persistent-nodemap: introduce a test to highlight possible race...
persistent-nodemap: introduce a test to highlight possible race
Weakness in the current file caching of the changelog means that a writer can
end up using an outdated docket. This might result in "committed"
persistent-nodemap data from a previous writer to be overwritten by a later
writer. This break the strong "append only" assumption of the persistent nodemap
and can result in confused reader.
The race windows are quite narrow. See the test documentation for details.
The issues is fixed in the next changeset.
Differential Revision:
https://phab.mercurial-scm.org/D11481
