git send-email --notmuch expr

Notmuch is a new mail system with fast indexing and tagging, see
notmuchmail.org.  It has a command-line tool to build replies to emails,
and I wrote a patch to format-patch that enables

  git format-patch --notmuch EXPR

where EXPR is any notmuch query, but usually id:<Message-ID> to match a
specific message.  This will set up several headers, notably
In-Reply-To, References, To, Cc, Bcc.  This works great, and the the
patch follows this message.


But I really want

  git send-email --notmuch EXPR

This sort-of works, but the interactive part prompts for the various
headers (even though format-patch supplies them), and then duplicates
the To header (both the possibly empty field the user provided, plus the
one coming from format-patch).  I had a brief look at
git-send-email.perl, and I'm a little confused.

	} elsif (/^(?:To|Cc|Bcc):/i) {
		print "To/Cc/Bcc fields are not interpreted yet, they have been ignored\n";
		next;
	}

This regex doesn't match these headers (is the leading ?: a typo?) so
there is no warning.  But it's important that these headers *not* be
ignored, getting them set automatically is a key feature of the
--notmuch option.  I'm having trouble discerning whether I would cause
problems by just using these headers coming out of format-patch.
Presumably there was a reason why they were (intended to be) explicitly
ignored, and my poor perl skills are not helping.  Could someone
enlighten me?


Jed