patch 8.0.0034
Problem:    No completion for ":messages".
Solution:   Complete "clear" argument. (Hirohito Higashi)
diff --git a/src/proto/ex_docmd.pro b/src/proto/ex_docmd.pro
index b92ce80..11a3f71 100644
--- a/src/proto/ex_docmd.pro
+++ b/src/proto/ex_docmd.pro
@@ -61,4 +61,5 @@
 int put_line(FILE *fd, char *s);
 void dialog_msg(char_u *buff, char *format, char_u *fname);
 char_u *get_behave_arg(expand_T *xp, int idx);
+char_u *get_messages_arg(expand_T *xp, int idx);
 /* vim: set ft=c : */