Don't call PostProcessUtility for local commands

It is intended only to aid in processing of distributed DDL commands,
but as written could execute during local CREATE INDEX CONCURRENTLY
commands.

src/backend/distributed/executor/multi_utility.c

@@ -395,7 +395,11 @@ multi_ProcessUtility(Node *parsetree,
 	standard_ProcessUtility(parsetree, queryString, context,
 							params, dest, completionTag);
 
+	/* don't run post-process code for local commands */
+	if (ddlJobs != NIL)
+	{
 		PostProcessUtility(parsetree);
+	}
 
 	if (commandMustRunAsOwner)
 	{

src/test/regress/expected/multi_index_statements.out

@@ -92,6 +92,10 @@ CREATE INDEX IF NOT EXISTS lineitem_orderkey_index on index_test_hash(a);
 NOTICE:  relation "lineitem_orderkey_index" already exists, skipping
 -- Verify that we can create indexes concurrently
 CREATE INDEX CONCURRENTLY lineitem_concurrently_index ON lineitem (l_orderkey);
+-- Verify that no-name local CREATE INDEX CONCURRENTLY works
+CREATE TABLE local_table (id integer, name text);
+CREATE INDEX CONCURRENTLY ON local_table(id);
+DROP TABLE local_table;
 -- Verify that all indexes got created on the master node and one of the workers
 SELECT * FROM pg_indexes WHERE tablename = 'lineitem' or tablename like 'index_test_%' ORDER BY indexname;
  schemaname |    tablename     |             indexname              | tablespace |                                                      indexdef                                                       

src/test/regress/sql/multi_index_statements.sql

@@ -66,6 +66,11 @@ CREATE INDEX IF NOT EXISTS lineitem_orderkey_index on index_test_hash(a);
 -- Verify that we can create indexes concurrently
 CREATE INDEX CONCURRENTLY lineitem_concurrently_index ON lineitem (l_orderkey);
 
+-- Verify that no-name local CREATE INDEX CONCURRENTLY works
+CREATE TABLE local_table (id integer, name text);
+CREATE INDEX CONCURRENTLY ON local_table(id);
+DROP TABLE local_table;
+
 -- Verify that all indexes got created on the master node and one of the workers
 SELECT * FROM pg_indexes WHERE tablename = 'lineitem' or tablename like 'index_test_%' ORDER BY indexname;
 \c - - - :worker_1_port