test-runner: Add 'dispatch' command

This will only wait for events to be dispatched and processed by the server
without waiting for client processing.

Reuse the code for the wait command too.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/307

src/tests/test-runner.c

@@ -86,6 +86,24 @@ test_case_loop_quit (gpointer data)
   return FALSE;
 }
 
+static gboolean
+test_case_dispatch (TestCase *test,
+                    GError  **error)
+{
+  /* Wait until we've done any outstanding queued up work.
+   * Though we add this as BEFORE_REDRAW, the iteration that runs the
+   * BEFORE_REDRAW idles will proceed on and do the redraw, so we're
+   * waiting until after *all* frame processing.
+   */
+  meta_later_add (META_LATER_BEFORE_REDRAW,
+                  test_case_loop_quit,
+                  test,
+                  NULL);
+  g_main_loop_run (test->loop);
+
+  return TRUE;
+}
+
 static gboolean
 test_case_wait (TestCase *test,
                 GError  **error)
@@ -102,16 +120,8 @@ test_case_wait (TestCase *test,
     if (!test_client_wait (value, error))
       return FALSE;
 
-  /* Then wait until we've done any outstanding queued up work.
+  /* Then wait until we've done any outstanding queued up work. */
-   * Though we add this as BEFORE_REDRAW, the iteration that runs the
+  test_case_dispatch (test, error);
-   * BEFORE_REDRAW idles will proceed on and do the redraw, so we're
-   * waiting until after *all* frame processing.
-   */
-  meta_later_add (META_LATER_BEFORE_REDRAW,
-                  test_case_loop_quit,
-                  test,
-                  NULL);
-  g_main_loop_run (test->loop);
 
   /* Then set an XSync counter ourselves and and wait until
    * we receive the resulting event - this makes sure that we've
@@ -560,6 +570,14 @@ test_case_do (TestCase *test,
       if (!test_case_wait (test, error))
         return FALSE;
     }
+  else if (strcmp (argv[0], "dispatch") == 0)
+    {
+      if (argc != 1)
+        BAD_COMMAND("usage: %s", argv[0]);
+
+      if (!test_case_dispatch (test, error))
+        return FALSE;
+    }
   else if (strcmp (argv[0], "sleep") == 0)
     {
       guint64 interval;