Why “there was a problem with vi” when saving a git commit message with :wq after accidental :Wq?

Question

When I have typed a commit message with vim and, in haste, typed :Wq instead of :wq I get an error:

E492: Not an editor command: Wq

from which I can (falsly?) recover, meaning the editor seems to function as normal and I can try to properly write and quit the buffer with :wq. However, git-commit fails with:

error: There was a problem with the editor 'vi'.
Please supply the message using either -m or -F option.

What has happened? Is this a misinterpretation in git's part? Can I somehow recover and actually save the commit message after accidental :Wq? Besides copy and pasting what I've written…

My vi is actually symlinked to vim and version is 8.0

Answer 1

Git actually checks the exit code of whatever editor you have configured and outputs that error message if it's non-zero.

I couldn't replicate the problem with your commands but you may have better luck. Simply run vim normally (i.e., not via git), enter the :Wq and :wq commands (and whatever else you did in between those two), then check the exit code with (for Linux) echo $?.

If that's not zero, you at least have a repeatable test you can use for further investigation, at which point you can start experimenting with vim options (as shown in this question for example).

You could also opt for a different editor which doesn't return non-zero. There's probably no reason to need the massive power of Vim for composing what are (hopefully) one-liner commit messages.

In fact, I don't use any editor, instead relying on the command-line bevaviour only. For one-liners:

pax$ git commit -m "Fixed my co-worker's atrocious code :-)"

or, more more complex messages:

pax$ git commit -F - 
(reading log message from standard input)
Fixed my co-worker's atrocious code, specifically:
- no comments;
- unreadable formatting;
- bad variable names.
<CTRL-D>

As to how you easily get at the comment you just tried to use, that should be stored in .git/COMMIT_EDITMSG so you can just use:

git commit -F .git/COMMIT_EDITMSG

(or -eF if you want to check or further edit the message).