dirstate: make sure the dirstate is loaded before the changelog (issue6303)...
dirstate: make sure the dirstate is loaded before the changelog (issue6303)
Before this change, it was possible for the changelog to be loaded before the
dirstate. If a transaction happens betwen the changelog and dirstate reading,
the dirstate can up end poitning toward a revision not existing in the (olded)
changelog. This lead to a warning.
With this revision, we preload the dirstate parent before reading the changelog.
This has a negligible performance impact on performance for all case we are
tracking.
Differential Revision:
https://phab.mercurial-scm.org/D8528
