gnu: slim: Display login message.

* gnu/packages/patches/slim-login.patch: New patch.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/display-managers.scm (slim)[source]: Use it.

gnu/local.mk

@@ -830,6 +830,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/slim-config.patch			\
   %D%/packages/patches/slim-sigusr1.patch			\
   %D%/packages/patches/slim-reset.patch				\
+  %D%/packages/patches/slim-login.patch				\
   %D%/packages/patches/slock-CVE-2016-6866.patch		\
   %D%/packages/patches/slurm-configure-remove-nonfree-contribs.patch \
   %D%/packages/patches/soprano-find-clucene.patch		\

gnu/packages/display-managers.scm

@@ -200,6 +200,7 @@ create smooth, animated user interfaces.")
 	      (base32 "1pqhk22jb4aja4hkrm7rjgbgzjyh7i4zswdgf5nw862l2znzxpi1"))
              (patches (search-patches "slim-config.patch"
                                       "slim-reset.patch"
+                                      "slim-login.patch"
                                       "slim-session.patch"
                                       "slim-sigusr1.patch"))))
     (build-system cmake-build-system)

gnu/packages/patches/slim-login.patch

@@ -0,0 +1,35 @@
+Display configurable login message after successful authentication.
+
+Patch by E. Bavier
+
+--- slim-1.3.6/panel.cpp.orig	1969-12-31 18:00:00.000000000 -0600
++++ slim-1.3.6/panel.cpp	2016-10-17 17:00:07.259649063 -0500
+@@ -260,19 +260,19 @@
+ 
+ void Panel::ClosePanel() {
+ 	XUngrabKeyboard(Dpy, CurrentTime);
++	XClearWindow(Dpy, Root);
+ 	XUnmapWindow(Dpy, Win);
+ 	XDestroyWindow(Dpy, Win);
+ 	XFlush(Dpy);
+--- slim-1.3.6/cfg.cpp.orig	2016-10-17 17:08:06.767666139 -0500
++++ slim-1.3.6/cfg.cpp	2016-10-17 17:06:53.115663516 -0500
+@@ -52,6 +52,7 @@
+ 	options.insert(option("lockfile","/var/run/slim.lock"));
+ 	options.insert(option("logfile","/var/log/slim.log"));
+ 	options.insert(option("authfile","/var/run/slim.auth"));
++	options.insert(option("login_msg","Logging in..."));
+ 	options.insert(option("shutdown_msg","The system is halting..."));
+ 	options.insert(option("reboot_msg","The system is rebooting..."));
+ 	options.insert(option("sessiondir",""));
+--- slim-1.3.6/app.cpp.orig	2016-10-17 17:08:41.731667384 -0500
++++ slim-1.3.6/app.cpp	2016-10-17 17:07:48.415665486 -0500
+@@ -520,6 +520,8 @@
+ 	struct passwd *pw;
+ 	pid_t pid;
+ 
++	LoginPanel->Message((char*)cfg->getOption("login_msg").c_str());
++
+ #ifdef USE_PAM
+ 	try{
+ 		pam.open_session();