The .mailmap is documented to be read only from the root level of a working tree, but a stray file in a bare repository also was read by accident, which has been corrected with Git 2.31 (Q1 2021).
See commit a38cb98 (10 Feb 2021) by Jeff King (peff).
(Merged by Junio C Hamano -- gitster -- in commit 9bdccbc, 17 Feb 2021)
mailmap: only look for .mailmap in work tree
Signed-off-by: Jeff King
When trying to find a .mailmap file, we will always look for it in the current directory.
This makes sense in a repository with a working tree, since we'd always go to the toplevel directory at startup.
But for a bare repository, it can be confusing.
With an option like --git-dir (or $GIT_DIR in the environment), we don't chdir at all, and we'd read .mailmap from whatever directory you happened to be in before starting Git.
(Note that --git-dir without specifying a working tree historically means the current directory is the root of the working tree, but most bare repositories will have core.bare set these days, meaning they will realize there is no working tree at all).
The documentation for gitmailmap(5) says:
If the file `.mailmap` exists at the toplevel of the repository[...]
which likewise reinforces the notion that we are looking in the working tree.
This patch prevents us from looking for such a file when we're in a bare repository.
This does break something that used to work:
cd bare.git
git cat-file blob HEAD:.mailmap >.mailmap
git shortlog
But that was never advertised in the documentation.
And these days we have mailmap.blob (which defaults to HEAD:.mailmap) to do the same thing in a much cleaner way.
However, there's one more interesting case: we might not have a repository at all! The git-shortlog(man) command can be run with git-log output fed on its stdin, and it will apply the mailmap.
In that case, it probably does make sense to read .mailmap from the current directory.
This patch will continue to do so.
That leads to one even weirder case: if you run git-shortlog to process stdin, the input could be from a different repository entirely.
Should we respect the in-tree .mailmap then? Probably yes.
Whatever the source of the input, if shortlog is running in a repository, the documentation claims that we'd read the .mailmap from its top-level (and of course it's reasonably likely that it is from the same repo, and the user just preferred to run git-log(man) and git-shortlog separately for whatever reason).
The included test covers these cases, and we now document the "no repo" case explicitly.
We also add a test that confirms we find a top-level ".mailmap" even when we start in a subdirectory of the working tree.
This worked both before and after this commit, but we never tested it explicitly (it works because we always chdir to the top-level of the working tree if there is one).
git shortlog now includes in its man page:
Note that if git shortlog is run outside of a repository (to process
log contents on standard input), it will look for a .mailmap file in
the current directory.
