evdev: Get key state from kernel on vt enter

We need this to correctly initialize compositor key state, modifier state and
to send the right keys in the key enter event.

src/evdev.c

@@ -557,6 +557,45 @@ device_removed(struct evdev_input_device *device)
 	free(device);
 }
 
+static void
+evdev_notify_keyboard_focus(struct evdev_input *input)
+{
+	struct evdev_input_device *device;
+	struct wl_array keys;
+	unsigned int i, set;
+	char evdev_keys[(KEY_CNT + 7) / 8], all_keys[(KEY_CNT + 7) / 8];
+	uint32_t *k;
+	int ret;
+
+	memset(all_keys, 0, sizeof all_keys);
+	wl_list_for_each(device, &input->devices_list, link) {
+		memset(evdev_keys, 0, sizeof evdev_keys);
+		ret = ioctl(device->fd,
+			    EVIOCGKEY(sizeof evdev_keys), evdev_keys);
+		if (ret < 0) {
+			fprintf(stderr, "failed to get keys for device %s\n",
+				device->devnode);
+			continue;
+		}
+		for (i = 0; i < ARRAY_LENGTH(evdev_keys); i++)
+			all_keys[i] |= evdev_keys[i];
+	}
+
+	wl_array_init(&keys);
+	for (i = 0; i < KEY_CNT; i++) {
+		set = all_keys[i >> 3] & (1 << (i & 7));
+		if (set) {
+			k = wl_array_add(&keys, sizeof *k);
+			*k = i;
+		}
+	}
+
+	notify_keyboard_focus(&input->base.input_device,
+			      weston_compositor_get_time(), &keys);
+
+	wl_array_release(&keys);
+}
+
 void
 evdev_add_devices(struct udev *udev, struct weston_input_device *input_base)
 {
@@ -585,6 +624,8 @@ evdev_add_devices(struct udev *udev, struct weston_input_device *input_base)
 	}
 	udev_enumerate_unref(e);
 
+	evdev_notify_keyboard_focus(input);
+
 	if (wl_list_empty(&input->devices_list)) {
 		fprintf(stderr,
 			"warning: no input devices on entering Weston. "
@@ -716,6 +757,9 @@ evdev_remove_devices(struct weston_input_device *input_base)
 
 	wl_list_for_each_safe(device, next, &input->devices_list, link)
 		device_removed(device);
+
+	notify_keyboard_focus(&input->base.input_device,
+			      weston_compositor_get_time(), NULL);
 }
 
 void