test/cql-pytest: add another regression test for reversed-type bug

In commit 544ef2c we fixed a bug where
a reveresed clustering-key order caused problems using a secondary index
because of incorrect type comparison. That commit also included a
regression test for this fix.

However, that fix was incomplete, and improved later in commit
c8653d1. That later fix was labeled
"better safe than sorry", and did not include a test demonstrating
any actual bug, so unsurprisingly we never backported that second
fix to any older branches.

Recently we discovered that missing the second patch does cause real
problems, and this patch includes a test which fails when the first
patch is in, but the second patch isn't (and passes when both patches
are in, and also passes on Cassandra).

Signed-off-by: Nadav Har'El <nyh@scylladb.com>

Closes scylladb#11943

test/cql-pytest/test_secondary_index.py

@@ -207,6 +207,24 @@ def test_paging_with_desc_clustering_order(cql, test_keyspace):
         stmt = SimpleStatement(f"SELECT * FROM {table} WHERE c = 42", fetch_size=1)
         assert len([row for row in cql.execute(stmt)]) == 3
 
+# The following test is similar to the above, except that the reversed type
+# is not of the indexed column itself - but it's still part of the index's
+# materialized view (because it's part of the key), and we use SELECT DISTINCT
+# instead of SELECT. This reproduces Scylla Enterprise issue #2449,
+# and is a regression test for commit c8653d1321ca9ff5963f9e5479372a6000a0f096.
+def test_paging_with_desc_clustering_order2(cql, test_keyspace):
+    schema = 'p1 int, p2 int, c int, primary key ((p1,p2),c)'
+    extra = 'with clustering order by (c desc)'
+    with new_test_table(cql, test_keyspace, schema, extra) as table:
+        cql.execute(f"CREATE INDEX ON {table}(p1)")
+        for i in range(3):
+            cql.execute(f"INSERT INTO {table}(p1,p2,c) VALUES (7, {i}, 42)")
+        stmt = SimpleStatement(f"SELECT p1,p2 FROM {table} WHERE p1 = 7", fetch_size=1)
+        assert len(list(cql.execute(stmt))) == 3
+        # Reproduces Scylla Enterprise issue #2449:
+        stmt = SimpleStatement(f"SELECT DISTINCT p1,p2 FROM {table} WHERE p1 = 7", fetch_size=1)
+        assert len(list(cql.execute(stmt))) == 3
+
 # Test that deleting a base partition works fine, even if it produces a large batch
 # of individual view updates. Refs #8852 - view updates used to be applied with
 # per-partition granularity, but after fixing the issue it's no longer the case,