This is internal patch implementing mutt's issue:
http://dev.mutt.org/trac/ticket/3392

This link is no longer available as Mutt's issue ticketing system moved
since the time of creating this issue from http://dev.mutt.org/hg/mutt/
to https://gitlab.com/muttmua/mutt

However, there is still at least some external discussion found at:
https://www.mail-archive.com/mutt-users@mutt.org/msg41591.html

--- mutt-1.8.2/pager.c.~1~	2017-04-19 02:05:35.000000000 +0300
+++ mutt-1.8.2/pager.c	2017-04-19 17:03:14.288263039 +0300
@@ -1632,6 +1632,8 @@
   }
   unlink (fname);
 
+  clearok(stdscr,TRUE);
+
   /* Initialize variables */
 
   if (IsHeader (extra) && !extra->hdr->read)