gnu: emacs-exwm: Fix fullscreen issue.

* gnu/packages/patches/emacs-exwm-fix-fullscreen-issue.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/emacs.scm (emacs-exwm)[sources]: Add
emacs-exwm-fix-fullscreen-issue.patch to patches.

gnu/local.mk

@@ -651,6 +651,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/elogind-glibc-2.27.patch			\
   %D%/packages/patches/einstein-build.patch			\
   %D%/packages/patches/emacs-exec-path.patch			\
+  %D%/packages/patches/emacs-exwm-fix-fullscreen-issue.patch	\
   %D%/packages/patches/emacs-fix-scheme-indent-function.patch	\
   %D%/packages/patches/emacs-json-reformat-fix-tests.patch	\
   %D%/packages/patches/emacs-highlight-stages-add-gexp.patch	\

gnu/packages/emacs.scm

@@ -6290,7 +6290,8 @@ It should enable you to implement low-level X11 applications.")
                                   version ".tar"))
               (sha256
                (base32
-                "11xd2w4h3zdwkdxypvmcz8s7q72cn76lfr9js77jbizyj6b04lr0"))))
+                "11xd2w4h3zdwkdxypvmcz8s7q72cn76lfr9js77jbizyj6b04lr0"))
+              (patches (search-patches "emacs-exwm-fix-fullscreen-issue.patch"))))
     (build-system emacs-build-system)
     (propagated-inputs
      `(("emacs-xelb" ,emacs-xelb)))

gnu/packages/patches/emacs-exwm-fix-fullscreen-issue.patch

@@ -0,0 +1,27 @@
+From 13a14579cc1bb772735f895dd5b4b90c6812f3ee Mon Sep 17 00:00:00 2001
+From: Chris Feng <chris.w.feng@gmail.com>
+Date: Sun, 29 Jul 2018 00:00:00 +0000
+Subject: [PATCH] Fix issues with destroying full screen X windows
+
+* exwm-manage.el (exwm-manage--unmanage-window): Set the Emacs window
+of an full screen X window as non-dedicated before killing its buffer
+so as not to cause other side effects.
+---
+ exwm-manage.el | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+diff --git a/exwm-manage.el b/exwm-manage.el
+index a0a9e05..349157f 100644
+--- a/exwm-manage.el
++++ b/exwm-manage.el
+@@ -392,6 +392,10 @@ manager is shutting down."
+                                :window window :parent exwm--root :x 0 :y 0))
+             (xcb:+request exwm--connection
+                 (make-instance 'xcb:DestroyWindow :window container))))
++        (when (exwm-layout--fullscreen-p)
++          (let ((window (get-buffer-window)))
++            (when window
++              (set-window-dedicated-p window nil))))
+         (exwm-manage--set-client-list)
+         (xcb:flush exwm--connection))
+       (let ((kill-buffer-func