Ignore exit code zero from activated services

A variety of system components have migrated from legacy init into DBus
service activation.  Many of these system components "daemonize", which
involves forking.  The DBus activation system treated an exit as an
activation failure, assuming that the child process which grabbed the
DBus name didn't run first.

While we're in here, also differentiate in this code path between the
servicehelper (system) versus direct activation (session) paths.  In
the session activation path our error message mentioned a helper
process which was confusing, since none was involved.

Based on a patch and debugging research from Ray Strode <rstrode@redhat.com>

5 files changed, 99 insertions, 4 deletions

diff --git a/test/data/valid-service-files/org.freedesktop.DBus.TestSuiteForkingEchoService.service.in b/test/data/valid-service-files/org.freedesktop.DBus.TestSuiteForkingEchoService.service.in
new file mode 100644
index 00000000..49fcac39
--- /dev/null
+++ b/test/data/valid-service-files/org.freedesktop.DBus.TestSuiteForkingEchoService.service.in
@@ -0,0 +1,3 @@
+[D-BUS Service]
+Name=org.freedesktop.DBus.TestSuiteForkingEchoService
+Exec=@TEST_SERVICE_BINARY@ org.freedesktop.DBus.TestSuiteForkingEchoService fork
diff --git a/test/name-test/Makefile.am b/test/name-test/Makefile.am
index 1c73b877..d8e72d14 100644
--- a/test/name-test/Makefile.am
+++ b/test/name-test/Makefile.am
@@ -10,7 +10,7 @@ else
 TESTS=
 endif
 
-EXTRA_DIST=run-test.sh run-test-systemserver.sh test-wait-for-echo.py
+EXTRA_DIST=run-test.sh run-test-systemserver.sh test-wait-for-echo.py test-activation-forking.py
 
 if DBUS_BUILD_TESTS
 
diff --git a/test/name-test/run-test.sh b/test/name-test/run-test.sh
index fba45584..4eb24252 100755
--- a/test/name-test/run-test.sh
+++ b/test/name-test/run-test.sh
@@ -50,3 +50,9 @@ ${DBUS_TOP_BUILDDIR}/libtool --mode=execute $DEBUG $DBUS_TOP_BUILDDIR/test/name-
 
 echo "running test-shutdown"
 ${DBUS_TOP_BUILDDIR}/libtool --mode=execute $DEBUG $DBUS_TOP_BUILDDIR/test/name-test/test-shutdown || die "test-shutdown failed"
+
+echo "running test activation forking"
+if ! python $DBUS_TOP_SRCDIR/test/name-test/test-activation-forking.py; then
+  echo "Failed test-activation-forking"
+  exit 1
+fi
diff --git a/test/name-test/test-activation-forking.py b/test/name-test/test-activation-forking.py
new file mode 100644
index 00000000..0d820754
--- /dev/null
+++ b/test/name-test/test-activation-forking.py
@@ -0,0 +1,60 @@
+#!/usr/bin/env python
+
+import os,sys
+
+try:
+    import gobject
+    import dbus
+    import dbus.mainloop.glib
+except:
+    print "Failed import, aborting test"
+    sys.exit(0)
+
+dbus.mainloop.glib.DBusGMainLoop(set_as_default=True)
+loop = gobject.MainLoop()
+
+exitcode = 0
+
+bus = dbus.SessionBus()
+bus_iface = dbus.Interface(bus.get_object('org.freedesktop.DBus', '/org/freedesktop/DBus'), 'org.freedesktop.DBus')
+
+o = bus.get_object('org.freedesktop.DBus.TestSuiteForkingEchoService', '/org/freedesktop/TestSuite')
+i = dbus.Interface(o, 'org.freedesktop.TestSuite')
+
+# Start it up
+reply = i.Echo("hello world")
+print "TestSuiteForkingEchoService initial reply OK"
+
+def ignore(*args, **kwargs):
+    pass
+
+# Now monitor for exits, when that happens, start it up again.
+# The goal here is to try to hit any race conditions in activation.
+counter = 0
+def on_forking_echo_owner_changed(name, old, new):
+    global counter
+    global o
+    global i
+    if counter > 10:
+        print "Activated 10 times OK, TestSuiteForkingEchoService pass"
+        loop.quit()
+        return
+    counter += 1
+    if new == '':
+        o = bus.get_object('org.freedesktop.DBus.TestSuiteForkingEchoService', '/org/freedesktop/TestSuite')
+        i = dbus.Interface(o, 'org.freedesktop.TestSuite')
+        i.Echo("counter %r" % counter)
+        i.Exit(reply_handler=ignore, error_handler=ignore)
+
+bus_iface.connect_to_signal('NameOwnerChanged', on_forking_echo_owner_changed, arg0='org.freedesktop.DBus.TestSuiteForkingEchoService')
+
+i.Exit(reply_handler=ignore, error_handler=ignore)
+
+def check_counter():
+    if counter == 0:
+        print "Failed to get NameOwnerChanged for TestSuiteForkingEchoService"
+        sys.exit(1)
+gobject.timeout_add(15000, check_counter)
+
+loop.run()
+sys.exit(0)
diff --git a/test/test-service.c b/test/test-service.c
index c9f58390..a57bf9c2 100644
--- a/test/test-service.c
+++ b/test/test-service.c
@@ -398,7 +398,33 @@ main (int    argc,
   DBusError error;
   int result;
   DBusConnection *connection;
-  
+  const char *name;
+  dbus_bool_t do_fork;
+
+  if (argc != 3)
+    {
+      name = "org.freedesktop.DBus.TestSuiteEchoService";
+      do_fork = FALSE;
+    }
+  else
+    {
+      name = argv[1];
+      do_fork = strcmp (argv[2], "fork") == 0;
+    }
+
+  /* The bare minimum for simulating a program "daemonizing"; the intent
+   * is to test services which move from being legacy init scripts to
+   * activated services.
+   * https://bugzilla.redhat.com/show_bug.cgi?id=545267
+   */
+  if (do_fork)
+    {
+      pid_t pid = fork ();
+      if (pid != 0)
+        exit (0);
+      sleep (1);
+    }
+
   dbus_error_init (&error);
   connection = dbus_bus_get (DBUS_BUS_STARTER, &error);
   if (connection == NULL)
@@ -433,8 +459,8 @@ main (int    argc,
     if (d != (void*) 0xdeadbeef)
       die ("dbus_connection_get_object_path_data() doesn't seem to work right\n");
   }
-  
-  result = dbus_bus_request_name (connection, "org.freedesktop.DBus.TestSuiteEchoService",
+
+  result = dbus_bus_request_name (connection, name,
                                   0, &error);
   if (dbus_error_is_set (&error))
     {