Bug#37284 Crash in Field_string::type()

The bug is repeatable with latest(1.0.1) InnoDB plugin on Linux, Win,
If MySQL is compiled with valgrind there are errors about
using of uninitialized variable(orig_table).
The fix is to set field->orig_table correct value.

mysql-test/r/innodb_mysql.result

@@ -1261,4 +1261,10 @@ a	b	c
 5	1	1
 4	1	1
 DROP TABLE t1;
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (a char(50)) ENGINE=InnoDB;
+CREATE INDEX i1 on t1 (a(3));
+SELECT * FROM t1 WHERE a = 'abcde';
+a
+DROP TABLE t1;
 End of 5.0 tests

mysql-test/t/innodb_mysql.test

@@ -1014,4 +1014,15 @@ SELECT a, b, c FROM t1 WHERE b = 1 ORDER BY a DESC LIMIT 5;
 
 DROP TABLE t1;
 
+# 
+# Bug#37284 Crash in Field_string::type() 
+# 
+--disable_warnings 
+DROP TABLE IF EXISTS t1; 
+--enable_warnings 
+CREATE TABLE t1 (a char(50)) ENGINE=InnoDB; 
+CREATE INDEX i1 on t1 (a(3)); 
+SELECT * FROM t1 WHERE a = 'abcde'; 
+DROP TABLE t1;
+
 --echo End of 5.0 tests

sql/sql_base.cc

@@ -2102,7 +2102,10 @@ bool reopen_table(TABLE *table,bool locked)
   for (key=0 ; key < table->s->keys ; key++)
   {
     for (part=0 ; part < table->key_info[key].usable_key_parts ; part++)
+    {
       table->key_info[key].key_part[part].field->table= table;
+      table->key_info[key].key_part[part].field->orig_table= table;
+    }
   }
   if (table->triggers)
     table->triggers->set_table(table);