sway locked up in infinite loop apparently related to selecting text under xwayland using a tablet pen

[SimonWoolf]

• Sway Version: 1.9

• Debug Log:
  Here's the relevant section of the sway log, when the problem started.

81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:374] XCB_SELECTION_REQUEST (time=0 owner=2097153, requestor=228589568 selection=275, target=253, property=429)
81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:295] Sending Wayland selection 253 to Xwayland window with MIME type text/plain;charset=utf-8, target 253, transfer 0x601d4f6a7300
81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:215] Starting transfer 0x601d4f6a7300
81:11:35.508 [DEBUG] [sway/desktop/xwayland.c:790] New xwayland surface title='(null)' class='(null)'
81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:374] XCB_SELECTION_REQUEST (time=0 owner=2097153, requestor=2097202 selection=275, target=253, property=276)
81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:295] Sending Wayland selection 253 to Xwayland window with MIME type text/plain;charset=utf-8, target 253, transfer 0x601d4fc70690
81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f6a7300 still running
81:11:35.508 [DEBUG] [wlr] [xwayland/selection/outgoing.c:215] Starting transfer 0x601d4fc70690
81:11:35.509 [DEBUG] [sway/desktop/xwayland.c:790] New xwayland surface title='(null)' class='(null)'
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:374] XCB_SELECTION_REQUEST (time=0 owner=2097153, requestor=2097203 selection=275, target=253, property=276)
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:295] Sending Wayland selection 253 to Xwayland window with MIME type text/plain;charset=utf-8, target 253, transfer 0x601d4fb91ce0
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fc70690 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f6a7300 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:215] Starting transfer 0x601d4fb91ce0
81:11:35.509 [DEBUG] [sway/desktop/xwayland.c:790] New xwayland surface title='(null)' class='(null)'
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:374] XCB_SELECTION_REQUEST (time=0 owner=2097153, requestor=2097204 selection=275, target=253, property=276)
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:295] Sending Wayland selection 253 to Xwayland window with MIME type text/plain;charset=utf-8, target 253, transfer 0x601d4f66f710
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fb91ce0 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fc70690 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f6a7300 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:215] Starting transfer 0x601d4f66f710
81:11:35.509 [DEBUG] [sway/desktop/xwayland.c:790] New xwayland surface title='(null)' class='(null)'
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:374] XCB_SELECTION_REQUEST (time=0 owner=2097153, requestor=2097205 selection=275, target=253, property=276)
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:295] Sending Wayland selection 253 to Xwayland window with MIME type text/plain;charset=utf-8, target 253, transfer 0x601d4f634ff0
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f66f710 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fb91ce0 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fc70690 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f6a7300 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:215] Starting transfer 0x601d4f634ff0
81:11:35.509 [DEBUG] [sway/desktop/xwayland.c:790] New xwayland surface title='(null)' class='(null)'
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:374] XCB_SELECTION_REQUEST (time=0 owner=2097153, requestor=2097206 selection=275, target=253, property=276)
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:295] Sending Wayland selection 253 to Xwayland window with MIME type text/plain;charset=utf-8, target 253, transfer 0x601d4f91f7d0
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f634ff0 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f66f710 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fb91ce0 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4fc70690 still running
81:11:35.509 [DEBUG] [wlr] [xwayland/selection/outgoing.c:311] Transfer 0x601d4f6a7300 still running
...

You can see the pattern. It continues indefinitely, with one more "Transfer 0x... still running" line each time.

More complete log: https://gist.github.com/SimonWoolf/b2bbf5f3feb7ef5e1e11b51216e7b7c2 . (This is not quite the full log, because the full log is 14 GiB. I included the first few thousand lines, and a couple thousand before the bug happened)

• Configuration File: https://gist.github.com/SimonWoolf/c30f9671cdd00bd668e51cb8eb0cdabb

• Stack Trace: n/a

• Description:

I was interacting with the alacritty terminal using the wacom tablet pen. I run alacritty under xwayland because when running under wayland natively, text selection and middle-click paste don't work properly when using the tablet pen. (They work fine using a mouse).

I can't be certain on precisely what it was I was doing. Probably selecting something.

Sway completely locked up, using 100% cpu. All input devices on that computer become unresponsive, but I was able to ssh in from another computer to kill sway.

This has only ever happened once (just now). I can't reproduce on-demand. Hopefully even without full repro steps the debug log is still enough for this to be a useful bug report