crash on switch to moved-out-of workspace

[diagonalisability]

• Sway Version: 1.5-169b90f9

• Debug Log: https://gist.github.com/diagonalisability/421383a454e47e6fab706b241990e273

• Configuration File: https://gist.github.com/diagonalisability/ae85eb5efe692d1571aab6d69c95bc50

• Stack Trace: https://gist.github.com/diagonalisability/893814a3c7d373a4b0aad8832d099ec1

• Description:

  • Create a tiled window.
  • Push LMB down on the window.
  • Switch to an empty workspace.
  • Move the mouse.
  • Switch back to the original workspace, without moving the mouse.
  • Release LMB.
  • Sway crashes.

This is a pretty niche bug, so it's not exactly workflow-breaking.

My guess: sway is trying to arrange the window in a workspace that no longer exists, so this is a use-after-free. The fix is probably to make sure that workspaces don't get destroyed while the tiling window move indicator is inside that workspace.

[diagonalisability]

I tried fixing this bug here: https://github.com/swaywm/sway/compare/master...diagonalisability:fix-issue-6000 This fix causes some very strange behaviour though, because after a tiling window move, sway focuses the moved window, which is now in a different workspace. Creating a second window, for example, switches the current workspace to the one where the first window was moved to, since sway creates a new window in the same workspace as the focused window, and then focuses the new window. Perhaps moving a tiling window shouldn't focus it? I'm not sure what the correct behaviour is.

[emersion]

Maybe ASan will tell you more about the use-after-free. See the wiki for instructions to build with ASan

Can't the seatop listen on the container/node destroy event?