Fix optional element regression (#5110)

* Fix optional element regression

* use vnode unless it is explicitly an option

packages/core-macro/src/props/mod.rs

@@ -201,8 +201,11 @@ mod field_info {
             if let Some(ref name) = field.ident {
                 let mut builder_attr = field_defaults.with(&field.attrs)?;
 
-                // children field is automatically defaulted to None
-                if name == "children" {
+                let strip_option_auto = builder_attr.strip_option
+                    || !builder_attr.ignore_option && type_from_inside_option(&field.ty).is_some();
+
+                // children field is automatically defaulted to an empty VNode unless it is marked as optional (in which case it defaults to None)
+                if name == "children" && !strip_option_auto {
                     builder_attr.default =
                         Some(syn::parse(quote!(dioxus_core::VNode::empty()).into()).unwrap());
                 }
@@ -226,16 +229,14 @@ mod field_info {
                     builder_attr.auto_into = true;
                 }
 
-                // extended field is automatically empty
+                // If this is a child field or extends, default to Default::default() if a default isn't set
                 if !builder_attr.extends.is_empty() {
-                    builder_attr.default = Some(
-                        syn::parse(quote!(::core::default::Default::default()).into()).unwrap(),
-                    );
+                    builder_attr.default.get_or_insert_with(|| {
+                        syn::parse(quote!(::core::default::Default::default()).into()).unwrap()
+                    });
                 }
 
                 // auto detect optional
-                let strip_option_auto = builder_attr.strip_option
-                    || !builder_attr.ignore_option && type_from_inside_option(&field.ty).is_some();
                 if !builder_attr.strip_option && strip_option_auto {
                     builder_attr.strip_option = true;
                     // only change the default if it isn't manually set above

packages/core-macro/tests/rsx.rs

@@ -44,6 +44,8 @@ mod test_default_into {
         #[props(default = Some("abc".into()))]
         pub opt_default: Option<String>,
 
+        pub opt_element: Option<Element>,
+
         // Test no default
         #[props(into)]
         pub some_data: bool,