Re: [PATCH 06/13] format-patch: use default email for generating message ids

Jeff King [off-list ref] writes:

We try to generate a sane message id for cover letters and
threading by appending some changing bits to the front of
the user's email address. The current code parses the email
out of the results of git_committer_info, but we can do this
much more easily by just calling ident_default_email
ourselves.

Signed-off-by: Jeff King <redacted>
---
Technically this is a regression if you really wanted:

  GIT_COMMITTER_EMAIL=some.addr@example.com \
  git format-patch --thread=deep

to make your environment variable part of the message-ids. I don't think
it matters, but I can adjust it if we care.

Is it because you no longer explicitly ask for "committer" and get generic
"who am I" bit from the ident infrastructure?

I wouldn't be surprised if some automated "commit email notification
reacting to push" bot in post-receive hook is using the environment
variable to affect the message ID.  I would doubt that would break the
message as long as the message ID generated from this codepath stays
valid, though, so I wouldn't worry about complaints along the lines of
"you started using names different from what you used to use".  As long as
we don't die due to "Hey bot, you do not seem to have a valid e-mail
address!", I don't think we need to worry about it.