Fix crash in error report of invalid tuple lock

My tweak of these error messages in commit c359a1b082 contained the
thinko that a query would always have rowMarks set for a query
containing a locking clause.  Not so: when declaring a cursor, for
instance, rowMarks isn't set at the point we're checking, so we'd be
dereferencing a NULL pointer.

The fix is to pass the lock strength to the function raising the error,
instead of trying to reverse-engineer it.  The result not only is more
robust, but it also seems cleaner overall.

Per report from Robert Haas.

6 files changed, 17 insertions, 0 deletions

diff --git a/src/test/regress/expected/matview.out b/src/test/regress/expected/matview.out
index 5a31fda69fc..ddaa6460953 100644
--- a/src/test/regress/expected/matview.out
+++ b/src/test/regress/expected/matview.out
@@ -292,6 +292,9 @@ NOTICE:  materialized view "no_such_mv" does not exist, skipping
 -- make sure invalid comination of options is prohibited
 REFRESH MATERIALIZED VIEW CONCURRENTLY tvmm WITH NO DATA;
 ERROR:  CONCURRENTLY and WITH NO DATA options cannot be used together
+-- no tuple locks on materialized views
+SELECT * FROM tvvm FOR SHARE;
+ERROR:  cannot lock rows in materialized view "tvvm"
 -- test join of mv and view
 SELECT type, m.totamt AS mtot, v.totamt AS vtot FROM tm m LEFT JOIN tv v USING (type) ORDER BY type;
  type | mtot | vtot 
diff --git a/src/test/regress/expected/portals.out b/src/test/regress/expected/portals.out
index 01152a939d3..aafc6cf5294 100644
--- a/src/test/regress/expected/portals.out
+++ b/src/test/regress/expected/portals.out
@@ -1226,6 +1226,10 @@ DECLARE c1 CURSOR FOR SELECT * FROM uctest;
 DELETE FROM uctest WHERE CURRENT OF c1; -- fail, no current row
 ERROR:  cursor "c1" is not positioned on a row
 ROLLBACK;
+BEGIN;
+DECLARE c1 CURSOR FOR SELECT MIN(f1) FROM uctest FOR UPDATE;
+ERROR:  FOR UPDATE is not allowed with aggregate functions
+ROLLBACK;
 -- WHERE CURRENT OF may someday work with views, but today is not that day.
 -- For now, just make sure it errors out cleanly.
 CREATE TEMP VIEW ucview AS SELECT * FROM uctest;
diff --git a/src/test/regress/expected/union.out b/src/test/regress/expected/union.out
index bf8f1bcaf77..ae690cf9689 100644
--- a/src/test/regress/expected/union.out
+++ b/src/test/regress/expected/union.out
@@ -317,6 +317,8 @@ SELECT q1 FROM int8_tbl EXCEPT ALL SELECT DISTINCT q2 FROM int8_tbl;
               123
 (3 rows)
 
+SELECT q1 FROM int8_tbl EXCEPT ALL SELECT q1 FROM int8_tbl FOR NO KEY UPDATE;
+ERROR:  FOR NO KEY UPDATE is not allowed with UNION/INTERSECT/EXCEPT
 --
 -- Mixed types
 --
diff --git a/src/test/regress/sql/matview.sql b/src/test/regress/sql/matview.sql
index 9d60bbbbe4d..620cbaca151 100644
--- a/src/test/regress/sql/matview.sql
+++ b/src/test/regress/sql/matview.sql
@@ -95,6 +95,9 @@ DROP MATERIALIZED VIEW IF EXISTS no_such_mv;
 -- make sure invalid comination of options is prohibited
 REFRESH MATERIALIZED VIEW CONCURRENTLY tvmm WITH NO DATA;
 
+-- no tuple locks on materialized views
+SELECT * FROM tvvm FOR SHARE;
+
 -- test join of mv and view
 SELECT type, m.totamt AS mtot, v.totamt AS vtot FROM tm m LEFT JOIN tv v USING (type) ORDER BY type;
 
diff --git a/src/test/regress/sql/portals.sql b/src/test/regress/sql/portals.sql
index 02286c4096e..203e6577039 100644
--- a/src/test/regress/sql/portals.sql
+++ b/src/test/regress/sql/portals.sql
@@ -447,6 +447,9 @@ BEGIN;
 DECLARE c1 CURSOR FOR SELECT * FROM uctest;
 DELETE FROM uctest WHERE CURRENT OF c1; -- fail, no current row
 ROLLBACK;
+BEGIN;
+DECLARE c1 CURSOR FOR SELECT MIN(f1) FROM uctest FOR UPDATE;
+ROLLBACK;
 
 -- WHERE CURRENT OF may someday work with views, but today is not that day.
 -- For now, just make sure it errors out cleanly.
diff --git a/src/test/regress/sql/union.sql b/src/test/regress/sql/union.sql
index 6194ce47511..d567cf14819 100644
--- a/src/test/regress/sql/union.sql
+++ b/src/test/regress/sql/union.sql
@@ -109,6 +109,8 @@ SELECT q1 FROM int8_tbl EXCEPT ALL SELECT q2 FROM int8_tbl;
 
 SELECT q1 FROM int8_tbl EXCEPT ALL SELECT DISTINCT q2 FROM int8_tbl;
 
+SELECT q1 FROM int8_tbl EXCEPT ALL SELECT q1 FROM int8_tbl FOR NO KEY UPDATE;
+
 --
 -- Mixed types
 --