Quoting from Jeff King's commit message:
Commit e8cbe2118a (am: stop exporting GIT_COMMITTER_DATE, 2020-08-17)
rewrote the code for setting the committer date to use fmt_ident(),
rather than setting an environment variable and letting commit_tree()
handle it. But it introduced two bugs:
- we use the author email string instead of the committer email
- when parsing the committer ident, we used the wrong variable to
compute the length of the email, resulting in it always being a
zero-length string
The regression affected both am and rebase. Apply the upstream fixes.
References:
https://lore.kernel.org/git/20201023070747.GA2198273@coredump.intra.peff.net/
