LibWeb: Tidy up apply_clip_overflow_rect() a little

Avoid possible null optional dereference when creating border radius
clipper, and avoid creating clipper if the clip rect is empty (which
prevents some debug spam). Also remove an unnecessary lambda.

Userland/Libraries/LibWeb/Painting/PaintableBox.cpp

@@ -349,19 +349,16 @@ void PaintableBox::apply_clip_overflow_rect(PaintContext& context, PaintPhase ph
     auto overflow_x = computed_values().overflow_x();
     auto overflow_y = computed_values().overflow_y();
 
-    auto clip_overflow = [&] {
-        if (!m_clipping_overflow) {
-            context.painter().save();
-            context.painter().add_clip_rect(context.rounded_device_rect(*clip_rect).to_type<int>());
-            m_clipping_overflow = true;
-        }
-    };
+    if (!clip_rect.has_value())
+        return;
 
-    if (clip_rect.has_value()) {
-        clip_overflow();
+    if (!m_clipping_overflow) {
+        context.painter().save();
+        context.painter().add_clip_rect(context.rounded_device_rect(*clip_rect).to_type<int>());
+        m_clipping_overflow = true;
     }
 
-    if (overflow_y == CSS::Overflow::Hidden && overflow_x == CSS::Overflow::Hidden) {
+    if (!clip_rect->is_empty() && overflow_y == CSS::Overflow::Hidden && overflow_x == CSS::Overflow::Hidden) {
         auto border_radii_data = normalized_border_radii_data(ShrinkRadiiForBorders::Yes);
         if (border_radii_data.has_any_radius()) {
             auto corner_clipper = BorderRadiusCornerClipper::create(context, context.rounded_device_rect(*clip_rect), border_radii_data, CornerClip::Outside, BorderRadiusCornerClipper::UseCachedBitmap::No);
@@ -369,7 +366,6 @@ void PaintableBox::apply_clip_overflow_rect(PaintContext& context, PaintPhase ph
                 dbgln("Failed to create overflow border-radius corner clipper: {}", corner_clipper.error());
                 return;
             }
-            clip_overflow();
             m_overflow_corner_radius_clipper = corner_clipper.release_value();
             m_overflow_corner_radius_clipper->sample_under_corners(context.painter());
         }