Upgrade StorageBug Report: Right border ghosting/flickering when dragging window (Zotero 9, Linux, GNOME)
https://s3.amazonaws.com/zotero.org/images/forums/u15731631/lcqh25jfn6fgqfa6dua8.png
Bug Report: Right border ghosting/flickering when dragging window (Zotero 9, Linux, GNOME)
Environment
- Zotero version: 9.0.x (latest, tarball and Flatpak both tested)
- OS: Linux (GNOME desktop)
- Display server: Both X11 and Wayland tested, both affected
- GPU: AMD (Mesa driver)
- Scaling: 100% (no fractional scaling)
- Zotero 7: NOT affected (confirmed regression)
Steps to reproduce
1. Install Zotero 9 (tarball or Flatpak)
2. Launch Zotero
3. Open any PDF document in the built-in reader
4. Drag the Zotero window by its title bar
5. Observe: the right edge/border of the window flickers/ghosts with artifacts during the drag
6. Close all documents: flickering stops
7. Maximize/fullscreen the window: flickering stops (windowed only)
What has been ruled out
- NOT display server specific: occurs on both X11 and Wayland (GNOME on Xorg and GNOME on Wayland)
- NOT GPU acceleration: occurs with layers.acceleration.disabled=true, gfx.webrender.force-disabled=true, and software rendering
- NOT Flatpak-specific: reproduces with the official tarball from zotero.org
- NOT scaling-related: occurs at 100% scaling
- NOT a plugin issue: occurs with clean profile, no plugins
Terminal output (no crash, just visual artifact)
Missing chrome or resource URL: chrome://zotero/skin/16/white/loading.svg
(Otherwise clean output - no GFX errors reported)
Notes
- The artifact appears specifically on the right border of the window
- It only occurs when at least one document (PDF) tab is open in the reader pane
- Zotero 7 on the same hardware/OS has no such issue → regression in Zotero 9
- Suspected cause: Firefox/Gecko rendering surface size mismatch with Mutter compositor window bounds during DnD, possibly related to WebRender/SWGL compositor integration