What Operating System(s) are you seeing this problem on?

macOS

Which Wayland compositor or X11 Window manager(s) are you using?

AeroSpace

WezTerm version

20240203-110809-5046fc22 + main

Did you try the latest nightly build to see if the issue is better (or worse!) than your current version?

Yes, and I updated the version box above to show the version of the nightly that I tried

Describe the bug

Example:

+-----+
|  A  |
+-----+
|  B  |
+-----+

Command: split-pane --pane-id $B_PANE_ID --move-pane-id $A_PANE_ID

In Domain::split_pane (in mux/src/domain.rs), with a SplitSource::MovePane, the splitting pane (pane B) is first translated into a pane index (1) for its tab. Then, pane A is removed from its tab. However, this changes pane B's index (now 0). Subsequently, when we call tab.split_and_insert(b_old_index, ..., the old index 1 is incorrect; in this example it is in fact invalid as there is only a single pane, and pane A never gets reattached to the tab.

To Reproduce

In a new tab, split the pane vertically. In the bottom pane, run:
wezterm cli split-pane --move-pane-id $(wezterm cli get-pane-direction up)

Configuration

no config

Expected Behavior

Top pane should be moved into the right side of a horizontal split of the previously bottom pane.

Logs

No response

Anything else?

No response