Close #23027
`git commit` message option _only_ supports 4 formats (well, only ....):
* `"commit", "-m", msg`
* `"commit", "-m{msg}"` (no space)
* `"commit", "--message", msg`
* `"commit", "--message={msg}"`
The long format with `=` is the best choice, and it's documented in `man
git-commit`:
`-m <msg>, --message=<msg> ...`
ps: I would suggest always use long format option for git command, as
much as possible.
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>