When stopping the read, the multishard reader will dismantle the
compaction state, pushing back (unpopping) the currently processed
partition's header to its originating reader. This ensures that if the
reader stops in the middle of a partition, on the next page the
partition-header is re-emitted as the compactor (and everything
downstream from it) expects.
It can happen however that there is nothing more for the current
partition in the reader and the next fragment is another partition.
Since we only push back the partition header (without a partition-end)
this can result in two partitions being emitted without being separated
by a partition end.
We could just add the missing partition-end when needed but it is
pointless, if the partition has no more data, just drop the header, we
won't need it on the next page.
The missing partition-end can generate an "IDL frame truncated" message
as it ends up causing the query result writer to create a corrupt
partition entry.
Fixes: https://github.com/scylladb/scylla/issues/9482Closes#11137
* github.com:scylladb/scylladb:
test/cql-pytest: add regression test for "IDL frame truncated" error
query: query_result_builder: add check for missing partition-end
mutation_compactor: detach_state(): make it no-op if partition was exhausted
querier: use full_position in shard_mutation_querier