Public bug reported: [Impact]
Snapping a window to a screen edge silently fails whenever the window is already exactly the size of the tile it is being snapped to. The window flashes into position and springs straight back, ending up where it started but flush with the top of the work area. This is easy to hit without trying, because applications remember their window size across restarts. Tiling a window sets it to the tile size, so after a restart the window opens at exactly the size that breaks tiling, and stays that way until something resizes it. Firefox writes the tiled geometry straight into xulstore.json; GNOME applications do the same via GSettings. Affects all four half-tiles (left, right, top, bottom). Quarter tiles and maximize are unaffected. The regression has been present for the whole life of 26.04. All commits and pull requests below are in ubuntu/Tiling-Assistant, the repository that gnome-shell-ubuntu-extensions tracks as a meson subproject: https://github.com/ubuntu/Tiling-Assistant It was introduced by: 204c662256f7711ef7f4710b139b3ea8237cd913 "tilingWindowManager: Semi-maximize windows when possible" committed 2026-04-15 https://github.com/ubuntu/Tiling-Assistant/commit/204c662256f7711ef7f4710b139b3ea8237cd913 which is included in the 50.26.04.7ubuntu package that 26.04 released with. [Test Case] 1. On a 26.04 desktop (Wayland), open Firefox. 2. Press Super+Right. The window tiles correctly. 3. Quit Firefox and reopen it. It restores at the right-half size. 4. Press Super+Right again. Without the fix: the window jumps to the right edge and springs back to roughly where it was, now flush with the top of the work area. With the fix: the window tiles to the right half and stays there. [Where problems could occur] The fix reorders two existing calls in TilingWindowManager.tile(): the semi-maximize flags are applied after the window has been moved and resized rather than before. Any regression would therefore show up in tiling itself -- windows landing on the wrong rect, or losing the semi-maximized styling that commit 204c662256f7711ef7f4710b139b3ea8237cd913 was added to provide. One thing worth knowing before uploading: the same upstream change introduces a second, separate bug. Restoring a tiled window with Super+Down no longer returns it to its pre-tile position, under the same narrow condition (pre-tile size equal to the tile size). This was reproduced on extension v55 built from ubuntu/Tiling-Assistant main, in a clean VM, with the packaged extension disabled so only the one copy was active. It would be preferable to pick up a tiling-assistant revision that also carries a fix for that, so 26.04 users do not trade one problem for the other. [Other Info] Fixed in ubuntu/Tiling-Assistant by: 2d64aa8dfb546167d46d62f00bb1cf74b7e27f49 "tilingWindowManager: Semi-maximize after moving and resizing the window" committed 2026-09-20 https://github.com/ubuntu/Tiling-Assistant/commit/2d64aa8dfb546167d46d62f00bb1cf74b7e27f49 part of: PR #471 "Tiling rects fixes", merged 2026-09-20 https://github.com/ubuntu/Tiling-Assistant/pull/471 released as extension version 55. Already shipped in 26.10 as 51.26.10.3ubuntu, whose changelog reads "subprojects: Update tiling assistant to latest release ... Apply the semi-maximize state after moving the window so it lands on the intended tile". No JS errors or warnings appear in journalctl during the failure. The effect is a race resolved within about 50ms: the window visibly reaches the correct tile before being moved back, so it needs either sampling or a careful eye to observe. [System Info] Ubuntu 26.04.1 LTS (resolute), Wayland gnome-shell 50.1, mutter 18 gnome-shell-ubuntu-extensions 50.26.04.7ubuntu Bundled [email protected] extension version: 54 Also reproduces on 50.26.04.8ubuntu from resolute-updates, which still bundles extension v54. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: gnome-shell-ubuntu-extensions 50.26.04.7ubuntu ProcVersionSignature: Ubuntu 7.0.0-34.34-generic 7.0.14 Uname: Linux 7.0.0-34-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia ApportVersion: 2.34.1-0ubuntu0.1 Architecture: amd64 CasperMD5CheckResult: pass CurrentDesktop: ubuntu:GNOME Date: Thu Oct 1 17:02:29 2026 InstallationDate: Installed on 2026-09-24 (7 days ago) InstallationMedia: Ubuntu 26.04.1 LTS "Resolute Raccoon" - Release amd64 (20260826) PackageArchitecture: all ProcEnviron: LANG=en_US.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> SourcePackage: gnome-shell-ubuntu-extensions UpgradeStatus: No upgrade log present (probably fresh install) ** Affects: gnome-shell-ubuntu-extensions (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug resolute wayland-session -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2169235 Title: Tiling Assistant: snapping fails when the window is already the size of the target tile To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-shell-ubuntu-extensions/+bug/2169235/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
