fix(history): count child pushes in joint session history

moli-core/tests/history_child.rs

@@ -306,7 +306,7 @@ async fn assert_child_location_navigation_stays_window_local(
         page.serialize_html_async()
             .await
             .unwrap()
-            .contains("data-top-history-unchanged=\"false\""),
+            .contains("data-top-history-unchanged=\"true\""),
         "{}",
         page.serialize_html_async().await.unwrap()
     );
@@ -314,13 +314,13 @@ async fn assert_child_location_navigation_stays_window_local(
         page.serialize_html_async()
             .await
             .unwrap()
-            .contains("data-child-history-advanced=\"true\"")
+            .contains("data-child-history-advanced=\"false\"")
     );
     assert!(
         page.serialize_html_async()
             .await
             .unwrap()
-            .contains("data-child-current-entry-index=\"1\""),
+            .contains("data-child-current-entry-index=\"0\""),
         "{}",
         page.serialize_html_async().await.unwrap()
     );

moli-renderer-v8/src/context_bootstrap/history_runtime/length.rs

@@ -8,38 +8,22 @@ pub(crate) fn increment_top_level_history_length_for_runtime_owner<'s>(
     scope: &mut v8::PinScope<'s, '_>,
     owner: v8::Local<'s, v8::Object>,
 ) {
-    if !runtime_window_uses_top_level_history_model(scope, owner)
-        && let Some(child_history) = window_history_for_holder(scope, owner)
-        && let Some(child_length) = history_length_number(scope, child_history)
-    {
-        set_top_level_history_length_at_least_for_runtime_owner(
-            scope,
-            owner,
-            child_length.max(0.0),
-        );
+    let child_history = (!runtime_window_uses_top_level_history_model(scope, owner))
+        .then(|| window_history_for_holder(scope, owner))
+        .flatten();
+    let top_window = runtime_top_window_owner(scope, owner);
+    let Some(history) = window_history_for_holder(scope, top_window) else {
         return;
+    };
+    let current_length = history_length_number(scope, history)
+        .unwrap_or(0.0)
+        .max(0.0);
+    let next_length = current_length + 1.0;
+    set_history_length(scope, history, next_length);
+    if let Some(child_history) = child_history {
+        let child_length = history_length_number(scope, child_history)
+            .unwrap_or(0.0)
+            .max(0.0);
+        set_history_length(scope, child_history, child_length.max(next_length));
     }
-    let top_window = runtime_top_window_owner(scope, owner);
-    let Some(history) = window_history_for_holder(scope, top_window) else {
-        return;
-    };
-    let current_length = history_length_number(scope, history)
-        .unwrap_or(0.0)
-        .max(0.0);
-    set_history_length(scope, history, current_length + 1.0);
-}
-
-pub(crate) fn set_top_level_history_length_at_least_for_runtime_owner<'s>(
-    scope: &mut v8::PinScope<'s, '_>,
-    owner: v8::Local<'s, v8::Object>,
-    length: f64,
-) {
-    let top_window = runtime_top_window_owner(scope, owner);
-    let Some(history) = window_history_for_holder(scope, top_window) else {
-        return;
-    };
-    let current_length = history_length_number(scope, history)
-        .unwrap_or(0.0)
-        .max(0.0);
-    set_history_length(scope, history, current_length.max(length.max(0.0)));
 }

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

@@ -113,6 +113,7 @@ pub(super) fn handle_navigation_navigate_cross_document<'s>(
         child_handle,
         next_url.as_str(),
         entry_seed,
+        matches!(mutation, NavigationHistoryMutation::Push),
     );
     host.sync_existing_child_browsing_context_window_state(scope, child_handle);
     navigation_signal

moli-renderer-v8/src/context_bootstrap/navigation_mutation/local.rs

@@ -44,7 +44,10 @@ pub(crate) fn apply_local_window_location_navigation<'s>(
             let _ = next_entries.set_index(scope, next_index, next_entry.into());
             set_history_entries(scope, history, next_entries);
             set_history_index(scope, history, next_index);
-            set_history_length_at_least_visible_entries(scope, history, next_entries);
+            // Cross-document pushes do not enter the joint session history
+            // until the new Document commits. Keep the pending child's local
+            // projection current without advancing the traversable yet.
+            set_history_length_from_visible_entries(scope, history, next_entries);
             set_history_state(scope, history, state);
             set_navigation_current_entry(scope, navigation, next_entry);
             dispatch_navigation_currententrychange(scope, navigation, previous_entry, Some("push"));

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

@@ -227,7 +227,6 @@ pub(super) fn set_history_length_from_visible_entries<'s>(
 ) {
     let length = history_length_floor_from_visible_entries(scope, history, entries);
     set_history_length(scope, history, length);
-    set_top_history_length_at_least(scope, history, length);
 }
 
 pub(super) fn set_history_length_at_least_visible_entries<'s>(
@@ -239,9 +238,18 @@ pub(super) fn set_history_length_at_least_visible_entries<'s>(
     let current_length = history_length_number(scope, history)
         .unwrap_or(0.0)
         .max(0.0);
-    let length = current_length.max(length);
-    set_history_length(scope, history, length);
-    set_top_history_length_at_least(scope, history, length);
+    let owner = runtime_window_owner(scope, history);
+    if runtime_window_uses_top_level_history_model(scope, owner) {
+        set_history_length(scope, history, current_length.max(length));
+        return;
+    }
+
+    // Same-document child pushes commit synchronously. They add one entry to
+    // the traversable's joint session history even when another child has
+    // already made the top-level length larger than this child's local list.
+    super::increment_top_level_history_length_for_runtime_owner(scope, owner);
+    let joint_length = history_length_floor_from_visible_entries(scope, history, entries);
+    set_history_length(scope, history, current_length.max(length).max(joint_length));
 }
 
 fn history_length_floor_from_visible_entries<'s>(
@@ -270,22 +278,3 @@ fn history_length_floor_from_visible_entries<'s>(
         .max(0.0);
     visible_length.max(top_length)
 }
-
-fn set_top_history_length_at_least<'s>(
-    scope: &mut v8::PinScope<'s, '_>,
-    history: v8::Local<'s, v8::Object>,
-    length: f64,
-) {
-    let owner = runtime_window_owner(scope, history);
-    if runtime_window_uses_top_level_history_model(scope, owner) {
-        return;
-    }
-    let top_window = runtime_top_window_owner(scope, owner);
-    let Some(top_history) = window_history_for_holder(scope, top_window) else {
-        return;
-    };
-    let current_length = history_length_number(scope, top_history)
-        .unwrap_or(0.0)
-        .max(0.0);
-    set_history_length(scope, top_history, current_length.max(length));
-}

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

@@ -532,5 +532,6 @@ fn queue_child_cross_document_traversal(
         child_handle,
         target_url,
         seed,
+        false,
     );
 }

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

@@ -640,6 +640,7 @@ impl JsContextHost {
                 };
                 entry.clear_cached_snapshot();
                 entry.clear_completed_document_network();
+                entry.clear_pending_top_level_history_length_increment();
                 self.reject_replaced_service_worker_child_client_navigation(
                     handle,
                     format!("Cannot navigate to URL: {error}"),
@@ -694,6 +695,7 @@ impl JsContextHost {
                     body_activity,
                 };
             };
+            self.commit_pending_child_joint_history_push(scope, handle);
             initial_classic_ready_work = install.initial_classic_ready_work;
             parser_stop_action = install.parser_stop_action;
             owner_transition = Some(install.owner_transition);

moli-renderer-v8/src/native_bridge/context_host/child_frame_navigation/commands.rs

@@ -29,6 +29,7 @@ impl JsContextHost {
                 entry.replace_navigation_in_entry_seed(&url);
             } else {
                 entry.apply_navigation_to_entry_seed(&url);
+                entry.mark_pending_top_level_history_length_increment();
             }
         }
         self.sync_existing_child_browsing_context_runtime_surface_from_seed(scope, handle);
@@ -51,6 +52,7 @@ impl JsContextHost {
                 entry.replace_navigation_in_entry_seed(&request.url);
             } else {
                 entry.apply_navigation_to_entry_seed(&request.url);
+                entry.mark_pending_top_level_history_length_increment();
             }
         }
         self.sync_existing_child_browsing_context_runtime_surface_from_seed(scope, handle);
@@ -75,6 +77,9 @@ impl JsContextHost {
         );
         if let Some(entry) = self.child_browsing_contexts.get_mut(&handle) {
             entry.apply_queued_navigation_to_entry_seed(&url, replace_current);
+            if !replace_current {
+                entry.mark_pending_top_level_history_length_increment();
+            }
         }
         self.queue_child_browsing_context_navigation_to_url(handle, &url)
     }
@@ -98,6 +103,7 @@ impl JsContextHost {
         handle: DomHandle,
         resolved_url: &str,
         entry_seed: NavigationHistoryEntrySeed,
+        increments_joint_history: bool,
     ) -> bool {
         if !self.child_browsing_contexts.contains_key(&handle) {
             return false;
@@ -107,6 +113,9 @@ impl JsContextHost {
         };
         if let Some(entry) = self.child_browsing_contexts.get_mut(&handle) {
             entry.replace_navigation_entry_seed_and_clear_pending_history_increment(entry_seed);
+            if increments_joint_history {
+                entry.mark_pending_top_level_history_length_increment();
+            }
         }
         if self
             .set_child_browsing_context_pending_navigation(
@@ -134,6 +143,7 @@ impl JsContextHost {
         };
         if let Some(entry) = self.child_browsing_contexts.get_mut(&handle) {
             entry.apply_deferred_navigation_to_entry_seed(&url);
+            entry.mark_pending_top_level_history_length_increment();
         }
         if self
             .set_child_browsing_context_pending_navigation(
@@ -162,6 +172,7 @@ impl JsContextHost {
         );
         if let Some(entry) = self.child_browsing_contexts.get_mut(&handle) {
             entry.apply_deferred_navigation_to_entry_seed(&request.url);
+            entry.mark_pending_top_level_history_length_increment();
         }
         if self
             .set_child_browsing_context_pending_navigation(

moli-renderer-v8/src/native_bridge/context_host/child_frame_navigation/commit.rs

@@ -416,10 +416,6 @@ impl JsContextHost {
             self.sync_existing_child_browsing_context_window_state(scope, handle);
             return None;
         }
-        let increment_top_level_history_length = self
-            .child_browsing_contexts
-            .get_mut(&handle)
-            .is_some_and(|entry| entry.take_pending_top_level_history_length_increment());
         self.clear_child_browsing_context_pending_navigation(handle);
         self.clear_pending_form_submission_child_target(handle);
         let commit_result = self.commit_child_document_bootstrap_or_start_load(
@@ -429,13 +425,30 @@ impl JsContextHost {
             navigation_load,
             ChildDocumentNavigationInitiator::BrowsingContext,
         );
+        if commit_result
+            .as_ref()
+            .is_some_and(|result| result.state == ChildDocumentCommitState::Ready)
+        {
+            self.commit_pending_child_joint_history_push(scope, handle);
+        }
         self.sync_existing_child_browsing_context_window_state(scope, handle);
-        if increment_top_level_history_length
+        commit_result
+    }
+
+    pub(in crate::native_bridge::context_host) fn commit_pending_child_joint_history_push(
+        &mut self,
+        scope: &mut v8::PinScope<'_, '_>,
+        handle: DomHandle,
+    ) {
+        let increments_joint_history = self
+            .child_browsing_contexts
+            .get_mut(&handle)
+            .is_some_and(|entry| entry.take_pending_top_level_history_length_increment());
+        if increments_joint_history
             && let Some(window) = self.child_browsing_context_window_wrapper(scope, handle)
         {
             increment_top_level_history_length_for_runtime_owner(scope, window);
         }
-        commit_result
     }
 
     pub(crate) fn queue_child_browsing_context_javascript_url_execution(

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

@@ -22,11 +22,7 @@ impl JsContextHost {
         &self,
         handle: DomHandle,
     ) -> bool {
-        let seed_is_initial_about_blank = self
-            .child_browsing_contexts
-            .get(&handle)
-            .is_some_and(ChildBrowsingContextEntry::navigation_seed_is_initial_about_blank_commit);
-        seed_is_initial_about_blank
+        self.child_current_document_is_initial_empty(handle)
             && self
                 .child_browsing_context_current_url(handle)
                 .is_some_and(|url| moli_url::is_about_blank(&url))

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

@@ -11830,6 +11830,64 @@ fn no_src_iframe_initial_about_blank_has_a_quirks_empty_document() {
     );
 }
 
+#[test]
+fn child_joint_history_pushes_accumulate_across_distinct_frames() {
+    let mut vm = new_storage_test_vm("https://joint-child-length.test/page.html");
+
+    vm.exec(
+        r#"
+const first = document.createElement('iframe');
+first.srcdoc = '<p>first</p>';
+(document.body || document.documentElement || document).appendChild(first);
+globalThis.__firstJointLengthFrame = first;
+"#,
+        None,
+    )
+    .expect("first child setup should evaluate");
+    vm.drain_pending_child_frame_work_for_test();
+    assert_eq!(
+        vm.eval(
+            r#"
+(() => {
+  const child = __firstJointLengthFrame.contentWindow;
+  const before = history.length;
+  child.history.pushState(null, '', '#first');
+  return [before, history.length, child.history.length].join('|');
+})()
+"#,
+        )
+        .expect("first child history push should evaluate"),
+        "1|2|2"
+    );
+
+    vm.exec(
+        r#"
+__firstJointLengthFrame.remove();
+const second = document.createElement('iframe');
+second.srcdoc = '<p>second</p>';
+(document.body || document.documentElement || document).appendChild(second);
+globalThis.__secondJointLengthFrame = second;
+"#,
+        None,
+    )
+    .expect("second child setup should evaluate");
+    vm.drain_pending_child_frame_work_for_test();
+    assert_eq!(
+        vm.eval(
+            r#"
+(() => {
+  const child = __secondJointLengthFrame.contentWindow;
+  const before = history.length;
+  child.history.pushState(null, '', '#second');
+  return [before, history.length, child.history.length].join('|');
+})()
+"#,
+        )
+        .expect("second child history push should evaluate"),
+        "2|3|3"
+    );
+}
+
 #[tokio::test]
 async fn top_history_back_routes_to_child_joint_history_entry() {
     let loader = ResourceRequestClient::new(&moli_fetch::FetchConfig::default()).expect("loader");