input: Store touch position and time when we start an implicit touch grab
diff --git a/src/input.c b/src/input.c
index e533a58..f76fcb9 100644
--- a/src/input.c
+++ b/src/input.c
@@ -1056,6 +1056,14 @@
 		}
 
 		grab->interface->down(grab, time, touch_id, sx, sy);
+		if (seat->num_tp == 1) {
+			touch->grab_serial =
+				wl_display_get_serial(ec->wl_display);
+			touch->grab_time = time;
+			touch->grab_x = x;
+			touch->grab_y = y;
+		}
+
 		break;
 	case WL_TOUCH_MOTION:
 		es = (struct weston_surface *) touch->focus;