Merge with 4.0.9

BitKeeper/etc/ignore:
  auto-union
client/mysqltest.c:
  Auto merged
configure.in:
  Auto merged
BitKeeper/deleted/.del-mutex.h~d3ae7a2977a68137:
  Auto merged
BitKeeper/deleted/.del-mutex.m4~a13383cde18a64e1:
  Auto merged
innobase/btr/btr0cur.c:
  Auto merged
innobase/btr/btr0pcur.c:
  Auto merged
innobase/log/log0log.c:
  Auto merged
innobase/srv/srv0srv.c:
  Auto merged
innobase/trx/trx0trx.c:
  Auto merged
myisam/mi_create.c:
  Auto merged
myisam/mi_unique.c:
  Auto merged
myisam/myisamchk.c:
  Auto merged
mysql-test/mysql-test-run.sh:
  Auto merged
mysql-test/r/group_by.result:
  Auto merged
mysql-test/r/merge.result:
  Auto merged
mysql-test/r/null.result:
  Auto merged
mysql-test/t/group_by.test:
  Auto merged
mysql-test/t/merge.test:
  Auto merged
mysql-test/t/null.test:
  Auto merged
scripts/mysql_fix_privilege_tables.sh:
  Auto merged
sql/field_conv.cc:
  Auto merged
sql/ha_myisammrg.cc:
  Auto merged
sql/mysqld.cc:
  Auto merged
sql/net_serv.cc:
  Auto merged
sql/opt_sum.cc:
  Auto merged
sql/protocol.cc:
  Auto merged
sql/sql_db.cc:
  Auto merged
sql/sql_load.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
strings/Makefile.am:
  Auto merged
libmysql/Makefile.shared:
  merge
libmysql/libmysql.def:
  merge
sql/ha_innodb.cc:
  merge
sql/item_cmpfunc.cc:
  merge
sql/log_event.cc:
  merge
sql/sql_handler.cc:
  merge

1 files changed, 10 insertions, 1 deletions

diff --git a/myisam/mi_unique.c b/myisam/mi_unique.c
index 682f946eba7..3eb25aefe0e 100644
--- a/myisam/mi_unique.c
+++ b/myisam/mi_unique.c
@@ -24,7 +24,7 @@ my_bool mi_check_unique(MI_INFO *info, MI_UNIQUEDEF *def, byte *record,
 {
   my_off_t lastpos=info->lastpos;
   MI_KEYDEF *key= &info->s->keyinfo[def->key];
-  uchar *key_buff=info->lastkey+info->s->base.max_key_length;
+  uchar *key_buff=info->lastkey2;
   DBUG_ENTER("mi_check_unique");
 
   mi_unique_store(record+key->seg->start, unique_hash);
@@ -80,7 +80,16 @@ ha_checksum mi_unique_hash(MI_UNIQUEDEF *def, const byte *record)
     if (keyseg->null_bit)
     {
       if (record[keyseg->null_pos] & keyseg->null_bit)
+      {
+	/*
+	  Change crc in a way different from an empty string or 0.
+	  (This is an optimisation;  The code will work even if this isn't
+	  done)
+	*/
+	crc=((crc << 8) + 511+
+	     (crc >> (8*sizeof(ha_checksum)-8)));
 	continue;
+      }
     }
     pos= record+keyseg->start;
     if (keyseg->flag & HA_VAR_LENGTH)