fix(dom): initialize empty browsing contexts correctly

moli-renderer-v8/src/native_bridge/context_host/child_documents/initial_empty.rs

@@ -181,9 +181,11 @@ impl JsContextHost {
     }
 
     fn populate_initial_empty_child_html_document(&mut self, document_handle: DomHandle) {
-        let doctype =
-            self.dom_host_mut()
-                .create_document_type_for_document(document_handle, "html", "", "");
+        self.dom_host_mut()
+            .set_html_quirks_mode_for_parser_document(
+                document_handle,
+                html5ever::tree_builder::QuirksMode::Quirks,
+            );
         let html = self
             .dom_host_mut()
             .create_parser_element_without_attributes_for_document(
@@ -208,7 +210,6 @@ impl JsContextHost {
                 "http://www.w3.org/1999/xhtml".to_owned(),
                 None,
             );
-        assert!(self.dom_host_mut().append_child(document_handle, doctype));
         assert!(self.dom_host_mut().append_child(document_handle, html));
         assert!(self.dom_host_mut().append_child(html, head));
         assert!(self.dom_host_mut().append_child(html, body));

moli-renderer-v8/src/native_bridge/context_host/child_frames/lookup.rs

@@ -384,10 +384,17 @@ impl JsContextHost {
         &self,
         document_handle: DomHandle,
     ) -> Option<&str> {
-        self.child_browsing_context_host_for_document_handle(document_handle)
-            .and_then(|child_handle| self.child_browsing_contexts.get(&child_handle))
+        let child_handle = self.child_browsing_context_host_for_document_handle(document_handle)?;
+        if let Some(character_set) = self
+            .child_browsing_contexts
+            .get(&child_handle)
             .and_then(|entry| entry.cached_snapshot_ref())
             .map(|snapshot| snapshot.character_set.as_str())
+        {
+            return Some(character_set);
+        }
+        self.child_current_document_is_initial_empty(child_handle)
+            .then_some("UTF-8")
     }
 
     pub(crate) fn child_browsing_context_referrer_for_document_handle(

moli-renderer-v8/src/script_vm/tests/dom_elements/dom_surface.rs

@@ -632,7 +632,7 @@ fn transformed_constrained_iframe_routes_hover_click_and_wheel_in_child_coordina
               const frame = document.getElementById('input-frame');
               const child = frame.contentDocument;
               return JSON.stringify({
-                hovered: child.getElementById('hover-target').matches(':hover'),
+                hovered: child.getElementById('hover-target').matches('#hover-target:hover'),
                 wheelTop: child.getElementById('wheel-target').scrollTop,
                 rootTop: document.scrollingElement.scrollTop,
                 events: frame.contentWindow.__inputEvents
@@ -927,7 +927,7 @@ fn focusing_visible_child_target_does_not_scroll_partially_hidden_transformed_if
                 parentScroll: window.scrollY,
                 parentActive: document.activeElement === frame,
                 childActive: child.activeElement === child.getElementById('focus-target'),
-                hovered: child.getElementById('focus-target').matches(':hover'),
+                hovered: child.getElementById('focus-target').matches('#focus-target:hover'),
                 events: frame.contentWindow.__focusEvents
               });
             })()
@@ -11509,6 +11509,46 @@ fn no_src_iframe_initial_about_blank_load_is_synchronous_at_connection() {
     );
 }
 
+#[test]
+fn no_src_iframe_initial_about_blank_has_a_quirks_empty_document() {
+    let mut vm = new_storage_test_vm("https://iframe-initial-document.test/page.html");
+    vm.document_runtime
+        .set_document_character_set("windows-1252");
+
+    let result = vm
+        .eval(
+            r#"
+(() => {
+  const frame = document.createElement("iframe");
+  (document.body || document.documentElement || document).appendChild(frame);
+  const doc = frame.contentDocument;
+  return JSON.stringify({
+    compatMode: doc.compatMode,
+    contentType: doc.contentType,
+    readyState: doc.readyState,
+    documentURI: doc.documentURI,
+    url: doc.URL,
+    doctypeIsNull: doc.doctype === null,
+    characterSet: doc.characterSet,
+    documentChildCount: doc.childNodes.length,
+    documentElement: doc.documentElement.tagName,
+    documentElementChildCount: doc.documentElement.childNodes.length,
+    head: doc.documentElement.firstChild.tagName,
+    headChildCount: doc.head.childNodes.length,
+    body: doc.documentElement.lastChild.tagName,
+    bodyChildCount: doc.body.childNodes.length
+  });
+})()
+"#,
+        )
+        .expect("initial about:blank document shape should evaluate");
+
+    assert_eq!(
+        result,
+        r#"{"compatMode":"BackCompat","contentType":"text/html","readyState":"complete","documentURI":"about:blank","url":"about:blank","doctypeIsNull":true,"characterSet":"UTF-8","documentChildCount":1,"documentElement":"HTML","documentElementChildCount":2,"head":"HEAD","headChildCount":0,"body":"BODY","bodyChildCount":0}"#
+    );
+}
+
 #[tokio::test]
 async fn top_history_back_routes_to_child_joint_history_entry() {
     let loader = ResourceRequestClient::new(&moli_fetch::FetchConfig::default()).expect("loader");