Merge mysql.com:/home/mydev/mysql-4.1-bug14980

into  mysql.com:/home/mydev/mysql-5.0-bug14980

include/my_base.h

@@ -399,7 +399,7 @@ enum ha_base_keytype {
 #define HA_STATE_BUFF_SAVED	512	/* If current keybuff is info->buff */
 #define HA_STATE_ROW_CHANGED	1024	/* To invalide ROW cache */
 #define HA_STATE_EXTEND_BLOCK	2048
-#define HA_STATE_RNEXT_SAME	4096	/* rnext_same was called */
+#define HA_STATE_RNEXT_SAME	4096	/* rnext_same occupied lastkey2 */
 
 /* myisampack expects no more than 32 field types. */
 enum en_fieldtype {

myisam/mi_delete.c

@@ -88,6 +88,8 @@ int mi_delete(MI_INFO *info,const byte *record)
                 _mi_make_key(info,i,old_key,record,info->lastpos)))
           goto err;
       }
+      /* The above changed info->lastkey2. Inform mi_rnext_same(). */
+      info->update&= ~HA_STATE_RNEXT_SAME;
     }
   }
 

myisam/mi_key.c

@@ -444,6 +444,10 @@ static int _mi_put_key_in_record(register MI_INFO *info, uint keynr,
 	     (char*) &blob_ptr,sizeof(char*));
       memcpy(blob_ptr,key,length);
       blob_ptr+=length;
+
+      /* The above changed info->lastkey2. Inform mi_rnext_same(). */
+      info->update&= ~HA_STATE_RNEXT_SAME;
+
       _my_store_blob_length(record+keyseg->start,
 			    (uint) keyseg->bit_start,length);
       key+=length;

myisam/mi_rnext_same.c

@@ -40,7 +40,7 @@ int mi_rnext_same(MI_INFO *info, byte *buf)
 
   if (info->s->concurrent_insert)
     rw_rdlock(&info->s->key_root_lock[inx]);
-    
+
   switch (keyinfo->key_alg)
   {
 #ifdef HAVE_RTREE_KEYS
@@ -102,4 +102,4 @@ int mi_rnext_same(MI_INFO *info, byte *buf)
     DBUG_RETURN(0);
   }
   DBUG_RETURN(my_errno);
-} /* mi_rnext */
+} /* mi_rnext_same */

myisam/mi_unique.c

@@ -30,6 +30,9 @@ my_bool mi_check_unique(MI_INFO *info, MI_UNIQUEDEF *def, byte *record,
   mi_unique_store(record+key->seg->start, unique_hash);
   _mi_make_key(info,def->key,key_buff,record,0);
 
+  /* The above changed info->lastkey2. Inform mi_rnext_same(). */
+  info->update&= ~HA_STATE_RNEXT_SAME;
+
   if (_mi_search(info,info->s->keyinfo+def->key,key_buff,MI_UNIQUE_HASH_LENGTH,
 		 SEARCH_FIND,info->s->state.key_root[def->key]))
   {

myisam/mi_update.c

@@ -111,6 +111,10 @@ int mi_update(register MI_INFO *info, const byte *oldrec, byte *newrec)
       {
 	uint new_length=_mi_make_key(info,i,new_key,newrec,pos);
 	uint old_length=_mi_make_key(info,i,old_key,oldrec,pos);
+
+        /* The above changed info->lastkey2. Inform mi_rnext_same(). */
+        info->update&= ~HA_STATE_RNEXT_SAME;
+
 	if (new_length != old_length ||
 	    memcmp((byte*) old_key,(byte*) new_key,new_length))
 	{

myisam/mi_write.c

@@ -132,6 +132,10 @@ int mi_write(MI_INFO *info, byte *record)
           goto err;
         }
       }
+
+      /* The above changed info->lastkey2. Inform mi_rnext_same(). */
+      info->update&= ~HA_STATE_RNEXT_SAME;
+
       if (local_lock_tree)
         rw_unlock(&share->key_root_lock[i]);
     }

mysql-test/r/myisam.result

@@ -729,6 +729,24 @@ select * from t1 where bob is null and cip=1;
 cip	time	score	bob
 1	00:01:00	0	NULL
 drop table t1;
+create table t1 (
+id1 int not null auto_increment,
+id2 int not null default '0',
+t text not null,
+primary key  (id1),
+key x (id2, t(32))
+) engine=myisam;
+insert into t1 (id2, t) values
+(10, 'abc'), (10, 'abc'), (10, 'abc'),
+(20, 'abc'), (20, 'abc'), (20, 'def'),
+(10, 'abc'), (10, 'abc');
+select count(*)   from t1 where id2 = 10;
+count(*)
+5
+select count(id1) from t1 where id2 = 10;
+count(id1)
+5
+drop table t1;
 set storage_engine=MyISAM;
 drop table if exists t1,t2,t3;
 --- Testing varchar ---

mysql-test/t/myisam.test

@@ -678,6 +678,25 @@ select * from t1 where bob is null and cip=1;
 create index bug on t1 (bob(22), cip, time);
 select * from t1 where bob is null and cip=1;
 drop table t1;
+
+#
+# Bug#14980 - COUNT(*) incorrect on MyISAM table with certain INDEX
+#
+create table t1 (
+  id1 int not null auto_increment,
+  id2 int not null default '0',
+  t text not null,
+  primary key  (id1),
+  key x (id2, t(32))
+) engine=myisam;
+insert into t1 (id2, t) values
+(10, 'abc'), (10, 'abc'), (10, 'abc'),
+(20, 'abc'), (20, 'abc'), (20, 'def'),
+(10, 'abc'), (10, 'abc');
+select count(*)   from t1 where id2 = 10;
+select count(id1) from t1 where id2 = 10;
+drop table t1;
+
 # End of 4.1 tests
 
 #