From 0f249fe5f5cb3c83fd8e05743740b35ff5d34196 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 11 Aug 2016 11:22:25 -0400
Subject: [PATCH] Fix busted Assert for CREATE MATVIEW ... WITH NO DATA.

Commit 874fe3aea 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>
---
 src/backend/executor/spi.c            |  8 ++++++--
 src/test/regress/expected/matview.out | 25 +++++++++++++++++++++++++
 src/test/regress/sql/matview.sql      | 14 ++++++++++++++
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 7ccabdb44b2..38de18006de 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -2226,8 +2226,12 @@ _SPI_execute_plan(SPIPlanPtr plan, ParamListInfo paramLI,
 							pg_strtouint64(completionTag + 7, NULL, 10);
 					else
 					{
-						/* Must be an IF NOT EXISTS that did nothing */
-						Assert(ctastmt->if_not_exists);
+						/*
+						 * Must be an IF NOT EXISTS that did nothing, or a
+						 * CREATE ... WITH NO DATA.
+						 */
+						Assert(ctastmt->if_not_exists ||
+							   ctastmt->into->skipData);
 						_SPI_current->processed = 0;
 					}
 
diff --git a/src/test/regress/expected/matview.out b/src/test/regress/expected/matview.out
index 102bf1f155d..e7d0ad1d86d 100644
--- a/src/test/regress/expected/matview.out
+++ b/src/test/regress/expected/matview.out
@@ -557,3 +557,28 @@ REFRESH MATERIALIZED VIEW mvtest_mv_foo;
 REFRESH MATERIALIZED VIEW CONCURRENTLY mvtest_mv_foo;
 DROP OWNED BY regress_user_mvtest CASCADE;
 DROP ROLE regress_user_mvtest;
+-- 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
index a108b6943dc..5f3269def8a 100644
--- a/src/test/regress/sql/matview.sql
+++ b/src/test/regress/sql/matview.sql
@@ -226,3 +226,17 @@ REFRESH MATERIALIZED VIEW mvtest_mv_foo;
 REFRESH MATERIALIZED VIEW CONCURRENTLY mvtest_mv_foo;
 DROP OWNED BY regress_user_mvtest CASCADE;
 DROP ROLE regress_user_mvtest;
+
+-- 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;