Bug#6298 (LIMIT #, -1 no longer works to set start with no end limit)

With MySQL 3.23 and 4.0, the syntax 'LIMIT N, -1' is accepted, and returns
all the rows located after row N. This behavior, however, is not the
intended result, and defeats the purpose of LIMIT, which is to constrain
the size of a result set.

With MySQL 4.1 and later, this construct is correctly detected as a syntax
error.

This fix does not change the production code, and only adds a new test case
to improve test coverage in this area, to enforce in the test suite the
intended behavior.

mysql-test/r/select.result

@@ -3611,3 +3611,9 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t2	range	si,ai	si	5	NULL	2	Using where
 1	SIMPLE	t3	eq_ref	PRIMARY,ci	PRIMARY	4	test.t2.a	1	Using where
 DROP TABLE t1,t2,t3;
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1(a int);
+INSERT into t1 values (1), (2), (3);
+SELECT * FROM t1 LIMIT 2, -1;
+ERROR 42000: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '-1' at line 1
+DROP TABLE t1;

mysql-test/t/select.test

@@ -3092,3 +3092,23 @@ SELECT t3.a FROM t1,t2,t3
         t3.c IN ('bb','ee');
 
 DROP TABLE t1,t2,t3;
+
+#
+# Bug#6298: LIMIT #, -1 no longer works to set start with no end limit
+#
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1(a int);
+INSERT into t1 values (1), (2), (3);
+
+# LIMIT N, -1 was accepted by accident in 4.0, but was not intended.
+# This test verifies that this illegal construct is now properly detected.
+
+--error ER_PARSE_ERROR
+SELECT * FROM t1 LIMIT 2, -1;
+
+DROP TABLE t1;
+