Issue ERROR if FREEZE mode can't be honored by COPY

Previously non-honored FREEZE mode was ignored.  This also issues an
appropriate error message based on the cause of the failure, per
suggestion from Tom.  Additional regression test case added.

2 files changed, 16 insertions, 11 deletions

diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 78c601fd9b..5777b24274 100644
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -334,22 +334,20 @@ SELECT * FROM vistest;
 COMMIT;
 TRUNCATE vistest;
 COPY vistest FROM stdin CSV FREEZE;
+ERROR:  cannot perform FREEZE because the table was not created or truncated in the current transaction
+BEGIN;
+TRUNCATE vistest;
+SAVEPOINT s1;
+COPY vistest FROM stdin CSV FREEZE;
+ERROR:  cannot perform FREEZE because of transaction activity after table creation or truncation
+COMMIT;
 BEGIN;
 INSERT INTO vistest VALUES ('z');
 SAVEPOINT s1;
 TRUNCATE vistest;
 ROLLBACK TO SAVEPOINT s1;
 COPY vistest FROM stdin CSV FREEZE;
-SELECT * FROM vistest;
- a  
-----
- p
- g
- z
- d3
- e
-(5 rows)
-
+ERROR:  cannot perform FREEZE because the table was not created or truncated in the current transaction
 COMMIT;
 CREATE FUNCTION truncate_in_subxact() RETURNS VOID AS
 $$
diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 55568e68e4..c46128b38a 100644
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -234,6 +234,14 @@ p
 g
 \.
 BEGIN;
+TRUNCATE vistest;
+SAVEPOINT s1;
+COPY vistest FROM stdin CSV FREEZE;
+m
+k
+\.
+COMMIT;
+BEGIN;
 INSERT INTO vistest VALUES ('z');
 SAVEPOINT s1;
 TRUNCATE vistest;
@@ -242,7 +250,6 @@ COPY vistest FROM stdin CSV FREEZE;
 d3
 e
 \.
-SELECT * FROM vistest;
 COMMIT;
 CREATE FUNCTION truncate_in_subxact() RETURNS VOID AS
 $$