Re: [RFC PATCH 2/4] range-diff: don't remove funcname from inner diff

> On 04/15, Johannes Schindelin wrote:
>
> > On Sun, 14 Apr 2019, Eric Sunshine wrote:
> >
> > > On Sun, Apr 14, 2019 at 5:09 PM Thomas Gummerer <t.gummerer@gmail.com> wrote:
> > > > [...]
> > > > However it can still be useful to have the function name that 'git
> > > > diff' extracts as additional context for the change.
> > > > [...]
> > > > Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
> > > > ---
> > > > diff --git a/range-diff.c b/range-diff.c
> > > > @@ -102,9 +102,12 @@ static int read_patches(const char *range, struct string_list *list)
> > > > +               } else if (starts_with(line.buf, "@@ ")) {
> > > > +                       char *skip_lineno = strstr(line.buf + 3, "@@");
> > > > +                       strbuf_remove(&line, 0, skip_lineno - line.buf);
> > >
> > > It makes me a bit uncomfortable that this is not checking for NULL
> > > return from strstr() before doing pointer arithmetic (even though the
> > > input is presumably machine-generated).
> > >
> > >     if (!skip_lineno)
> > >         BUG(...);
> >
> > Good point, but maybe we should not go so far as to declare this a bug,
> > and fall back to removing everything bug the initial two `at` characters
> > instead?
>
> I like declaring this a bug.  We are after all parsing
> machine-generated output, that does come from git (which is why I
> neglected the NULL checking in the first place).  If that second "@@"
> is not there it's definitely a bug somewhere in the diff machinery,
> I'd say.

> Note that the "@@" also couldn't come from anywhere else, the diff
> header has a well defined format and so does the metadata.  The diff
> itself is prefixed with '<', '>' and '#' in this case, and the commit
> message is also prefixed with four spaces.  So if this breaks
> somewhere I'd rather hear about it loudly, than let users potentially
> get wrong output because we missed something somewhere.