Just to confirm that this works correctly, because I broke it a few
times in different ways while working on T321121.
In this scenario, discussiontools_item_revisions contains rows for
the oldest and newest revisions of pages containing each comment
distinguishable by name, as well as extra rows for the newest
revisions of comments indistinguishable by name, so that they can
be looked up by ID.
Change-Id: Ic8450a6b082ed343dd633d3a43c50696b5d6d2bb
Use revision IDs to break the tie, consistently with MediaWiki (see
RevisionStore::getRelativeRevision) instead of assuming that the
revision we're processing now is somehow both older *and* newer than
the other one (the mind boggles how that ever made sense to me).
Change-Id: I9f1a07124301a36be68578d908353b72f0442c00
discussiontools_item_pages row itp_id=5 has incorrect
itp_oldest_revision_id. It should point to the older of the two
revisions with the same time, but it points to the newer one.
discussiontools_item_revisions row is missing.
Depends-On: I56f0e161e5438d5f77b7d53d4db7411f90f97d05
Change-Id: I61ed42515891a84729455a7a32c98276c7cacd40
