[PATCH V2] parsers: fix invariant bug in find_deepest

[Augie Fackler]

On Fri, Jul 14, 2017 at 01:49:09PM +0200, Sune Foldager wrote:
> # HG changeset patch
> # User Sune Foldager <cryo at cyanite.org>
> # Date 1500032897 -7200
> #      Fri Jul 14 13:48:17 2017 +0200
> # Branch stable
> # Node ID 21158392118c6ffd8c60dd627a338f044726b9cb
> # Parent  c1994c986d77f071e338de35a2c69d7bb87e39a3
> parsers: fix invariant bug in find_deepest

queued, thanks

(Though with a pretty big rebase and a commit message tweak for the
bugzilla bot)