fix(navigation): reload idle initial-empty iframe documents

moli-renderer-v8/src/context_bootstrap/location_navigation.rs

@@ -260,7 +260,7 @@ fn navigate_location_object_with_source_element_and_child_navigate_event<'s>(
     if matches!(kind, LocationNavigationKind::Reload)
         && matches!(
             navigation_reload_admission(scope, owner),
-            NavigationReloadAdmission::NoCommittedHistoryItem
+            NavigationReloadAdmission::PendingInitialAttributeNavigation
         )
     {
         return;

moli-renderer-v8/src/context_bootstrap/navigation_reload.rs

@@ -1,15 +1,13 @@
 use super::navigation_window::child_browsing_context_handle_for_runtime_owner;
 use super::*;
 
-/// Whether the current Document owns a committed session-history item that
-/// can be used as the source of a reload.
-///
-/// An initial-empty child Document is installed synchronously before its first
-/// real navigation and deliberately has no committed history item. Reloading
-/// it must therefore leave any deferred iframe attribute navigation alone.
+/// A deferred iframe attribute navigation still belongs to the initial empty
+/// Document. Reloading that Document must leave the pending attribute load
+/// alone; an ordinary initial about:blank iframe has an active history entry
+/// and can be reloaded.
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub(super) enum NavigationReloadAdmission {
-    NoCommittedHistoryItem,
+    PendingInitialAttributeNavigation,
     Admitted,
 }
 
@@ -23,8 +21,8 @@ pub(super) fn navigation_reload_admission<'s>(
     let Some(host_ptr) = context_host_ptr_from_global_bridge(scope) else {
         return NavigationReloadAdmission::Admitted;
     };
-    if unsafe { &*host_ptr }.child_current_document_is_initial_empty(handle) {
-        NavigationReloadAdmission::NoCommittedHistoryItem
+    if unsafe { &*host_ptr }.child_initial_empty_has_pending_attribute_navigation(handle) {
+        NavigationReloadAdmission::PendingInitialAttributeNavigation
     } else {
         NavigationReloadAdmission::Admitted
     }

moli-renderer-v8/src/context_bootstrap/navigation_traversal.rs

@@ -254,10 +254,10 @@ pub(super) fn navigation_reload_callback<'s>(
     }
     if matches!(
         navigation_reload_admission(scope, owner),
-        NavigationReloadAdmission::NoCommittedHistoryItem
+        NavigationReloadAdmission::PendingInitialAttributeNavigation
     ) {
-        // Navigation API methods on an initial-empty Document return a
-        // correctly-shaped result whose promises intentionally never settle.
+        // Reloading the initial empty Document must not replace a deferred
+        // iframe attribute navigation. Its result promises remain pending.
         rv.set(navigation_pending_result(scope).into());
         return;
     }

moli-renderer-v8/src/native_bridge/context_host/child_frame_runtime/window.rs

@@ -836,6 +836,17 @@ impl JsContextHost {
             .is_some_and(crate::frame_owner_model::DocumentCreationKind::is_initial_empty)
     }
 
+    pub(crate) fn child_initial_empty_has_pending_attribute_navigation(
+        &self,
+        handle: DomHandle,
+    ) -> bool {
+        self.child_current_document_is_initial_empty(handle)
+            && self
+                .child_browsing_contexts
+                .get(&handle)
+                .is_some_and(|entry| entry.pending_attribute_bootstrap_commit())
+    }
+
     pub(crate) fn retire_child_frame_realm_materialization_request(
         &mut self,
         handle: DomHandle,

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

@@ -2260,8 +2260,49 @@ __domainAccessFrame.src = globalThis.__replacementDomainChildUrl;
         vec!["/replacement.html"]
     );
 }
+
 #[test]
-fn initial_empty_iframe_reload_uses_shared_no_history_admission() {
+fn initial_empty_iframe_reload_methods_replace_document_and_dispatch_load() {
+    for reload in ["location.reload()", "history.go(0)", "navigation.reload()"] {
+        let mut vm = new_storage_test_vm("https://initial-empty-reload.test/page.html");
+
+        vm.exec(
+            &format!(
+                r#"
+const frame = document.createElement('iframe');
+(document.body || document.documentElement || document).appendChild(frame);
+globalThis.__initialReloadFrame = frame;
+globalThis.__initialReloadDocument = frame.contentDocument;
+globalThis.__initialReloadLoads = 0;
+frame.onload = () => ++__initialReloadLoads;
+frame.contentWindow.{reload};
+"#
+            ),
+            None,
+        )
+        .expect("initial-empty iframe reload should evaluate");
+        assert!(
+            vm.has_pending_child_navigation_commit_for_test(),
+            "reloading an ordinary initial about:blank iframe must queue a navigation"
+        );
+
+        vm.drain_pending_child_frame_work_for_test();
+        assert_eq!(
+            vm.eval(
+                r#"[
+  __initialReloadFrame.contentDocument !== __initialReloadDocument,
+  __initialReloadLoads,
+  __initialReloadFrame.contentWindow.location.href
+].join('|')"#,
+            )
+            .expect("initial-empty iframe reload result should evaluate"),
+            "true|1|about:blank"
+        );
+    }
+}
+
+#[test]
+fn initial_empty_iframe_reload_preserves_pending_attribute_navigation_result_shape() {
     let mut vm = new_storage_test_vm("https://initial-empty-reload.test/page.html");
 
     let setup = vm
@@ -2269,6 +2310,9 @@ fn initial_empty_iframe_reload_uses_shared_no_history_admission() {
             r#"
 (() => {
   const frame = document.createElement('iframe');
+  frame.loading = 'lazy';
+  frame.hidden = true;
+  frame.src = '/pending-attribute-navigation.html';
   (document.body || document.documentElement || document).appendChild(frame);
   const child = frame.contentWindow;
   const log = [];
@@ -2337,6 +2381,7 @@ fn initial_empty_iframe_reload_uses_shared_no_history_admission() {
         "about:blank"
     );
 }
+
 #[test]
 fn non_initial_about_blank_iframe_remains_reloadable() {
     let mut vm = new_storage_test_vm("https://non-initial-blank-reload.test/page.html");