Fixed LP bug #663818.

After the patch for bug 663840 had been applied the test case for
bug 663818 triggered the assert introduced by this patch.
It happened because the the patch turned out to be incomplete:
the space needed for a key entry must be taken into account
for the record written into the buffer, and, for the next record
as well, when figuring out whether the record being written is
the last for the buffer or not. 

mysql-test/r/innodb_mysql.result

@@ -2390,3 +2390,59 @@ SECOND(c)-@bug47453
 0
 DROP TABLE t1, t2;
 End of 5.1 tests
+#
+# Bug #663818: wrong result when BNLH is used 
+#
+CREATE TABLE t1(pk int NOT NULL PRIMARY KEY) ENGINE=InnoDB;
+INSERT INTO t1 VALUES 
+(1), (2), (11), (12), (13), (14),
+(15), (16), (17), (18), (19);
+CREATE TABLE t2(pk int NOT NULL PRIMARY KEY) ENGINE=InnoDB;
+INSERT INTO t2 VALUES 
+(1), (10), (11), (12), (13), (14),
+(15), (16), (17), (18), (19), (20), (21);
+SET SESSION join_buffer_size=10000;
+SET SESSION join_cache_level=3;
+EXPLAIN
+SELECT t1.pk FROM t1,t2 
+WHERE t1.pk = t2.pk AND t2.pk <> 8;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	11	Using where; Using index
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	Using index; Using join buffer (flat, BNLH join)
+SELECT t1.pk FROM t1,t2 
+WHERE t1.pk = t2.pk AND t2.pk <> 8;
+pk
+1
+11
+12
+13
+14
+15
+16
+17
+18
+19
+SET SESSION join_cache_level=1;
+EXPLAIN
+SELECT t1.pk FROM t1,t2 
+WHERE t1.pk = t2.pk AND t2.pk <> 8;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	PRIMARY	PRIMARY	4	NULL	11	Using where; Using index
+1	SIMPLE	t2	eq_ref	PRIMARY	PRIMARY	4	test.t1.pk	1	Using index
+SELECT t1.pk FROM t1,t2 
+WHERE t1.pk = t2.pk AND t2.pk <> 8;
+pk
+1
+11
+12
+13
+14
+15
+16
+17
+18
+19
+DROP TABLE t1,t2;
+SET SESSION join_cache_level=DEFAULT;
+SET SESSION join_buffer_size=DEFAULT;
+End of 5.3 tests

mysql-test/t/innodb_mysql.test

@@ -634,3 +634,39 @@ SELECT SECOND(c)-@bug47453 FROM t1 JOIN t2 ON d=a;
 DROP TABLE t1, t2;
 
 --echo End of 5.1 tests
+
+--echo #
+--echo # Bug #663818: wrong result when BNLH is used 
+--echo #
+
+CREATE TABLE t1(pk int NOT NULL PRIMARY KEY) ENGINE=InnoDB;
+INSERT INTO t1 VALUES 
+  (1), (2), (11), (12), (13), (14),
+  (15), (16), (17), (18), (19);
+CREATE TABLE t2(pk int NOT NULL PRIMARY KEY) ENGINE=InnoDB;
+INSERT INTO t2 VALUES 
+  (1), (10), (11), (12), (13), (14),
+  (15), (16), (17), (18), (19), (20), (21);
+
+SET SESSION join_buffer_size=10000;
+
+SET SESSION join_cache_level=3;
+EXPLAIN
+SELECT t1.pk FROM t1,t2 
+  WHERE t1.pk = t2.pk AND t2.pk <> 8;
+SELECT t1.pk FROM t1,t2 
+  WHERE t1.pk = t2.pk AND t2.pk <> 8;
+
+SET SESSION join_cache_level=1;
+EXPLAIN
+SELECT t1.pk FROM t1,t2 
+  WHERE t1.pk = t2.pk AND t2.pk <> 8;
+SELECT t1.pk FROM t1,t2 
+  WHERE t1.pk = t2.pk AND t2.pk <> 8;
+
+DROP TABLE t1,t2;
+
+SET SESSION join_cache_level=DEFAULT;
+SET SESSION join_buffer_size=DEFAULT;
+
+--echo End of 5.3 tests

sql/sql_join_cache.cc

@@ -1161,10 +1161,11 @@ uint JOIN_CACHE::write_record_data(uchar * link, bool *is_full)
   uchar *cp= pos;
   uchar *init_pos= cp;
   uchar *rec_len_ptr= 0;
+  uint key_extra= extra_key_length();
  
   records++;  /* Increment the counter of records in the cache */
 
-  len= pack_length + extra_key_length();
+  len= pack_length + key_extra;
 
   /* Make an adjustment for the size of the auxiliary buffer if there is any */
   uint incr= aux_buffer_incr(records);
@@ -1204,7 +1205,7 @@ uint JOIN_CACHE::write_record_data(uchar * link, bool *is_full)
     This function is called only in the case when there is enough space left in
     the cache to store at least non-blob parts of the current record.
   */
-  last_record= (len+pack_length_with_blob_ptrs) > rem_space();
+  last_record= (len+pack_length_with_blob_ptrs+key_extra) > rem_space();
   
   /* 
     Save the position for the length of the record in the cache if it's needed.

sql/sql_select.h

@@ -1282,7 +1282,7 @@ protected:
     Calculate how much space is taken by allocation of the key
     entry for a record in the join buffer
   */
-  virtual uint extra_key_length() { return key_entry_length; }
+  uint extra_key_length() { return key_entry_length; }
 
   /* 
     Skip record from a hashed join buffer if its match flag