Proposed fix for #751

Fields in key_expr (mysql_ha_read) wasn't linked to tables.
Hmm. How did it work at all?

mysql-test/r/alias.result

@@ -70,3 +70,4 @@ INSERT INTO t1 VALUES ('40004712','000001','0020',0);
 UPDATE t1 SET t1.xstatus_vor = Greatest(t1.xstatus_vor,1) WHERE t1.aufnr =
 "40004712" AND t1.plnfl = "000001" AND t1.vornr > "0010" ORDER BY t1.vornr
 ASC LIMIT 1;
+drop table t1;

mysql-test/r/handler.result

@@ -146,3 +146,9 @@ alter table t1 type=MyISAM;
 handler t2 read first;
 Unknown table 't2' in HANDLER
 drop table t1;
+create table t1(a int, index(a));
+insert into t1 values (1), (2), (3);
+handler t1 open;
+handler t1 read a=(W);
+Unknown column 'W' in 'field list'
+drop table t1;

mysql-test/t/alias.test

@@ -81,3 +81,5 @@ INSERT INTO t1 VALUES ('40004712','000001','0020',0);
 UPDATE t1 SET t1.xstatus_vor = Greatest(t1.xstatus_vor,1) WHERE t1.aufnr =
 "40004712" AND t1.plnfl = "000001" AND t1.vornr > "0010" ORDER BY t1.vornr
 ASC LIMIT 1;
+
+drop table t1;

mysql-test/t/handler.test

@@ -80,3 +80,13 @@ alter table t1 type=MyISAM;
 handler t2 read first;
 drop table t1;
 
+#
+#test for #751
+#
+create table t1(a int, index(a));
+insert into t1 values (1), (2), (3);
+handler t1 open;
+--error 1054
+handler t1 read a=(W);
+drop table t1;
+

sql/sql_handler.cc

@@ -193,6 +193,8 @@ int mysql_ha_read(THD *thd, TABLE_LIST *tables,
       Item *item;
       for (key_len=0 ; (item=it_ke++) ; key_part++)
       {
+	if (item->fix_fields(thd, tables))
+	    return -1;
 	item->save_in_field(key_part->field, 1);
 	key_len+=key_part->store_length;
       }