SUMMARY When unmaximizing Firefox, the screen to the bottom and right of the window's new position flickers until I unfocus Firefox, and afterwards the corners still render oddly. STEPS TO REPRODUCE 1. Start KDE X11. 2. Open and maximize Firefox. 3. Unmaximize it by clicking the title bar button. (Alternatively press Super+arrow to snap it to the left or right of the screen, which triggers flickering. Then click to another window and back to Firefox, and press Super+the same arrow again, which will flicker for a moment.) OBSERVED RESULT The screen below and to the right of Firefox (x-right >= firefox.left, y-down >= firefox.top) begins to flicker between the shadow drawn over the correct underlying windows, and the shadow drawn over Firefox's old maximized contents. EXPECTED RESULT KWin with compositing on does not flicker. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.25.0 KDE Frameworks Version: 5.95.0 Qt Version: 5.15.4 Kernel Version: 5.18.3-zen1-1-zen (64-bit) Graphics Platform: X11 Processors: 12 × AMD Ryzen 5 5600X 6-Core Processor Memory: 15.5 GiB of RAM Graphics Processor: NVIDIA GeForce GT 730/PCIe/SSE2 Manufacturer: Gigabyte Technology Co., Ltd. Product Name: B550M DS3H ADDITIONAL INFORMATION This bug was discovered on system title-bar Firefox, but also occurs to an extent on custom title-bar CSD Firefox. I could not test on Wayland because I'm on an old GPU no longer receiving driver updates.
I have same problem when I drag my browser left or right: https://webmshare.com/5KWEL I have AMD GPU and X11. It also happens with Thunderbird
I get the same sort of behavior when I use Meta+L to "Quick Tile to Left" with either Firefox 101.0.1 or Chromium 103.0.5060.53 in KDE Neon 5.25. If I drag the title bar to the left to tile to the left, I do not see this behavior. See the attached gif. In it, I start with Firefox maximized, then press Meta+L to tile to the left to exhibit the flicker. Then I Meta+Up to maximize again, then I drag the window to the left to tile without flicker, then I maximize with the title bar Maximize button. Operating System: KDE neon 5.25 KDE Plasma Version: 5.25.0 KDE Frameworks Version: 5.95.0 Qt Version: 5.15.4 Kernel Version: 5.13.0-51-generic (64-bit) Graphics Platform: X11 Processors: 4 × Intel® Core™ i5 CPU M 520 @ 2.40GHz Memory: 7.6 GiB of RAM Graphics Processor: NVA8 Manufacturer: LENOVO Product Name: 43142MU System Version: ThinkPad T510 ``` System: Host: Marvin Kernel: 5.13.0-51-generic x86_64 bits: 64 compiler: N/A Console: tty 0 wm: kwin_x11 dm: SDDM Distro: KDE neon 20.04 5.25 base: Ubuntu 20.04 LTS Focal Machine: Type: Laptop System: LENOVO product: 43142MU v: ThinkPad T510 serial: R8322DB Chassis: type: 10 serial: R8322DB Mobo: LENOVO model: 43142MU serial: 1ZHP102123Z BIOS: LENOVO v: 6MET91WW (1.51 ) date: 06/05/2012 CPU: Topology: Dual Core model: Intel Core i5 M 520 bits: 64 type: MT MCP arch: Nehalem rev: 2 L1 cache: 32 KiB L2 cache: 3072 KiB L3 cache: 3072 KiB flags: lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx bogomips: 19151 Speed: 1333 MHz min/max: 1199/2400 MHz Core speeds (MHz): 1: 1455 2: 1463 3: 1415 4: 1463 Graphics: Device-1: NVIDIA GT218M [NVS 3100M] vendor: Lenovo driver: nouveau v: kernel bus ID: 01:00.0 chip ID: 10de:0a6c Display: server: X.Org 1.20.13 driver: modesetting unloaded: fbdev,vesa compositor: kwin_x11 resolution: 1366x768~60Hz OpenGL: renderer: NVA8 v: 3.3 Mesa 21.2.6 direct render: Yes ``` Please let me know if I can provide more info. Thanks!
Created attachment 150094 [details] Firefox flickering when Quick-Tiling to Left with Meta+L Firefox flickering when Quick-Tiling to Left with Meta+L, then no flicker when tiling by dragging title bar to left.
It should be fixed in 5.25.1 *** This bug has been marked as a duplicate of bug 455617 ***