[mutter/wip/carlosg/xwayland-startup-side-channel: 179/186] tests: Ensure MetaX11Display is initialized before running tests

[Carlos Garnacho <carlosg src gnome org>]

commit 613660c9a663a9a002a879334cb3cf715ed35aa2
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Nov 18 23:12:19 2019 +0100

    tests: Ensure MetaX11Display is initialized before running tests
    
    It might not be available right on initialization time if X11 is started
    asynchronously. As this is a requirement for our tests, ensure it is there
    before proceeding with the test.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/944

 src/tests/monitor-unit-tests.c |  2 ++
 src/tests/test-runner.c        |  9 +++++++++
 src/tests/test-utils.c         | 17 +++++++++++++++++
 src/tests/test-utils.h         |  2 ++
 4 files changed, 30 insertions(+)
---
diff --git a/src/tests/monitor-unit-tests.c b/src/tests/monitor-unit-tests.c
index b498d899f..7a0c4b1b6 100644
--- a/src/tests/monitor-unit-tests.c
+++ b/src/tests/monitor-unit-tests.c
@@ -342,6 +342,8 @@ create_monitor_test_clients (void)
 {
   GError *error = NULL;
 
+  test_wait_for_x11_display ();
+
   meta_x11_display_set_alarm_filter (meta_get_display ()->x11_display,
                                      monitor_tests_alarm_filter, NULL);
 
diff --git a/src/tests/test-runner.c b/src/tests/test-runner.c
index 7560c957e..d09d0abe6 100644
--- a/src/tests/test-runner.c
+++ b/src/tests/test-runner.c
@@ -61,11 +61,20 @@ test_case_alarm_filter (MetaX11Display        *x11_display,
   return FALSE;
 }
 
+static void
+wait_for_x11_display (MetaDisplay *display)
+{
+  while (!display->x11_display)
+    g_main_context_iteration (NULL, TRUE);
+}
+
 static TestCase *
 test_case_new (void)
 {
   TestCase *test = g_new0 (TestCase, 1);
 
+  wait_for_x11_display (meta_get_display ());
+
   meta_x11_display_set_alarm_filter (meta_get_display ()->x11_display,
                                      test_case_alarm_filter, test);
 
diff --git a/src/tests/test-utils.c b/src/tests/test-utils.c
index bc4b97f92..2bb772d5b 100644
--- a/src/tests/test-utils.c
+++ b/src/tests/test-utils.c
@@ -533,3 +533,20 @@ test_get_plugin_name (void)
   else
     return "libdefault";
 }
+
+void
+test_wait_for_x11_display (void)
+{
+  MetaDisplay *display;
+
+  display = meta_get_display ();
+  g_assert_nonnull (display);
+
+  if (display->x11_display)
+    return;
+
+  while (!display->x11_display)
+    g_main_context_iteration (NULL, TRUE);
+
+  g_assert_nonnull (display->x11_display);
+}
diff --git a/src/tests/test-utils.h b/src/tests/test-utils.h
index 2f1a73116..1710b98e0 100644
--- a/src/tests/test-utils.h
+++ b/src/tests/test-utils.h
@@ -84,4 +84,6 @@ void test_client_destroy (TestClient *client);
 
 const char * test_get_plugin_name (void);
 
+void test_wait_for_x11_display (void);
+
 #endif /* TEST_UTILS_H */