Crash in TiledPanes::unset_fullscreen(), with no connected clients.

[vezult]

Basic information

$ zellij --version; stty size; uname -av
zellij 0.39.2
59 211
Linux cruella-devel 5.10.0-28-amd64 #1 SMP Debian 5.10.209-2 (2024-01-31) x86_64 GNU/Linux

Error:

Error occurred in server: panes

× Thread 'screen' panicked.
├─▶ Originating Thread(s)
│ 1. screen_thread: GoToTab
│
├─▶ At zellij-server/src/panes/tiled_panes/mod.rs:1574:50
╰─▶ called Option::unwrap() on a None value
help: If you are seeing this message, it means that something went wrong.

    -> To get additional information, check the log at: /tmp/zellij-1004/zellij-log/zellij.log
    -> To see a backtrace next time, reproduce the error with: RUST_BACKTRACE=1 zellij [...]
    -> To help us fix this, please open an issue: https://github.com/zellij-org/zellij/issues

zellij-error-2024-02-19.log

Further information

I have had various similar crashes. I am fairly certain that previous cases there was some relation to connected clients as well (src/panes/tiled_panes/mod.rs:1574:50). I do not have the tracebacks to prove it, however.

I was not actively interacting with zellij when the crash occurred. I returned to the terminal window where zellij was running, and found that it had crashed. I rarely encounter this crash when actively using zellij.

I use zellij on a remote machine, connected via openssh/mosh.

Re: src/panes/tiled_panes/mod.rs:1574:50

So, it seems that if *connected_clients.iter().next() can return None, then it might be reasonable to exit the function, doing nothing. If there are no clients, it would seem that there cannot be an active pane.

In a brief attempt, I wasn't able figure out how to write a test where Tab can modify panes after all clients are removed, but it seems as if there may be a hole there somewhere.