Merge dl145s.mysql.com:/users/mhansson/mysql/push/bug23856/my50-bug23856

into  dl145s.mysql.com:/users/mhansson/mysql/push/bug23856/my51-bug23856

sql/field.h

@@ -1175,7 +1175,7 @@ class Field_varstring :public Field_longstr {
     The maximum space available in a Field_varstring, in bytes. See
     length_bytes.
   */
-  static const int MAX_SIZE= UINT_MAX16;
+  static const uint MAX_SIZE= UINT_MAX16;
   /* Store number of bytes used to store length (1 or 2) */
   uint32 length_bytes;
   Field_varstring(char *ptr_arg,