patch 7.4.1476
Problem:    Function arguments marked as unused while they are not.
Solution:   Remove UNUSED. (Yegappan Lakshmanan)
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 9900c1b..4aa7f5d 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -9262,7 +9262,7 @@
  * ":undo".
  */
     static void
-ex_undo(exarg_T *eap UNUSED)
+ex_undo(exarg_T *eap)
 {
     if (eap->addr_count == 1)	    /* :undo 123 */
 	undo_time(eap->line2, FALSE, FALSE, TRUE);
@@ -9759,7 +9759,7 @@
 #if ((defined(FEAT_SESSION) || defined(FEAT_EVAL)) && defined(vim_mkdir)) \
 	|| defined(PROTO)
     int
-vim_mkdir_emsg(char_u *name, int prot UNUSED)
+vim_mkdir_emsg(char_u *name, int prot)
 {
     if (vim_mkdir(name, prot) != 0)
     {