Currently the handling of partition tombstones is broken in multiple
ways:
* The partition-tombstone is lost when the bucket is calculated for its
timestamp (due to a misplaced `std::exchange()`).
* When the `partition_start` fragment (containing the partition
tombstone) is actually written to the bucket we emit another
`partition_start` fragment before it because the bucket has not seen
that partition before and we fail to notice that we are actually writing
the partition header.
This bug was allowed to fly under the radar because the unit test was
accidentally not creating partition tombstones in the generated data
(due to a mistake). It was discovered while working on unit tests for
another test and fixing the data generation function to actually
generate partition tombstones.
This patch fixes both problems in the handling of partition tombstones
but it doesn't yet fixes the test. That is deferred until the patch
series which uncovered this bug is merged to avoid merge conflicts.
The other series mentioned here is: [PATCH v6 00/15] compaction: allow
collecting purged data
Fixes: #4683
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20190710092427.122623-1-bdenes@scylladb.com>
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