142336ca53
Due to an error in transforming the above routine, readers who have <= a
buffer worth of content are dropped without consuming them.
This is due to the outer consume loop being conditioned on
`is_end_of_stream()`, which will be set for readers that eagerly
pre-fill their buffer and also have no more data then what is in their
buffer.
Change the condition to also check for `is_buffer_empty()` and only drop
the reader if both of these are true.
Fixes: #9594
Tests: unit(mutation_writer_test --repeat=200, dev)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20211108092923.104504-1-bdenes@scylladb.com>
(cherry picked from commit 4b6c0fe592)