Bug #6748 heap_rfirst() doesn't work (and never did!)

range for BETWEEN typo fixed

extra/perror.c

@@ -69,7 +69,7 @@ static HA_ERRORS ha_errlist[]=
 {
   { 120,"Didn't find key on read or update" },
   { 121,"Duplicate key on write or update" },
-  { 123,"Someone has changed the row since it was read; Update with is recoverable" },
+  { 123,"Someone has changed the row since it was read (while the table was locked to prevent it)" },
   { 124,"Wrong index given to function" },
   { 126,"Index file is crashed" },
   { 127,"Record-file is crashed" },

heap/hp_rfirst.c

@@ -52,6 +52,7 @@ int heap_rfirst(HP_INFO *info, byte *record, int inx)
       my_errno=HA_ERR_END_OF_FILE;
       DBUG_RETURN(my_errno);
     }
+    DBUG_ASSERT(0); /* TODO fix it */
     info->current_record=0;
     info->current_hash_ptr=0;
     info->update=HA_STATE_PREV_FOUND;

mysql-test/r/heap.result

@@ -233,3 +233,10 @@ SELECT * FROM t1 WHERE B is not null;
 a	B
 1	1
 DROP TABLE t1;
+CREATE TABLE t1 (pseudo char(35) PRIMARY KEY, date int(10) unsigned NOT NULL) ENGINE=HEAP;
+INSERT INTO t1 VALUES ('massecot',1101106491),('altec',1101106492),('stitch+',1101106304),('Seb Corgan',1101106305),('beerfilou',1101106263),('flaker',1101106529),('joce8',5),('M4vrick',1101106418),('gabay008',1101106525),('Vamp irX',1101106291),('ZoomZip',1101106546),('rip666',1101106502),('CBP ',1101106397),('guezpard',1101106496);
+DELETE FROM t1 WHERE date<1101106546;
+SELECT * FROM t1;
+pseudo	date
+ZoomZip	1101106546
+DROP TABLE t1;

mysql-test/r/range.result

@@ -221,7 +221,7 @@ update t1 set y=x;
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 7 and t1.y+0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	Using where
-1	SIMPLE	t2	range	x	x	5	NULL	4	Using where
+1	SIMPLE	t2	range	x	x	5	NULL	4	Range checked for each record (index map: 0x1)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 7 and t2.x <= t1.y+0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	Using where
@@ -237,7 +237,7 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x between 0 and t1.y;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	Using where
-1	SIMPLE	t2	ALL	x	NULL	NULL	NULL	9	Using where
+1	SIMPLE	t2	ALL	x	NULL	NULL	NULL	9	Range checked for each record (index map: 0x1)
 explain select * from t1, t1 t2 where t1.y = 2 and t2.x >= 0 and t2.x <= t1.y;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
 1	SIMPLE	t1	ref	y	y	5	const	1	Using where

mysql-test/t/heap.test

@@ -174,3 +174,14 @@ 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;
+
+#
+# Bug #6748
+# heap_rfirst() doesn't work (and never did!)
+#
+CREATE TABLE t1 (pseudo char(35) PRIMARY KEY, date int(10) unsigned NOT NULL) ENGINE=HEAP;
+INSERT INTO t1 VALUES ('massecot',1101106491),('altec',1101106492),('stitch+',1101106304),('Seb Corgan',1101106305),('beerfilou',1101106263),('flaker',1101106529),('joce8',5),('M4vrick',1101106418),('gabay008',1101106525),('Vamp irX',1101106291),('ZoomZip',1101106546),('rip666',1101106502),('CBP ',1101106397),('guezpard',1101106496);
+DELETE FROM t1 WHERE date<1101106546;
+SELECT * FROM t1;
+DROP TABLE t1;
+

sql/handler.cc

@@ -953,8 +953,10 @@ int handler::read_first_row(byte * buf, uint primary_key)
   /*
     If there is very few deleted rows in the table, find the first row by
     scanning the table.
+    TODO remove the test for HA_READ_ORDER
   */
-  if (deleted < 10 || primary_key >= MAX_KEY)
+  if (deleted < 10 || primary_key >= MAX_KEY ||
+      !(index_flags(primary_key, 0, 0) & HA_READ_ORDER))
   {
     (void) ha_rnd_init(1);
     while ((error= rnd_next(buf)) == HA_ERR_RECORD_DELETED) ;

sql/sql_select.cc

@@ -2154,7 +2154,7 @@ add_key_field(KEY_FIELD **key_fields,uint and_level, COND *cond,
 
       bool is_const=1;
       for (uint i=0; i<num_values; i++)
-        is_const&= (*value)->const_item();
+        is_const&= value[i]->const_item();
       if (is_const)
         stat[0].const_keys.merge(possible_keys);
       /*