gnu: evilwm: Add patch for lost-focus bug.

* gnu/packages/patches/evilwm-lost-focus-bug.patch: New patch.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/wm.scm (evilwm)[source]: Use it.

gnu-system.am

@@ -438,6 +438,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/elfutils-tests-ptrace.patch		\
   gnu/packages/patches/emacs-exec-path.patch			\
   gnu/packages/patches/eudev-rules-directory.patch		\
+  gnu/packages/patches/evilwm-lost-focus-bug.patch		\
   gnu/packages/patches/expat-CVE-2015-1283.patch		\
   gnu/packages/patches/fastcap-mulGlobal.patch			\
   gnu/packages/patches/fastcap-mulSetup.patch			\

gnu/packages/patches/evilwm-lost-focus-bug.patch

+evilwm may sometimes lose focus after closing a window.  This means that
+evilwm stops responding to keyboard shortcuts, and if no other window is open
+which the mouse can be moved over to regain focus evilwm becomes unusable and
+has to be restarted.
+
+Patch derived from discussion at
+https://wiki.archlinux.org/index.php/Evilwm#Lost_focus_bug_fix
+
+--- evilwm-1.1.1/client.c
++++ evilwm-1.1.1/client.c
+@@ -172,6 +172,7 @@
+ 	 *  _NET_WM_STATE) */
+ 	if (c->remove) {
+ 		LOG_DEBUG("setting WithdrawnState\n");
++		XSetInputFocus(dpy, PointerRoot, RevertToPointerRoot, CurrentTime);
+ 		set_wm_state(c, WithdrawnState);
+ 		ewmh_withdraw_client(c);
+ 	} else {

gnu/packages/wm.scm

@@ -22,6 +22,7 @@
 (define-module (gnu packages wm)
   #:use-module (guix licenses)
   #:use-module (guix packages)
+  #:use-module (gnu packages)
   #:use-module (gnu packages linux)
   #:use-module (guix build-system gnu)
   #:use-module (guix build-system haskell)
@@ -268,7 +269,8 @@ (define-public evilwm
                            version ".tar.gz"))
        (sha256
         (base32
-         "0ak0yajzk3v4dg5wmaghv6acf7v02a4iw8qxmq5yw5ard8lrqn3r"))))
+         "0ak0yajzk3v4dg5wmaghv6acf7v02a4iw8qxmq5yw5ard8lrqn3r"))
+       (patches (map search-patch '("evilwm-lost-focus-bug.patch")))))
     (build-system gnu-build-system)
     (inputs
      `(("libx11" ,libx11)