A fix for bit type.

pack_length_in_rec() func has been introduced.

sql/field.h

@@ -123,6 +123,7 @@ class Field
   }
   virtual bool eq_def(Field *field);
   virtual uint32 pack_length() const { return (uint32) field_length; }
+  virtual uint32 pack_length_in_rec() const { return pack_length(); }
   virtual void reset(void) { bzero(ptr,pack_length()); }
   virtual void reset_fields() {}
   virtual void set_default()
@@ -1237,6 +1238,7 @@ class Field_bit :public Field {
   { get_key_image(buff, length, itRAW); }
   uint32 pack_length() const 
   { return (uint32) field_length + (bit_len > 0); }
+  uint32 pack_length_in_rec() const { return field_length; }
   void sql_type(String &str) const;
   field_cast_enum field_cast_type() { return FIELD_CAST_BIT; }
   char *pack(char *to, const char *from, uint max_length=~(uint) 0);

sql/ha_myisam.cc

@@ -1467,7 +1467,7 @@ int ha_myisam::create(const char *name, register TABLE *table_arg,
 	  fieldpos <= minpos)
       {
 	/* skip null fields */
-	if (!(temp_length= (*field)->pack_length()))
+	if (!(temp_length= (*field)->pack_length_in_rec()))
 	  continue;				/* Skip null-fields */
 	if (! found || fieldpos < minpos ||
 	    (fieldpos == minpos && temp_length < length))