gentoo-overlay/app-misc/screen/files/4.0.2-nonblock.patch

--- screen.c.orig	2006-04-02 17:05:28.000000000 +0200
+++ screen.c	2006-04-02 17:05:39.000000000 +0200
@@ -1197,7 +1197,7 @@ char **av;
   if (!detached)
     {
       /* reopen tty. must do this, because fd 0 may be RDONLY */
-      if ((n = secopen(attach_tty, O_RDWR, 0)) < 0)
+      if ((n = secopen(attach_tty, O_RDWR | O_NONBLOCK, 0)) < 0)
 	Panic(0, "Cannot reopen '%s' - please check.", attach_tty);
     }
   else