Fix for BUG#9439:

Changed type of "Sub_part" column in SHOW KEYS from TINYINT to SMALLINT (as MAX_KEY_LENGTH=1024)
(this is the final cset with proper tests)

mysql-test/r/show_check.result

@@ -477,3 +477,24 @@ t1	CREATE TABLE `t1` (
   KEY `i` TYPE BTREE (`i`)
 ) ENGINE=HEAP DEFAULT CHARSET=latin1
 DROP TABLE t1;
+CREATE TABLE t1(
+field1 text NOT NULL,
+PRIMARY KEY(field1(1000))
+);
+show index from t1;
+Catalog	Database	Table	Table_alias	Column	Column_alias	Type	Length	Max length	Is_null	Flags	Decimals	Charsetnr
+def					Table	253	64	2	N	129	31	63
+def					Non_unique	1	1	1	N	32929	0	63
+def					Key_name	253	64	7	N	129	31	63
+def					Seq_in_index	1	2	1	N	32929	0	63
+def					Column_name	253	64	6	N	129	31	63
+def					Collation	253	1	1	Y	128	31	63
+def					Cardinality	8	21	1	Y	32896	0	63
+def					Sub_part	2	3	4	Y	32928	0	63
+def					Packed	253	10	0	Y	128	31	63
+def					Null	253	3	0	N	129	31	63
+def					Index_type	253	16	5	N	129	31	63
+def					Comment	253	255	0	N	129	31	63
+Table	Non_unique	Key_name	Seq_in_index	Column_name	Collation	Cardinality	Sub_part	Packed	Null	Index_type	Comment
+t1	0	PRIMARY	1	field1	A	0	1000	NULL		BTREE	
+drop table t1;

mysql-test/t/show_check.test

@@ -357,3 +357,14 @@ SHOW CREATE TABLE t1;
 ALTER TABLE t1 ENGINE=MEMORY;
 SHOW CREATE TABLE t1;
 DROP TABLE t1;
+
+# Test for BUG#9439 "Reporting wrong datatype for sub_part on show index"
+CREATE TABLE t1(
+  field1 text NOT NULL,
+  PRIMARY KEY(field1(1000))
+);
+--enable_metadata
+show index from t1;
+--disable_metadata
+drop table t1;
+

sql/sql_show.cc

@@ -980,7 +980,7 @@ mysqld_show_keys(THD *thd, TABLE_LIST *table_list)
   field_list.push_back(item=new Item_int("Cardinality",0,21));
   item->maybe_null=1;
   field_list.push_back(item=new Item_return_int("Sub_part",3,
-						MYSQL_TYPE_TINY));
+						MYSQL_TYPE_SHORT));
   item->maybe_null=1;
   field_list.push_back(item=new Item_empty_string("Packed",10));
   item->maybe_null=1;
@@ -1025,7 +1025,7 @@ mysqld_show_keys(THD *thd, TABLE_LIST *table_list)
       /* Check if we have a key part that only uses part of the field */
       if (!(key_info->flags & HA_FULLTEXT) && (!key_part->field ||
           key_part->length != table->field[key_part->fieldnr-1]->key_length()))
-        protocol->store_tiny((longlong) key_part->length / 
+        protocol->store_short((longlong) key_part->length / 
                              key_part->field->charset()->mbmaxlen);
       else
         protocol->store_null();