gnu: reptry: Fix build.

* gnu/packages/patches/reptyr-fix-gcc-7.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add new patch.
* gnu/packages/screen.scm (reptyr): Use patch.

gnu/local.mk

@@ -946,6 +946,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/readline-link-ncurses.patch		\
   %D%/packages/patches/readline-6.2-CVE-2014-2524.patch		\
   %D%/packages/patches/readline-7.0-mingw.patch			\
+  %D%/packages/patches/reptyr-fix-gcc-7.patch			\
   %D%/packages/patches/ripperx-missing-file.patch		\
   %D%/packages/patches/rpcbind-CVE-2017-8779.patch		\
   %D%/packages/patches/rpm-CVE-2014-8118.patch			\

gnu/packages/patches/reptyr-fix-gcc-7.patch

@@ -0,0 +1,38 @@
+This patch allows reptyr to build with gcc 7. It is taken from reptyr mainline patches
+fa0d63f and b45fd92.
+
+https://github.com/nelhage/reptyr/commit/fa0d63ff8c488be15976e5353580b565e85586a1
+https://github.com/nelhage/reptyr/commit/b45fd9238958fcf2d8f3d6fc23e6d491febea2ac
+
+Patch by Nelson Elhage <nelhage@nelhage.com>.
+
+diff --git a/attach.c b/attach.c
+index bd8ef8c..8d9cbf8 100644
+--- a/attach.c
++++ b/attach.c
+@@ -389,8 +389,11 @@ int setup_steal_socket(struct steal_pty_state *steal) {
+         return errno;
+ 
+     steal->addr_un.sun_family = AF_UNIX;
+-    snprintf(steal->addr_un.sun_path, sizeof(steal->addr_un.sun_path),
+-             "%s/reptyr.sock", steal->tmpdir);
++    if (snprintf(steal->addr_un.sun_path, sizeof(steal->addr_un.sun_path),
++                 "%s/reptyr.sock", steal->tmpdir) >= sizeof(steal->addr_un.sun_path)) {
++        error("tmpdir path too long!");
++        return ENAMETOOLONG;
++    }
+ 
+     if ((steal->sockfd = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0)
+         return errno;
+diff --git a/platform/linux/linux.h b/platform/linux/linux.h
+index 9e6b78a..3ec5a99 100644
+--- a/platform/linux/linux.h
++++ b/platform/linux/linux.h
+@@ -40,6 +40,7 @@
+ #include <sys/ptrace.h>
+ #include <asm/ptrace.h>
+ #include <sys/types.h>
++#include <sys/sysmacros.h>
+ #include <sys/user.h>
+ #include <unistd.h>
+ #include <stdlib.h>

gnu/packages/screen.scm

@@ -4,6 +4,7 @@
 ;;; Copyright © 2015 Eric Bavier <bavier@member.fsf.org>
 ;;; Copyright © 2016, 2017 Efraim Flashner <efraim@flashner.co.il>
 ;;; Copyright © 2016 Alex Griffin <a@ajgrf.com>
+;;; Copyright © 2017 Mathieu Othacehe <m.othacehe@gmail.com>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -155,6 +156,8 @@ window manager as well as the Tmux terminal multiplexer.")
        (method url-fetch)
        (uri (string-append "https://github.com/nelhage/reptyr/archive"
                            "/reptyr-" version ".tar.gz"))
+       ;; XXX: To be removed on next reptyr release.
+       (patches (search-patches "reptyr-fix-gcc-7.patch"))
        (sha256
         (base32
          "07pfl0rkgm8m3f3jy8r9l2yvnhf8lgllpsk3mh57mhzdxq8fagf7"))))