Pierre-Yves David <pierre-yves.david@octobus.net> [Sun, 03 Nov 2019 00:01:09 +0100] rev 43582
index: add a `has_node` method (API)
The new `index.has_node(node)` is to be preferred over:
`node in index.nodemap`.
This get us closer to be able to remove the `nodemap` attribute of the index.
Differential Revision: https://phab.mercurial-scm.org/D7322