Fix reporting of type for unique key on VARCHAR field. (Bug #11227)

mysql-test/r/key.result

@@ -354,3 +354,28 @@ t1	CREATE TABLE `t1` (
   KEY `a` (`a`,`b`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
+create table t1 (a int not null primary key, b varchar(20) not null unique);
+desc t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO	PRI		
+b	varchar(20)	NO	UNI		
+drop table t1;
+create table t1 (a int not null primary key, b int not null unique);
+desc t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO	PRI		
+b	int(11)	NO	UNI		
+drop table t1;
+create table t1 (a int not null primary key, b varchar(20) not null, unique (b(10)));
+desc t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO	PRI		
+b	varchar(20)	NO	UNI		
+drop table t1;
+create table t1 (a int not null primary key, b varchar(20) not null, c varchar(20) not null, unique(b(10),c(10)));
+desc t1;
+Field	Type	Null	Key	Default	Extra
+a	int(11)	NO	PRI		
+b	varchar(20)	NO	MUL		
+c	varchar(20)	NO			
+drop table t1;

mysql-test/t/key.test

@@ -337,3 +337,19 @@ show create table t1;
 alter table t1 modify a varchar(20);
 show create table t1;
 drop table t1;
+
+#
+# Bug #11227: Incorrectly reporting 'MUL' vs. 'UNI' on varchar
+#
+create table t1 (a int not null primary key, b varchar(20) not null unique);
+desc t1;
+drop table t1;
+create table t1 (a int not null primary key, b int not null unique);
+desc t1;
+drop table t1;
+create table t1 (a int not null primary key, b varchar(20) not null, unique (b(10)));
+desc t1;
+drop table t1;
+create table t1 (a int not null primary key, b varchar(20) not null, c varchar(20) not null, unique(b(10),c(10)));
+desc t1;
+drop table t1;

sql/table.cc

@@ -701,10 +701,9 @@ int openfrm(THD *thd, const char *name, const char *alias, uint db_stat,
             key_part->key_part_flag|= HA_BIT_PART;
 
 	  if (i == 0 && key != primary_key)
-	    field->flags |=
-	      ((keyinfo->flags & HA_NOSAME) &&
-	       field->key_length() ==
-	       keyinfo->key_length ? UNIQUE_KEY_FLAG : MULTIPLE_KEY_FLAG);
+	    field->flags |= ((keyinfo->flags & HA_NOSAME) &&
+                             (keyinfo->key_parts == 1)) ?
+                            UNIQUE_KEY_FLAG : MULTIPLE_KEY_FLAG;
 	  if (i == 0)
 	    field->key_start.set_bit(key);
 	  if (field->key_length() == key_part->length &&