Lake GT2) OpenGL version string: 4.5 (Core Profile) Mesa 19.0.4 OpenGL platform interface: EGL OpenGL shading language version string: 4.50 Driver: Intel GPU class: Unknown OpenGL version: 4.5 GLSL version: 4.50 Mesa version: 19.0.4 Linux kernel version: 5.1.1 Direct rendering: Requires strict binding: no GLSL shaders: yes Texture NPOT support: yes Virtual Machine: no OpenGL 2 Shaders are used Painting blocks for vertical retrace: no Loaded Effects: --------------- kwin4_effect_squash kwin4_effect_fadingpopups kwin4_effect_morphingpopups kwin4_effect_login kwin4_effect_maximize kwin4_effect_fade kwin4_effect_dialogparent kwin4_effect_frozenapp kwin4_effect_windowaperture kwin4_effect_logout slidingpopups slide screenshot desktopgrid colorpicker presentwindows highlightwindow blur contrast startupfeedback screenedge kscreen Currently Active Effects: ------------------------- blur contrast Effect Settings: ---------------- kwin4_effect_squash: isActiveFullScreenEffect: false kwin4_effect_fadingpopups: isActiveFullScreenEffect: false kwin4_effect_morphingpopups: isActiveFullScreenEffect: false kwin4_effect_login: isActiveFullScreenEffect: false kwin4_effect_maximize: isActiveFullScreenEffect: false kwin4_effect_fade: isActiveFullScreenEffect: false kwin4_effect_dialogparent: isActiveFullScreenEffect: false kwin4_effect_frozenapp: isActiveFullScreenEffect: false kwin4_effect_windowaperture: isActiveFullScreenEffect: false kwin4_effect_logout: isActiveFullScreenEffect: false slidingpopups: slideInDuration: 150 slideOutDuration: 250 slide: duration: 500 horizontalGap: 45 verticalGap: 20 slideDocks: false slideBackground: false screenshot: desktopgrid: zoomDuration: 300 border: 10 desktopNameAlignment: 0 layoutMode: 0 customLayoutRows: 2 usePresentWindows: true colorpicker: presentwindows: layoutMode: 0 showCaptions: true showIcons: true doNotCloseWindows: false ignoreMinimized: false accuracy: 20 fillGaps: true fadeDuration: 150 showPanel: false leftButtonWindow: 1 rightButtonWindow: 2 middleButtonWindow: 0 leftButtonDesktop: 2 middleButtonDesktop: 0 rightButtonDesktop: 0 highlightwindow: blur: contrast: startupfeedback: type: 1 screenedge: kscreen:
Yes, it appears like this is related to shadows.
Created attachment 120216 [details] awesome screenshot I'm aware of similar issue on X11, though I haven't figured out why it happens. Apparently, that issue occurs only with some certain desktop themes, like Breeze Dark.
Don't the breeze and breeze dark plasma themes draw shadows in exactly the same way? Anyway, your help with fixing the issue is greatly appreciated!
(In reply to Michael D from comment #5) > Don't the breeze and breeze dark plasma themes draw shadows in exactly the > same way? Well, they have to...
Heh, I was facing a cache issue... Can you reproduce the bug after purging plasma cache? rm ~/.cache/plasma-svgelements* rm ~/.cache/plasma_theme*
You're right, seems to have been a cache issue. The problem is gone once I remove those files.
Requested info was already provided.
it was a problem with the cache. though please file a bug report against FrameSVG (it resides in plasma-framework, iirc)