Add a test for #10893

tests/queries/0_stateless/01719_join_timezone.reference

+2020-05-13 13:38:45	2020-05-13 16:38:45
+2020-05-13 13:38:45	2020-05-13 16:38:45
+2020-05-13 13:38:45	2020-05-13 16:38:45

tests/queries/0_stateless/01719_join_timezone.sql

+DROP TABLE IF EXISTS test;
+
+CREATE TABLE test (timestamp DateTime('UTC'), i UInt8) Engine=MergeTree() PARTITION BY toYYYYMM(timestamp) ORDER BY (i);
+INSERT INTO test values ('2020-05-13 16:38:45', 1);
+
+SELECT
+    toTimeZone(timestamp, 'America/Sao_Paulo') AS converted,
+    timestamp AS original
+FROM test
+LEFT JOIN (SELECT 2 AS x) AS anything ON x = i
+WHERE timestamp >= toDateTime('2020-05-13T00:00:00', 'America/Sao_Paulo');
+
+/* This was incorrect result in previous ClickHouse versions:
+┌─converted───────────┬─original────────────┐
+│ 2020-05-13 16:38:45 │ 2020-05-13 16:38:45 │ <-- toTimeZone is ignored.
+└─────────────────────┴─────────────────────┘
+*/
+
+SELECT
+    toTimeZone(timestamp, 'America/Sao_Paulo') AS converted,
+    timestamp AS original
+FROM test
+-- LEFT JOIN (SELECT 2 AS x) AS anything ON x = i -- Removing the join fixes the issue.
+WHERE timestamp >= toDateTime('2020-05-13T00:00:00', 'America/Sao_Paulo');
+
+/*
+┌─converted───────────┬─original────────────┐
+│ 2020-05-13 13:38:45 │ 2020-05-13 16:38:45 │ <-- toTimeZone works.
+└─────────────────────┴─────────────────────┘
+*/
+
+SELECT
+    toTimeZone(timestamp, 'America/Sao_Paulo') AS converted,
+    timestamp AS original
+FROM test
+LEFT JOIN (SELECT 2 AS x) AS anything ON x = i
+WHERE timestamp >= '2020-05-13T00:00:00'; -- Not using toDateTime in the WHERE also fixes the issue.
+
+/*
+┌─converted───────────┬─original────────────┐
+│ 2020-05-13 13:38:45 │ 2020-05-13 16:38:45 │ <-- toTimeZone works.
+└─────────────────────┴─────────────────────┘
+*/
+
+DROP TABLE test;