tests: Skip buffer-count if EGL initialization fails

That is the case when using the headless backend. In the future
we may be able to use the mesa null egl platform but for now let's
just skip it.

Signed-off-by: Emilio Pozuelo Monfort <emilio.pozuelo@collabora.co.uk>

tests/buffer-count-test.c

@@ -31,6 +31,8 @@
 #include <wayland-egl.h>
 #include <GLES2/gl2.h>
 
+#define fail(msg) { fprintf(stderr, "%s failed\n", msg); return -1; }
+
 struct test_data {
 	struct client *client;
 
@@ -40,7 +42,7 @@ struct test_data {
 	EGLSurface egl_surface;
 };
 
-static void
+static int
 init_egl(struct test_data *test_data)
 {
 	struct wl_egl_window *native_window;
@@ -67,21 +69,24 @@ init_egl(struct test_data *test_data)
 
 	test_data->egl_dpy = eglGetDisplay((EGLNativeDisplayType)
 					   test_data->client->wl_display);
-	assert(test_data->egl_dpy);
+	if (!test_data->egl_dpy)
+		fail("eglGetDisplay");
 
-	ret = eglInitialize(test_data->egl_dpy, &major, &minor);
-	assert(ret == EGL_TRUE);
-	ret = eglBindAPI(EGL_OPENGL_ES_API);
-	assert(ret == EGL_TRUE);
+	if (eglInitialize(test_data->egl_dpy, &major, &minor) != EGL_TRUE)
+		fail("eglInitialize");
+	if (eglBindAPI(EGL_OPENGL_ES_API) != EGL_TRUE)
+		fail("eglBindAPI");
 
 	ret = eglChooseConfig(test_data->egl_dpy, config_attribs,
 			      &test_data->egl_conf, 1, &n);
-	assert(ret && n == 1);
+	if (!(ret && n == 1))
+		fail("eglChooseConfig");
 
 	test_data->egl_ctx = eglCreateContext(test_data->egl_dpy,
 					      test_data->egl_conf,
 					      EGL_NO_CONTEXT, context_attribs);
-	assert(test_data->egl_ctx);
+	if (!test_data->egl_ctx)
+		fail("eglCreateContext");
 
 	native_window =
 		wl_egl_window_create(surface->wl_surface,
@@ -95,7 +100,8 @@ init_egl(struct test_data *test_data)
 
 	ret = eglMakeCurrent(test_data->egl_dpy, test_data->egl_surface,
 			     test_data->egl_surface, test_data->egl_ctx);
-	assert(ret == EGL_TRUE);
+	if (ret != EGL_TRUE)
+		fail("eglMakeCurrent");
 
 	/* This test is specific to mesa 10.1 and later, which is the
 	 * first release that doesn't accidentally triple-buffer. */
@@ -108,6 +114,7 @@ init_egl(struct test_data *test_data)
 	if (major < 10 || (major == 10 && minor < 1))
 		skip("mesa version too old (%s)\n", str);
 
+	return 0;
 }
 
 TEST(test_buffer_count)
@@ -117,7 +124,9 @@ TEST(test_buffer_count)
 	int i;
 
 	test_data.client = client_create(10, 10, 10, 10);
-	init_egl(&test_data);
+	if (init_egl(&test_data) < 0)
+		skip("could not initialize egl, "
+		     "possibly using the headless backend\n");
 
 	/* This is meant to represent a typical game loop which is
 	 * expecting eglSwapBuffers to block and throttle the