The incremental reader selector maintains an unordered_set of
sstables that are already engaged, and uses std::views::filter
to filter those out. It adds the sstable under consideration to the
set, and if addition failed (because it's already in) then it
filters it out.
This breaks if the filter view is executed twice - the first pass
will add every sstable to the set, and the second will consider
every sstable already filtered. This is what happens with
libstdc++ 15 (due to the addition of vector(from_range_t) constructor),
which uses the first pass to calculate the vector size
and the second pass to insert the elements into a correctly-sized
vector.
Fix by open-coding the loop.
Closes scylladb/scylladb#23597
(cherry picked from commit ac3d25eb44)
Fixes#26247
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
451ae85b38