Currently, if there is a fragment in _ready and _out_of_range was set
after row end was consumer, push_ready_fragments() would return
without emitting partition_end.
This is problematic once we make consume_row_start() emit
partiton_start directly, because we will want to assume that all
fragments for the previous partition are emitted by then. If they're
not, then we'd emit partition_start before partition_end for the
previous partition. The fix is to make sure that
push_ready_fragments() emits everything.
Fixes#4786
(cherry picked from commit 9b8ac5ecbc)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
d77aaada86