Re: [PATCH] send-email: clarify missing subject error

An input file to the 'git send-email' program is often the output
of 'git format-patch'.  Such a file begins with a UNIX 'From '
line, followed by email headers such as 'From:', 'Date:', and
'Subject:'.  The 'Subject:' line cannot be the first line of
the file in this case, yet it is a valid input.

The only condition that this subroutine flags as an error is when
the file lacks a subject line.  "No 'Subject:' line in '%s'\n" is a
clear message to display and is an improvement over the original.

However, the fact that the first line does not start with
"Subject:" is irrelevant to the basis of the subroutine's
decision to issue an error, I think.

Yeah, that makes sense, so maybe we don't need to focus on it being
the first line, but Subject needs to be there somewhere before the
body.


Harald