Adds null check for node in HasRangeTableRef (#7604)

DESCRIPTION: Adds null check for node in HasRangeTableRef to prevent errors When executing the query below, users encountered an error due to a null Node object. This PR adds a null check to handle this error. Query: ```sql select ct.conname as constraint_name, a.attname as column_name, fc.relname as foreign_table_name, fns.nspname as foreign_table_schema, fa.attname as foreign_column_name from (SELECT ct.conname, ct.conrelid, ct.confrelid, ct.conkey, ct.contype, ct.confkey, generate_subscripts(ct.conkey, 1) AS s FROM pg_constraint ct ) AS ct inner join pg_class c on c.oid=ct.conrelid inner join pg_namespace ns on c.relnamespace=ns.oid inner join pg_attribute a on a.attrelid=ct.conrelid and a.attnum = ct.conkey[ct.s] left join pg_class fc on fc.oid=ct.confrelid left join pg_namespace fns on fc.relnamespace=fns.oid left join pg_attribute fa on fa.attrelid=ct.confrelid and fa.attnum = ct.confkey[ct.s] where ct.contype='f' and c.relname='table1' and ns.nspname='schemauser' order by fns.nspname, fc.relname, a.attnum ; ``` Error: ``` #0 HasRangeTableRef (node=0x0, varno=varno@entry=0x7ffe18cc3674) at worker/worker_shard_visibility.c:507 507 if (IsA(node, RangeTblRef)) #0 HasRangeTableRef (node=0x0, varno=varno@entry=0x7ffe18cc3674) at worker/worker_shard_visibility.c:507 #1 0x0000561b0aae390e in expression_tree_walker_impl (node=0x561b0d19cc78, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2091 #2 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #3 0x0000561b0aae3e09 in expression_tree_walker_impl (node=0x561b0d19cd68, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=context@entry=0x7ffe18cc3674) at nodeFuncs.c:2405 #4 0x0000561b0aae3945 in expression_tree_walker_impl (node=0x561b0d19d0f8, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2111 #5 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #6 0x0000561b0aae3e09 in expression_tree_walker_impl (node=0x561b0d19cb38, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=context@entry=0x7ffe18cc3674) at nodeFuncs.c:2405 #7 0x0000561b0aae396d in expression_tree_walker_impl (node=0x561b0d19d198, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2127 #8 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #9 0x0000561b0aae3ef7 in expression_tree_walker_impl (node=0x561b0d183e88, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2464 #10 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #11 0x0000561b0aae3ed3 in expression_tree_walker_impl (node=0x561b0d184278, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2460 #12 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #13 0x0000561b0aae3ed3 in expression_tree_walker_impl (node=0x561b0d184668, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2460 #14 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #15 0x0000561b0aae3ed3 in expression_tree_walker_impl (node=0x561b0d184f68, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=0x7ffe18cc3674) at nodeFuncs.c:2460 #16 0x00007f2a73249f26 in HasRangeTableRef (node=<optimized out>, varno=<optimized out>) at worker/worker_shard_visibility.c:513 #17 0x0000561b0aae3e09 in expression_tree_walker_impl (node=0x7f2a68010148, walker=walker@entry=0x7f2a73249f0a <HasRangeTableRef>, context=context@entry=0x7ffe18cc3674) at nodeFuncs.c:2405 #18 0x00007f2a7324a0eb in FilterShardsFromPgclass (node=node@entry=0x561b0d185de8, context=context@entry=0x0) at worker/worker_shard_visibility.c:464 #19 0x00007f2a7324a5ff in HideShardsFromSomeApplications (query=query@entry=0x561b0d185de8) at worker/worker_shard_visibility.c:294 #20 0x00007f2a731ed7ac in distributed_planner (parse=0x561b0d185de8, query_string=0x561b0d009478 "select\n ct.conname as constraint_name,\n a.attname as column_name,\n fc.relname as foreign_table_name,\n fns.nspname as foreign_table_schema,\n fa.attname as foreign_column_name\nfrom\n (S"..., cursorOptions=<optimized out>, boundParams=0x0) at planner/distributed_planner.c:237 #21 0x00007f2a7311a52a in pgss_planner (parse=0x561b0d185de8, query_string=0x561b0d009478 "select\n ct.conname as constraint_name,\n a.attname as column_name,\n fc.relname as foreign_table_name,\n fns.nspname as foreign_table_schema,\n fa.attname as foreign_column_name\nfrom\n (S"..., cursorOptions=2048, boundParams=0x0) at pg_stat_statements.c:953 #22 0x0000561b0ab65465 in planner (parse=parse@entry=0x561b0d185de8, query_string=query_string@entry=0x561b0d009478 "select\n ct.conname as constraint_name,\n a.attname as column_name,\n fc.relname as foreign_table_name,\n fns.nspname as foreign_table_schema,\n fa.attname as foreign_column_name\nfrom\n (S"..., cursorOptions=cursorOptions@entry=2048, boundParams=boundParams@entry=0x0) at planner.c:279 #23 0x0000561b0ac53aa3 in pg_plan_query (querytree=querytree@entry=0x561b0d185de8, query_string=query_string@entry=0x561b0d009478 "select\n ct.conname as constraint_name,\n a.attname as column_name,\n fc.relname as foreign_table_name,\n fns.nspname as foreign_table_schema,\n fa.attname as foreign_column_name\nfrom\n (S"..., cursorOptions=cursorOptions@entry=2048, boundParams=boundParams@entry=0x0) at postgres.c:904 #24 0x0000561b0ac53b71 in pg_plan_queries (querytrees=0x7f2a68012878, query_string=query_string@entry=0x561b0d009478 "select\n ct.conname as constraint_name,\n a.attname as column_name,\n fc.relname as foreign_table_name,\n fns.nspname as foreign_table_schema,\n fa.attname as foreign_column_name\nfrom\n (S"..., cursorOptions=cursorOptions@entry=2048, boundParams=boundParams@entry=0x0) at postgres.c:996 #25 0x0000561b0ac5408e in exec_simple_query ( query_string=query_string@entry=0x561b0d009478 "select\n ct.conname as constraint_name,\n a.attname as column_name,\n fc.relname as foreign_table_name,\n fns.nspname as foreign_table_schema,\n fa.attname as foreign_column_name\nfrom\n (S"...) at postgres.c:1193 #26 0x0000561b0ac56116 in PostgresMain (dbname=<optimized out>, username=<optimized out>) at postgres.c:4637 #27 0x0000561b0abab7a7 in BackendRun (port=port@entry=0x561b0d0caf50) at postmaster.c:4464 #28 0x0000561b0abae969 in BackendStartup (port=port@entry=0x561b0d0caf50) at postmaster.c:4192 #29 0x0000561b0abaeaa6 in ServerLoop () at postmaster.c:1782 ``` Fixes #7603
citusdata · May 28, 2024 · 4e838a4 · 4e838a4
1 parent 035aa6e
commit 4e838a4
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diff --git a/src/backend/distributed/worker/worker_shard_visibility.c b/src/backend/distributed/worker/worker_shard_visibility.c
@@ -504,6 +504,11 @@ FilterShardsFromPgclass(Node *node, void *context)
 static bool
 HasRangeTableRef(Node *node, int *varno)
 {
+	if (node == NULL)
+	{
+		return false;
+	}
+
 	if (IsA(node, RangeTblRef))
 	{
 		RangeTblRef *rangeTblRef = (RangeTblRef *) node;

diff --git a/src/test/regress/expected/system_queries.out b/src/test/regress/expected/system_queries.out
@@ -0,0 +1,33 @@
+-- The following query retrieves the foreign key constraints of the table "pg_dist_background_job"
+-- along with their details. This modification includes a fix for a null pointer exception that occurred
+-- in the "HasRangeTableRef" method of "worker_shard_visibility". The issue was resolved with PR #7604.
+select
+    ct.conname as constraint_name,
+    a.attname as column_name,
+    fc.relname as foreign_table_name,
+    fns.nspname as foreign_table_schema
+from
+    (SELECT ct.conname, ct.conrelid, ct.confrelid, ct.conkey, ct.contype,
+ct.confkey, generate_subscripts(ct.conkey, 1) AS s
+       FROM pg_constraint ct
+    ) AS ct
+    inner join pg_class c on c.oid=ct.conrelid
+    inner join pg_namespace ns on c.relnamespace=ns.oid
+    inner join pg_attribute a on a.attrelid=ct.conrelid and a.attnum =
+ct.conkey[ct.s]
+    left join pg_class fc on fc.oid=ct.confrelid
+    left join pg_namespace fns on fc.relnamespace=fns.oid
+    left join pg_attribute fa on fa.attrelid=ct.confrelid and fa.attnum =
+ct.confkey[ct.s]
+where
+    ct.contype='f'
+     and fc.relname='pg_dist_background_job'
+    and ns.nspname='pg_catalog'
+order by
+    fns.nspname, fc.relname, a.attnum;
+              constraint_name               | column_name |   foreign_table_name   | foreign_table_schema
+---------------------------------------------------------------------
+ pg_dist_background_task_job_id_fkey        | job_id      | pg_dist_background_job | pg_catalog
+ pg_dist_background_task_depend_job_id_fkey | job_id      | pg_dist_background_job | pg_catalog
+(2 rows)
+
diff --git a/src/test/regress/multi_schedule b/src/test/regress/multi_schedule
@@ -79,7 +79,7 @@ test: multi_basic_queries cross_join multi_complex_expressions multi_subquery mu
 test: multi_subquery_complex_reference_clause multi_subquery_window_functions multi_view multi_sql_function multi_prepare_sql
 test: sql_procedure multi_function_in_join row_types materialized_view
 test: multi_subquery_in_where_reference_clause adaptive_executor propagate_set_commands geqo
-test: forcedelegation_functions
+test: forcedelegation_functions system_queries
 # this should be run alone as it gets too many clients
 test: join_pushdown
 test: multi_subquery_union multi_subquery_in_where_clause multi_subquery_misc statement_cancel_error_message

diff --git a/src/test/regress/sql/system_queries.sql b/src/test/regress/sql/system_queries.sql
@@ -0,0 +1,27 @@
+-- The following query retrieves the foreign key constraints of the table "pg_dist_background_job"
+-- along with their details. This modification includes a fix for a null pointer exception that occurred
+-- in the "HasRangeTableRef" method of "worker_shard_visibility". The issue was resolved with PR #7604.
+select
+    ct.conname as constraint_name,
+    a.attname as column_name,
+    fc.relname as foreign_table_name,
+    fns.nspname as foreign_table_schema
+from
+    (SELECT ct.conname, ct.conrelid, ct.confrelid, ct.conkey, ct.contype,
+ct.confkey, generate_subscripts(ct.conkey, 1) AS s
+       FROM pg_constraint ct
+    ) AS ct
+    inner join pg_class c on c.oid=ct.conrelid
+    inner join pg_namespace ns on c.relnamespace=ns.oid
+    inner join pg_attribute a on a.attrelid=ct.conrelid and a.attnum =
+ct.conkey[ct.s]
+    left join pg_class fc on fc.oid=ct.confrelid
+    left join pg_namespace fns on fc.relnamespace=fns.oid
+    left join pg_attribute fa on fa.attrelid=ct.confrelid and fa.attnum =
+ct.confkey[ct.s]
+where
+    ct.contype='f'
+     and fc.relname='pg_dist_background_job'
+    and ns.nspname='pg_catalog'
+order by
+    fns.nspname, fc.relname, a.attnum;