Re: Bug Report: Multi-line trailers containing empty lines break parsing

>
> On Tue, Mar 23, 2021 at 6:39 PM Junio C Hamano <gitster@pobox.com> wrote:
> >
> > Christian Couder <christian.couder@gmail.com> writes:
> >
> > > So I thought that blank lines should not appear in the trailers. And
> > > if any appears, it means that the trailers should start after the last
> > > blank line.
> >
> > I think that is a good principle to stick to.
> >
> > >> >  - if the second "multi:" trailer did not have the funny blank line
> > >> >    before "_two", the expected output would still be "multi:"
> > >> >    followed by "one two three", iow, the line after the second
> > >> >    "multi: one" is a total no-op?  If we added many more " \n" lines
> > >> >    there, they are all absorbed and ignored?  It somehow feels wrong
> > >>
> > >> That's definitely the outcome of this patch, but I agree it feels wrong.
> > >> I'm not sure that we define the behavior that strictly in
> > >> git-interpret-trailers(1), so we have some wiggle room, I guess.
> > >
> > > Any patch to relax how blank lines and other aspects of trailers
> > > parsing in my opinion should come with some documentation change to
> > > explain what we now accept and what we don't accept, and also tests to
> > > enforce that.
> >
> > OK.  But do we document clearly what we accept and we don't before
> > any change?
>
> Maybe it's not enough, but the doc already has the following:
>
> ------
> Existing trailers are extracted from the input message by looking for
> a group of one or more lines that (i) is all trailers, or (ii) contains at
> least one Git-generated or user-configured trailer and consists of at
> least 25% trailers.
> The group must be preceded by one or more empty (or whitespace-only) lines.
> The group must either be at the end of the message or be the last
> non-whitespace lines before a line that starts with '---' (followed by a
> space or the end of the line). Such three minus signs start the patch
> part of the message. See also `--no-divider` below.
>
> When reading trailers, there can be whitespaces after the
> token, the separator and the value. There can also be whitespaces
> inside the token and the value. The value may be split over multiple lines with
> each subsequent line starting with whitespace, like the "folding" in RFC 822.
> ------