Re: bug? illegal text in commit log

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 7, 2020, 21:12 UTC
Message-ID: <xmqqh8022jay.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <c67e59a2-0f81-8311-e14c-f27876e45cf0@web.de>

René Scharfe <l.s.r@web.de> writes:

Show 9 quoted lines

> That's a good idea from a usability point of view.  However, mailinfo()
> parses patches line by line.  It doesn't know the total number of lines
> until it's done.  (It would if the Lines header from RFC 1036 was
> mandatory for emails; RFC 2076 says it's "not standardized for use in
> e-mail".)  It cannot easily go back at that point.
>
> Reading the whole message into a buffer or a temporary file would be an
> option, but that would give up the nice property that patches are
> streamed.

True, but we could do a two-pass approach, perhaps?  That is

 * The first pass does exactly the same as what today's code does,
   PLUS it prepares for the case where we thought the log message
   ended because we saw "diff -" or "Index: " before seeing "---",
   by scanning for the first "---"while running handle_patch().

   If there is no such "oops, a 'diff -' in the log message fooled
   us" event, we complete with what today's code does.

 * But if we detect such a case during the first pass, we run
   ourselves again with the same input and arguments, PLUS an extra,
   new option, which tells us that "we know '---' exists in the
   input and it *is* the patchbreak.  This of course can be done
   only when the standard input is seekable, but builtin/am.c does
   store the mail in a file, so...