Commit ba67d20b7 (Refresh TTY timestamps after nextd/prevd, 2024-10-13)
wasn't quite right because it also needs to fix it for arbitrary commands.
While at it, do this only when needed:
1. It seems to be only relevant for multiline prompts.
Note that we can wait until after evaluation to check if the prompt is
multiline, because repaint events go through the queue, see 5ba21cd29
(Send repaint requests through the input queue again, 2024-04-19).
2. When the binding doesn't execute any external command, we probably don't
need to fix up whatever the user printed. If they actually wanted to show
output and print another prompt, they should currently use "__fish_echo",
to properly support multiline prompts. Bindings should produce no other
output. What distinguishes external programs is that they can trigger this
issue even if they don't produce any output that remains visible in fish,
namely by using the terminal's alternate screen.
Would be nice if we could get rid of __fish_echo; I'm not yet sure how.
Fixes#10800
2dbaf10c36