Merge pull request ClickHouse#57048 from ClickHouse/vdimir/pmj_crash_…

…57016 Fix Nullptr dereference in partial merge join with joined_subquery_re…
BetterStackHQ · Nov 22, 2023 · 3463d9a · 3463d9a
2 parents d0653f2 + ee4d5d7
commit 3463d9a
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Showing 3 changed files with 45 additions and 2 deletions.
diff --git a/src/Interpreters/MergeJoin.cpp b/src/Interpreters/MergeJoin.cpp
@@ -530,16 +530,16 @@ MergeJoin::MergeJoin(std::shared_ptr<TableJoin> table_join_, const Block & right
     addConditionJoinColumn(right_sample_block, JoinTableSide::Right);
     JoinCommon::splitAdditionalColumns(key_names_right, right_sample_block, right_table_keys, right_columns_to_add);
 
+    const NameSet required_right_keys = table_join->requiredRightKeys();
     for (const auto & right_key : key_names_right)
     {
-        if (right_sample_block.getByName(right_key).type->lowCardinality())
+        if (required_right_keys.contains(right_key) && right_table_keys.getByName(right_key).type->lowCardinality())
             lowcard_right_keys.push_back(right_key);
     }
 
     JoinCommon::convertToFullColumnsInplace(right_table_keys);
     JoinCommon::convertToFullColumnsInplace(right_sample_block, key_names_right);
 
-    const NameSet required_right_keys = table_join->requiredRightKeys();
     for (const auto & column : right_table_keys)
         if (required_right_keys.contains(column.name))
             right_columns_to_add.insert(ColumnWithTypeAndName{nullptr, column.type, column.name});

diff --git a/tests/queries/0_stateless/02918_join_pm_lc_crash.reference b/tests/queries/0_stateless/02918_join_pm_lc_crash.reference
@@ -0,0 +1,12 @@
+0
+
+0
+0
+
+0
+0
+
+\N
+0
+
+\N
diff --git a/tests/queries/0_stateless/02918_join_pm_lc_crash.sql b/tests/queries/0_stateless/02918_join_pm_lc_crash.sql
@@ -0,0 +1,31 @@
+
+SET joined_subquery_requires_alias = 0, join_algorithm = 'partial_merge';
+
+SET allow_experimental_analyzer = 0, join_use_nulls = 0;
+
+SELECT * FROM (SELECT dummy AS val FROM system.one)
+JOIN (SELECT toLowCardinality(toNullable(dummy)) AS val
+FROM system.one GROUP BY val WITH TOTALS)
+USING (val);
+
+SET allow_experimental_analyzer = 0, join_use_nulls = 1;
+
+SELECT * FROM (SELECT dummy AS val FROM system.one)
+JOIN (SELECT toLowCardinality(toNullable(dummy)) AS val
+FROM system.one GROUP BY val WITH TOTALS)
+USING (val);
+
+SET allow_experimental_analyzer = 1, join_use_nulls = 0;
+
+SELECT * FROM (SELECT dummy AS val FROM system.one)
+JOIN (SELECT toLowCardinality(toNullable(dummy)) AS val
+FROM system.one GROUP BY val WITH TOTALS)
+USING (val);
+
+SET allow_experimental_analyzer = 1, join_use_nulls = 1;
+
+SELECT * FROM (SELECT dummy AS val FROM system.one)
+JOIN (SELECT toLowCardinality(toNullable(dummy)) AS val
+FROM system.one GROUP BY val WITH TOTALS)
+USING (val);
+