updated for version 7.3.108
Problem:    Useless check for NULL when calling vim_free().
Solution:   Remove the check. (Dominique Pelle)
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 3678083..3b2557e 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -5412,7 +5412,7 @@
     vir_T	*virp;
     int		force;
 {
-    if (old_sub != NULL && force)
+    if (force)
 	vim_free(old_sub);
     if (force || old_sub == NULL)
 	old_sub = viminfo_readstring(virp, 1, TRUE);