Fix busted Assert for CREATE MATVIEW ... WITH NO DATA.

tglsfdc · tglsfdc · commit 942ff002f9ee · 2016-08-11T11:22:25.000-04:00
Commit 874fe3a changed the command tag returned for CREATE MATVIEW/CREATE TABLE AS ... WITH NO DATA, but missed that there was code in spi.c that expected the command tag to always be "SELECT". Fortunately, the consequence was only an Assert failure, so this oversight should have no impact in production builds. Since this code path was evidently un-exercised, add a regression test. Per report from Shivam Saxena. Back-patch to 9.3, like the previous commit. Michael Paquier Report: <97218716-480B-4527-B5CD-D08D798A0C7B@dresources.com>
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
@@ -2180,15 +2180,23 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
 				 */
 				if (IsA(stmt, CreateTableAsStmt))
 				{
-					Assert(strncmp(completionTag, "SELECT ", 7) == 0);
-					_SPI_current->processed = strtoul(completionTag + 7,
-													  NULL, 10);
+					CreateTableAsStmt *ctastmt = (CreateTableAsStmt *) stmt;
+
+					if (strncmp(completionTag, "SELECT ", 7) == 0)
+						_SPI_current->processed =
+							strtoul(completionTag + 7, NULL, 10);
+					else
+					{
+						/* Must be a CREATE ... WITH NO DATA */
+						Assert(ctastmt->into->skipData);
+						_SPI_current->processed = 0;
+					}
 
 					/*
 					 * For historical reasons, if CREATE TABLE AS was spelled
 					 * as SELECT INTO, return a special return code.
 					 */
-					if (((CreateTableAsStmt *) stmt)->is_select_into)
+					if (ctastmt->is_select_into)
 						res = SPI_OK_SELINTO;
 				}
 				else if (IsA(stmt, CopyStmt))
diff --git a/src/test/regress/expected/matview.out b/src/test/regress/expected/matview.out
@@ -477,3 +477,28 @@ SELECT * FROM mv_v;
 
 DROP TABLE v CASCADE;
 NOTICE:  drop cascades to materialized view mv_v
+-- make sure that create WITH NO DATA works via SPI
+BEGIN;
+CREATE FUNCTION mvtest_func()
+  RETURNS void AS $$
+BEGIN
+  CREATE MATERIALIZED VIEW mvtest1 AS SELECT 1 AS x;
+  CREATE MATERIALIZED VIEW mvtest2 AS SELECT 1 AS x WITH NO DATA;
+END;
+$$ LANGUAGE plpgsql;
+SELECT mvtest_func();
+ mvtest_func 
+-------------
+ 
+(1 row)
+
+SELECT * FROM mvtest1;
+ x 
+---
+ 1
+(1 row)
+
+SELECT * FROM mvtest2;
+ERROR:  materialized view "mvtest2" has not been populated
+HINT:  Use the REFRESH MATERIALIZED VIEW command.
+ROLLBACK;
diff --git a/src/test/regress/sql/matview.sql b/src/test/regress/sql/matview.sql
@@ -166,3 +166,17 @@ DELETE FROM v WHERE EXISTS ( SELECT * FROM mv_v WHERE mv_v.a = v.a );
 SELECT * FROM v;
 SELECT * FROM mv_v;
 DROP TABLE v CASCADE;
+
+-- make sure that create WITH NO DATA works via SPI
+BEGIN;
+CREATE FUNCTION mvtest_func()
+  RETURNS void AS $$
+BEGIN
+  CREATE MATERIALIZED VIEW mvtest1 AS SELECT 1 AS x;
+  CREATE MATERIALIZED VIEW mvtest2 AS SELECT 1 AS x WITH NO DATA;
+END;
+$$ LANGUAGE plpgsql;
+SELECT mvtest_func();
+SELECT * FROM mvtest1;
+SELECT * FROM mvtest2;
+ROLLBACK;
