Window: fix first configure timeout handling

 river/Window.zig       | 6 ++++--
 rivercompat/Window.zig | 3 ++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/river/Window.zig b/river/Window.zig
index 9ae8d0a..e38f674 100644
--- a/river/Window.zig
+++ b/river/Window.zig
@@ -714,8 +714,10 @@ pub fn updateRenderingStart(window: *Window) void {
             node_v1.sendPosition(scheduled_box.x, scheduled_box.y);
         }
     }
-    if (window.rendering_scheduled.resend_dimensions or
-        scheduled_box.width != sent.box.width or scheduled_box.height != sent.box.height)
+    // The check for 0 width/height is necessary to handle timeout of the first configure sent.
+    if (!scheduled_box.empty() and
+        (window.rendering_scheduled.resend_dimensions or
+        scheduled_box.width != sent.box.width or scheduled_box.height != sent.box.height))
     {
         if (window.object) |window_v1| {
             window_v1.sendDimensions(scheduled_box.width, scheduled_box.height);
diff --git a/rivercompat/Window.zig b/rivercompat/Window.zig
index 2f64353..4aa2ede 100644
--- a/rivercompat/Window.zig
+++ b/rivercompat/Window.zig
@@ -145,7 +145,8 @@ pub fn updateWindowing(window: *Window, wm: *WindowManager) void {
 
 pub fn updateRendering(window: *Window, wm: *WindowManager) void {
     _ = wm;
-    {
+
+    if (window.rendering.width != 0 and window.rendering.height != 0) {
         window.shadow_surface.attach(window.shadow_buffer, 0, 0);
         window.shadow_surface.damageBuffer(0, 0, math.maxInt(i32), math.maxInt(i32));
         window.shadow_viewport.setDestination(window.rendering.width, window.rendering.height);