With one exception, the print_email_subject flag is set if and only if
the commit format is email based:
- in make_cover_letter() we set it along with CMIT_FMT_EMAIL
explicitly
- in show_log(), we set it if cmit_fmt_is_mail() is true. That covers
format-patch as well as "git log --format=email" (or mboxrd).
The one exception is "rev-list --format=email", which somewhat
nonsensically prints the author and date as email headers, but no
subject, like:
$ git rev-list --format=email HEAD
commit 64fc4c2cdd4db2645eaabb47aa4bac820b03cdba
From: Jeff King <peff@peff.net>
Date: Tue, 19 Mar 2024 19:39:26 -0400
this is the subject
this is the body
It's doubtful that this is a useful format at all (the "commit" lines
replace the "From" lines that would make it work as an actual mbox).
But I think that printing the subject as a header (like this patch does)
is the least surprising thing to do.
So let's drop this field, making the code a little simpler and easier to
reason about. Note that we do need to set the "rev" field of the
pretty_print_context in rev-list, since that is used to check for
subject_prefix, etc. It's not possible to set those fields via rev-list,
so we'll always just print "Subject: ". But unless we pass in our
rev_info, fmt_output_email_subject() would segfault trying to figure it
out.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
d5a90d6319