Apply by doing:
       If the unpatched screen is already installed:
       cd /usr/ports/misc/screen
       make deinstall

       Otherwise start here:
       cd /usr/ports
       patch -p0 < 017_screen.patch
       cd misc/screen
       make clean
       make install

Index: misc/screen/Makefile
===================================================================
RCS file: /cvs/ports/misc/screen/Makefile,v
retrieving revision 1.19
diff -u -r1.19 Makefile
--- misc/screen/Makefile        2000/03/24 22:11:50     1.19
+++ misc/screen/Makefile        2000/07/03 18:22:59
@@ -1,6 +1,7 @@
-# $OpenBSD: Makefile,v 1.19 2000/03/24 22:11:50 espie Exp $
+# $OpenBSD: Makefile,v 1.22 2000/06/23 18:59:39 brad Exp $

DISTNAME=      screen-3.9.5
+PKGNAME=       screen-3.9.5p1
CATEGORIES=    misc
NEED_VERSION=  1.218
MASTER_SITES=  ftp://ftp.uni-erlangen.de/pub/utilities/screen/ \
@@ -20,6 +21,8 @@
FAKE=          Yes

post-install:
+       @rm -f ${PREFIX}/bin/screen
+       @cd ${PREFIX}/bin; ln -sf screen-3.9.5 screen
       ${INSTALL_DATA_DIR} ${PREFIX}/lib/screen
       ${INSTALL_DATA} ${WRKSRC}/etc/etcscreenrc ${PREFIX}/lib/screen/screenrc
       ${INSTALL_DATA} ${WRKSRC}/terminfo/screencap ${PREFIX}/lib/screen
Index: misc/screen/pkg/PLIST
===================================================================
RCS file: /cvs/ports/misc/screen/pkg/PLIST,v
retrieving revision 1.7
diff -u -r1.7 PLIST
--- misc/screen/pkg/PLIST       2000/05/10 21:54:47     1.7
+++ misc/screen/pkg/PLIST       2000/07/03 18:23:00
@@ -1,6 +1,6 @@
+@comment $OpenBSD: PLIST,v 1.10 2000/06/23 18:59:40 brad Exp $
+bin/screen
bin/screen-3.9.5
-@exec ln -sf %B%f %B/screen
-@unexec rm -f %B/screen
man/man1/screen.1
@unexec install-info --delete %D/info/screen.info %D/info/dir
info/screen.info