Fixed wrong range test code for HEAP tables. This caused a crash when doing a...

Fixed wrong range test code for HEAP tables. This caused a crash when doing a range test with a key that didn't have lower or upper bound (Bug #6082)
More test cases

mysql-test/r/heap.result

@@ -227,3 +227,9 @@ SELECT MAX(job_title_id) FROM job_titles;
 MAX(job_title_id)
 NULL
 DROP TABLE job_titles;
+CREATE TABLE t1 (a INT NOT NULL, B INT, KEY(B)) ENGINE=HEAP;
+INSERT INTO t1 VALUES(1,1), (1,NULL);
+SELECT * FROM t1 WHERE B is not null;
+a	B
+1	1
+DROP TABLE t1;

mysql-test/r/key.result

@@ -296,4 +296,12 @@ Table	Op	Msg_type	Msg_text
 test.t1	check	status	OK
 select c1 from t1 where c2='\Z\Z\Z\Z';
 c1
+truncate table t1;
+insert into t1 values(1,"aaaa"),(2,"aaab"),(3,"aaac"),(4,"aaccc");
+delete from t1 where c1=3;
+delete from t1 where c1=1;
+delete from t1 where c1=4;
+check table t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
 drop table t1;

mysql-test/r/ps.result

@@ -450,3 +450,9 @@ found_rows()
 10
 deallocate prepare stmt;
 drop table t1;
+CREATE TABLE t1 (N int, M tinyint);
+INSERT INTO t1 VALUES (1,0),(1,0),(2,0),(2,0),(3,0);
+PREPARE stmt FROM 'UPDATE t1 AS P1 INNER JOIN (SELECT N FROM t1 GROUP BY N HAVING COUNT(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2';
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;

mysql-test/t/heap.test

@@ -164,3 +164,13 @@ CREATE TABLE `job_titles` (
 SELECT MAX(job_title_id) FROM job_titles;
 
 DROP TABLE job_titles;
+
+#
+# Test of delete with NOT NULL
+# (Bug #6082)
+#
+
+CREATE TABLE t1 (a INT NOT NULL, B INT, KEY(B)) ENGINE=HEAP;
+INSERT INTO t1 VALUES(1,1), (1,NULL);
+SELECT * FROM t1 WHERE B is not null;
+DROP TABLE t1;

mysql-test/t/key.test

@@ -272,5 +272,16 @@ select c1 from t1 where c2='\Z\Z\Z\Z';
 DELETE FROM t1 WHERE (c1 = 3);
 check table t1;
 select c1 from t1 where c2='\Z\Z\Z\Z';
+
+#
+# test delete of keys in a different order
+#
+truncate table t1;
+insert into t1 values(1,"aaaa"),(2,"aaab"),(3,"aaac"),(4,"aaccc");
+delete from t1 where c1=3;
+delete from t1 where c1=1;
+delete from t1 where c1=4;
+check table t1;
+
 drop table t1;
 

mysql-test/t/ps.test

@@ -449,3 +449,16 @@ execute stmt;
 select found_rows();
 deallocate prepare stmt;
 drop table t1;
+
+#
+# Bug#6047 "permission problem when executing mysql_stmt_execute with derived
+# table"
+#
+
+CREATE TABLE t1 (N int, M tinyint); 
+INSERT INTO t1 VALUES (1,0),(1,0),(2,0),(2,0),(3,0);
+PREPARE stmt FROM 'UPDATE t1 AS P1 INNER JOIN (SELECT N FROM t1 GROUP BY N HAVING COUNT(M) > 1) AS P2 ON P1.N = P2.N SET P1.M = 2';
+EXECUTE stmt;
+DEALLOCATE PREPARE stmt;
+DROP TABLE t1;
+

sql/ha_heap.cc

@@ -378,7 +378,8 @@ ha_rows ha_heap::records_in_range(uint inx, key_range *min_key,
   if (key->algorithm == HA_KEY_ALG_BTREE)
     return hp_rb_records_in_range(file, inx, min_key, max_key);
 
-  if (min_key->length != max_key->length ||
+  if (!min_key || !max_key ||
+      min_key->length != max_key->length ||
       min_key->length != key->key_length ||
       min_key->flag != HA_READ_KEY_EXACT ||
       max_key->flag != HA_READ_AFTER_KEY)