MacOS, vim, git and exit…

On git commit, git invokes an editor (by default: vi) and allows you to edit a commit message. If the editor exits with status code 0, the commit message is accepted and used. If the editor exists with status code >0, this is an error and the commit is aborted. The commit message is lost.

On MacOS, calling /usr/bin/vi, the editor shipped with the OS, starts vim 9.0.1424 in vi mode. In this mode, if you enter an illegal editor command such as :W, the editor will exit with status 1. This will happen even when you enter a legal editor command afterwards. So

:W keks
:w keks
:q

will

kk:~ kris$ vi
kk:~ kris$ echo $?
1

This does not happen if the same editor is called as vim. This does not happen on Ubuntu 22.04, which as vim 8.2.4919 installed – it will exit 0 as vi or vim. This suggests that this behavior of vim 9, when called as “vi” in compatibility mode, is an “improvement” that has been added on purpose. I wonder if that is really the case.

In vim, the command :<status>cq to force an exit status.

:1cq
kk:~ kris $ echo $?
1

You can also :0cq to force a zero. This also works in compatibility mode. You can, of course, also

$ git config --global core.editor "vim"