Re: Odd git overrflow bug?

On Sun, Jul 10, 2016 at 2:05 PM, Linus Torvalds
[off-list ref] wrote:

I'm getting "extra" being -1 in strbuf_grow(). Let me dog deeper.

"dog deeper"? My typing skills are deteriorating.

Anyway, I dug deeper, and the reason is that "tabwidth" is -1, and then

 pretty.c:1669: strbuf_add_tabexpand():

        strbuf_addchars(sb, ' ', tabwidth - (width % tabwidth));

ends up having the number be -1.

I'm not sure why it doesn't happen in current git master, because that
function is the same, and the logic around expand_tabs_in_log looks
similar too.

That all came from

    fe37a9c586a6 (:pretty: allow tweaking tabwidth in --expand-tabs")

and I suspect the code just needs to protect against negative or zero,
rather than just zero.

Junio?

              Linus