Junio wrote:
> Junio C Hamano <gitster@xxxxxxxxx> writes:
>
> > Mischa POSLAWSKY <git@xxxxxxxx> writes:
> >
> >> Formatting $(taggername) on headerless tags such as v0.99 in Git
> >> causes a SIGABRT with error "munmap_chunk(): invalid pointer",
> >> because of an oversight in commit f0062d3b74 (ref-filter: free
> >> item->value and item->value->s, 2018-10-19).
> >>
> >> Signed-off-by: Mischa POSLAWSKY <git@xxxxxxxx>
> >> ---
> >> If I understand correctly, such tags cannot be produced normally anymore.
> >> Therefore I'm unsure how to make tests, and if that is even warranted.
> >
> > Thanks for spotting.
> >
> > I am not sure if the approach taken by this patch is the right one,
> > though. I didn't follow the call/dataflow thoroughly, but if we
> > replace unfree-able "" with NULL in these places, wouldn't
> > fill_missing_values() take care of them?
>
> I think replacing these "" with NULL would be safe, but there are
> many places that return xstrdup("") from inside the callees of
> populate_value(), so the patch presented here would be more
> consistent with the current practice, I think.
Indeed, I just copied the existing style. Returning NULL seems to work,
but not something I'm confident to clean up here.
> So let's take the patch as is, at least for now. Thanks.
Thank you!
> >> ref-filter.c | 6 +++---
> >> 1 file changed, 3 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/ref-filter.c b/ref-filter.c
> >> index f27cfc8c3e..7338cfc671 100644
> >> --- a/ref-filter.c
> >> +++ b/ref-filter.c
> >> @@ -1028,7 +1028,7 @@ static const char *copy_name(const char *buf)
> >> if (!strncmp(cp, " <", 2))
> >> return xmemdupz(buf, cp - buf);
> >> }
> >> - return "";
> >> + return xstrdup("");
> >> }
> >>
> >> static const char *copy_email(const char *buf)
> >> @@ -1036,10 +1036,10 @@ static const char *copy_email(const char *buf)
> >> const char *email = strchr(buf, '<');
> >> const char *eoemail;
> >> if (!email)
> >> - return "";
> >> + return xstrdup("");
> >> eoemail = strchr(email, '>');
> >> if (!eoemail)
> >> - return "";
> >> + return xstrdup("");
> >> return xmemdupz(email, eoemail + 1 - email);
> >> }
