Automatic recovery from Multiple Merge Candidates error
Summary:
Introduce a recovery codepath when Multiple Merge Candidates error
occurs during Item merging. Since clients generally do not use
merging, this really only happens during ItemSync. In such case we
quitely delete all the conflicting items from the database and reschedule
the collection sync. The next sync should then succeed and bring the
collection into a consistent state.
Note that this does not fix the Multiple Merge Candidates bug - it can
still happen (and we still don't know how), but Akonadi should now be
able to recover from it automatically without user intervention, thus
making this issue less of a PITA.
CCBUG: 338658
Test Plan: Successfuly auto-recovered a broken collection on my setup.
Reviewers: KDE PIM, dfaure
Reviewed By: dfaure
Subscribers: vkrause, dfaure, ngraham, asturmlechner, kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D21455
(cherry picked from commit 8f230d7d7f8a4e2b97273585374a68902b5ef6cf)