Re: Bug in "git am" when the body starts with spaces

From: Jeff King <peff@peff.net>
Date: Apr 2, 2017, 04:18 UTC
Message-ID: <20170402041838.dzkmibc5lq37sm3h@sigill.intra.peff.net>
In-Reply-To: <CA+55aFwmNuvh_ABtnd_uxXv5HjEjN-+HMZGh_u1OjOCa4dbpmg@mail.gmail.com>

On Sat, Apr 01, 2017 at 12:03:44PM -0700, Linus Torvalds wrote:

Show 12 quoted lines

> On Fri, Mar 31, 2017 at 5:52 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > The continuation logic is oddly complex, and I can't follow the logic.
> > But it is completely broken in how it thinks empty lines are somehow
> > "continuations".
> 
> The attached patch seems to work for me. Comments?
> 
> The logic is fairly simple: if we encounter an empty line, and we have
> pending in-body headers, we flush the pending headers, and mark us as
> no longer in header mode.

Hmm. I think this may work. At first I thought it was too strict in always checking inbody_header_accum.len, because we want this to kick in always, whether there's whitespace continuation or not. But that accumulator has to collect preemptively, before it knows if there's continuation. So it will always be non-empty if we've seen _any_ header, and it will remain non-empty as long as we keep parsing (because any time we flush, we do so in order to handle another line).

IOW, I think this implements the state-machine thing I wrote in my earlier email, because the state "are we inside in-body header parsing" is always reflected by having a non-empty accumulator. It is a bit non-obvious though.

-Peff