tests/stacking: Change primary monitor handling

The first monitor in stacking tests is the primary monitor but that
doesn't have to stay this way forever. Instead of special casing the
name "primary" to refer to whatever monitor happens to be the primary
monitor, we add an `assert_primary_monitor` command to verify that the
monitor that should be the primary monitor actually is.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2748>

src/backends/meta-monitor.h

@@ -112,6 +112,7 @@ gboolean meta_monitor_is_active (MetaMonitor *monitor);
 META_EXPORT_TEST
 MetaOutput * meta_monitor_get_main_output (MetaMonitor *monitor);
 
+META_EXPORT_TEST
 gboolean meta_monitor_is_primary (MetaMonitor *monitor);
 
 gboolean meta_monitor_supports_underscanning (MetaMonitor *monitor);

src/tests/stacking/click-to-focus-and-raise.metatest

@@ -1,4 +1,4 @@
-resize_monitor primary 800 600
+resize_monitor default 800 600
 
 num_workspaces 2
 

src/tests/stacking/client-resize-respect-constraints.metatest

@@ -4,7 +4,7 @@
 #  3. Resize such that the following resize will extend beyond the screen
 #  4. Check that the window was moved to the position that would allow it to fit on the screen
 
-resize_monitor primary 800 600
+resize_monitor default 800 600
 
 new_client w wayland
 create w/1 csd

src/tests/stacking/map-on-hotplug.metatest

@@ -7,7 +7,7 @@ freeze w/1
 resize w/1 100 200
 show w/1 async
 
-resize_monitor primary 1024 768
+resize_monitor default 1024 768
 
 wait
 

src/tests/stacking/workspace-only-on-primary-focus.metatest

@@ -1,5 +1,6 @@
-resize_monitor primary 800 600
+resize_monitor default 800 600
 add_monitor secondary 800 600
+assert_primary_monitor default
 
 num_workspaces 2
 

src/tests/test-runner.c

@@ -104,7 +104,7 @@ test_case_new (MetaContext *context)
                                                   g_free,
                                                   g_object_unref);
   monitor = meta_create_test_monitor (context, 800, 600, 60.0);
-  g_hash_table_insert (test->virtual_monitors, g_strdup ("primary"), monitor);
+  g_hash_table_insert (test->virtual_monitors, g_strdup ("default"), monitor);
 
   return test;
 }
@@ -1069,6 +1069,31 @@ test_case_do (TestCase *test,
 
       g_hash_table_insert (test->virtual_monitors, g_strdup (argv[1]), monitor);
     }
+  else if (strcmp (argv[0], "assert_primary_monitor") == 0)
+    {
+      MetaVirtualMonitor *virtual_monitor;
+      MetaOutput *output;
+      MetaMonitor *monitor;
+
+      if (argc != 2)
+        BAD_COMMAND ("usage: %s <monitor-id>", argv[0]);
+
+      virtual_monitor = g_hash_table_lookup (test->virtual_monitors, argv[1]);
+      if (!virtual_monitor)
+        BAD_COMMAND ("Unknown monitor %s", argv[1]);
+
+      output = meta_virtual_monitor_get_output (virtual_monitor);
+      monitor = meta_output_get_monitor (output);
+
+      if (!meta_monitor_is_primary (monitor))
+        {
+          g_set_error (error,
+                       META_TEST_CLIENT_ERROR,
+                       META_TEST_CLIENT_ERROR_ASSERTION_FAILED,
+                       "Monitor %s is not the primary monitor", argv[1]);
+          return FALSE;
+        }
+    }
   else if (strcmp (argv[0], "num_workspaces") == 0)
     {
       if (argc != 2)