This patch fixes SLiM so it really waits for the X server to be ready
before attempting to connect to it.  Indeed, the X server notices that
its parent process has a handler for SIGUSR1, and consequently sends it
SIGUSR1 when it's ready to accept connections.

The problem was that SLiM doesn't pay attention to SIGUSR1.  So in practice,
if X starts slowly, then SLiM gets ECONNREFUSED a couple of time on
/tmp/.X11-unix/X0, then goes on trying to connect to localhost:6000,
where nobody answers; eventually, it times out and tries again on
/tmp/.X11-unix/X0, and finally it shows up on the screen.

Patch by L. Courtès.

--- slim-1.3.6/app.cpp	2014-02-05 15:27:20.000000000 +0100
+++ slim-1.3.6/app.cpp	2014-02-09 22:42:04.000000000 +0100
@@ -119,7 +119,9 @@ void CatchSignal(int sig) {
 	exit(ERR_EXIT);
 }
 
+static volatile int got_sigusr1 = 0;
 void User1Signal(int sig) {
+	got_sigusr1 = 1;
 	signal(sig, User1Signal);
 }
 
@@ -884,6 +886,7 @@ int App::WaitForServer() {
 	int	ncycles	 = 120;
 	int	cycles;
 
+	while (!got_sigusr1);
 	for(cycles = 0; cycles < ncycles; cycles++) {
 		if((Dpy = XOpenDisplay(DisplayName))) {
 			XSetIOErrorHandler(xioerror);
3d45'>refs</a><a class='active' href='/guix/log/gnu/services/spice.scm'>log</a><a href='/guix/tree/gnu/services/spice.scm?id=c5829570a8dd7699ede50199a06cb1cf966c3d45'>tree</a><a href='/guix/commit/gnu/services/spice.scm?id=c5829570a8dd7699ede50199a06cb1cf966c3d45'>commit</a><a href='/guix/diff/gnu/services/spice.scm?id=c5829570a8dd7699ede50199a06cb1cf966c3d45'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/services/spice.scm'>
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<tr><td><span title='2021-05-06 16:51:49 -0400'>2021-05-06</span></td><td><a href='/guix/commit/gnu/services/spice.scm?id=b39c4e18f28d39929a034a2350b316038044638e'>services: spice-vdagent: Clear the socket file prior to starting.</a><span class='msg-avail'>...<span class='msg-tooltip'>This fixes the following issue where spice-vdagent would fail to start if the
spice-vdagent-sock socket file already existed:

  spice-vdagentd: Fatal could not create the server socket
  /run/spice-vdagentd/spice-vdagent-sock: Error binding to address: Address
  already in use

The requirement is also modified to depend on dbus-system, a cue taken from
upstream's own systemd service file (see 'data/spice-vdagentd.service' in the
sources).

* gnu/services/spice.scm (spice-vdagent-activation): Delete procedure.
(spice-vdagent-shepherd-service): Fix indentation.
[requirement]: Replace udev by dbus-system.
[start]: Ensure the spice-vdagentd run-time directory exists and that the
spice-vdagent-sock socket file does *not* exist before forking the daemon.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-05-05 16:31:06 -0400'>2021-05-05</span></td><td><a href='/guix/commit/gnu/services/spice.scm?id=6b0704339dacaada2dd9a999395c2dffc1bd9af0'>services: Fix the spice-vdagent service.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/spice.scm (spice-vdagent-activation): Update runtime directory
from /var/run/spice-vdagentd to /run/spice-vdagentd.
(spice-vdagent-service-type): Specify a default value and fix indentation.
</span></span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2020-04-21 00:06:40 +0200'>2020-04-21</span></td><td><a href='/guix/commit/gnu/services/spice.scm?id=7d903d2ff7e17406c0650541f35e37a99dab8759'>services: Don't use the deprecated 'make-forkexec-constructor' call.</a><span class='msg-avail'>...<span class='msg-tooltip'>Passing 'make-forkexec-constructor' a string or several string arguments
has been deprecated since dmd 0.1.

* gnu/services/base.scm (rngd-service-type): In 'start' method, pass a
list as the first argument to 'make-forkexec-constructor'.
* gnu/services/desktop.scm (bluetooth-shepherd-service): Likewise.
* gnu/services/spice.scm (spice-vdagent-shepherd-service): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2020-01-26 18:45:09 +0100'>2020-01-26</span></td><td><a href='/guix/commit/gnu/services/spice.scm?id=9a5edd02405b9ee70bc2f93b91483e8da2eadfd3'>services: Fix typo in spice-vdagent-service.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/services/spice.scm (spice-vdagent-service): Fix typo.

Signed-off-by: Danny Milosavljevic &lt;dannym@scratchpost.org&gt;
</span></span></td><td>Damien Cassou</td></tr>