Boris Feld <boris.feld@octobus.net> [Wed, 10 Oct 2018 00:50:34 +0200] rev 40693
context: take advantage of `_descendantrev` in introrev if available
Before this changeset, `_descendantrev` was ignored and `introrev` could
return a "wrong" result. I was previously fine because there seems to be no
existing code using both `introrev` and `_descendantrev` at the same time.
However, we would like to change that.