LibWeb: Start fleshing out update document for history step application

Userland/Libraries/LibWeb/DOM/Document.cpp

@@ -3489,4 +3489,37 @@ Painting::ViewportPaintable* Document::paintable()
     return static_cast<Painting::ViewportPaintable*>(Node::paintable());
 }
 
+// https://html.spec.whatwg.org/multipage/browsing-the-web.html#update-document-for-history-step-application
+void Document::update_for_history_step_application(JS::NonnullGCPtr<HTML::SessionHistoryEntry> entry, bool do_not_reactive, size_t script_history_length, size_t script_history_index)
+{
+    // 1. Let documentIsNew be true if document's latest entry is null; otherwise false.
+    auto document_is_new = !m_latest_entry;
+
+    // 2. Let documentsEntryChanged be true if document's latest entry is not entry; otherwise false.
+    auto documents_entry_changed = m_latest_entry != entry;
+
+    // 3. Set document's history object's index to scriptHistoryIndex.
+    history()->m_index = script_history_index;
+
+    // 4. Set document's history object's length to scriptHistoryLength.
+    history()->m_length = script_history_length;
+
+    // 5. If documentsEntryChanged is true, then:
+    if (documents_entry_changed) {
+        // FIXME: Implement this.
+    }
+
+    // 6. If documentIsNew is true, then:
+    if (document_is_new) {
+        // FIXME: 1. Try to scroll to the fragment for document.
+        // FIXME: 2. At this point scripts may run for the newly-created document document.
+    }
+
+    // 7. Otherwise, if documentsEntryChanged is false and doNotReactivate is false, then:
+    if (!documents_entry_changed && !do_not_reactive) {
+        // FIXME: 1. Assert: entriesForNavigationAPI is given.
+        // FIXME: 2. Reactivate document given entry and entriesForNavigationAPI.
+    }
+}
+
 }

Userland/Libraries/LibWeb/DOM/Document.h

@@ -531,6 +531,8 @@ public:
 
     HTML::SourceSnapshotParams snapshot_source_snapshot_params() const;
 
+    void update_for_history_step_application(JS::NonnullGCPtr<HTML::SessionHistoryEntry>, bool do_not_reactive, size_t script_history_length, size_t script_history_index);
+
 protected:
     virtual void initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
@@ -730,6 +732,9 @@ private:
     RefPtr<Core::Timer> m_active_refresh_timer;
 
     bool m_temporary_document_for_fragment_parsing { false };
+
+    // https://html.spec.whatwg.org/multipage/browsing-the-web.html#latest-entry
+    JS::GCPtr<HTML::SessionHistoryEntry> m_latest_entry;
 };
 
 template<>

Userland/Libraries/LibWeb/HTML/Navigable.cpp

@@ -1330,23 +1330,31 @@ WebIDL::ExceptionOr<void> Navigable::navigate_to_a_fragment(AK::URL const& url,
     // 7. Let entryToReplace be navigable's active session history entry if historyHandling is "replace", otherwise null.
     auto entry_to_replace = history_handling == HistoryHandlingBehavior::Replace ? active_session_history_entry() : nullptr;
 
-    // FIXME: 8. Let history be navigable's active document's history object.
+    // 8. Let history be navigable's active document's history object.
+    auto history = active_document()->history();
 
-    // FIXME: 9. Let scriptHistoryIndex be history's index.
+    // 9. Let scriptHistoryIndex be history's index.
+    auto script_history_index = history->m_index;
 
-    // FIXME: 10. Let scriptHistoryIndex be history's index.
+    // 10. Let scriptHistoryLength be history's length.
+    auto script_history_length = history->m_length;
 
     // 11. If historyHandling is "push", then:
     if (history_handling == HistoryHandlingBehavior::Push) {
         // FIXME: 1. Set history's state to null.
-        // FIXME: 2. Increment scriptHistoryIndex.
-        // FIXME: 3. Set scriptHistoryLength to scriptHistoryIndex + 1.
+
+        // 2. Increment scriptHistoryIndex.
+        script_history_index++;
+
+        // 3. Set scriptHistoryLength to scriptHistoryIndex + 1.
+        script_history_length = script_history_index + 1;
     }
 
     // 12. Set navigable's active session history entry to historyEntry.
     m_active_session_history_entry = history_entry;
 
-    // FIXME: 13. Update document for history step application given navigable's active document, historyEntry, true, scriptHistoryIndex, and scriptHistoryLength.
+    // 13. Update document for history step application given navigable's active document, historyEntry, true, scriptHistoryIndex, and scriptHistoryLength.
+    active_document()->update_for_history_step_application(*history_entry, true, script_history_length, script_history_index);
 
     // FIXME: 14. Update the navigation API entries for a same-document navigation given navigation, historyEntry, and historyHandling.
 

Userland/Libraries/LibWeb/HTML/TraversableNavigable.cpp

@@ -407,14 +407,14 @@ void TraversableNavigable::apply_the_history_step(int step, Optional<SourceSnaps
         navigable->set_ongoing_navigation({});
 
         // 8. Let (scriptHistoryLength, scriptHistoryIndex) be the result of getting the history object length and index given traversable and targetStep.
-        auto [script_history_length, script_history_index] = get_the_history_object_length_and_index(target_step);
-        (void)script_history_length;
-        (void)script_history_index;
+        auto history_object_length_and_index = get_the_history_object_length_and_index(target_step);
+        auto script_history_length = history_object_length_and_index.script_history_length;
+        auto script_history_index = history_object_length_and_index.script_history_index;
 
         // FIXME: 9. Append navigable to navigablesThatMustWaitBeforeHandlingSyncNavigation.
 
         // 10. Queue a global task on the navigation and traversal task source given navigable's active window to run the steps:
-        queue_global_task(Task::Source::NavigationAndTraversal, *navigable->active_window(), [&, target_entry, navigable, displayed_document, update_only = changing_navigable_continuation.update_only] {
+        queue_global_task(Task::Source::NavigationAndTraversal, *navigable->active_window(), [&, target_entry, navigable, displayed_document, update_only = changing_navigable_continuation.update_only, script_history_length, script_history_index] {
             // NOTE: This check is not in the spec but we should not continue navigation if navigable has been destroyed.
             if (navigable->has_been_destroyed())
                 return;
@@ -439,8 +439,10 @@ void TraversableNavigable::apply_the_history_step(int step, Optional<SourceSnaps
             // FIXME: 2. If targetEntry's document is not equal to displayedDocument, then queue a global task on the navigation and traversal task source given targetEntry's document's
             //           relevant global object to perform the following step. Otherwise, continue onward to perform the following step within the currently-queued task.
 
-            // FIXME: 3. Update document for history step application given targetEntry's document, targetEntry, changingNavigableContinuation's update-only, scriptHistoryLength, and
-            //           scriptHistoryIndex.
+            // 3. Update document for history step application given targetEntry's document, targetEntry, changingNavigableContinuation's update-only, scriptHistoryLength, and
+            //    scriptHistoryIndex and entriesForNavigationAPI.
+            //    FIXME: Pass entriesForNavigationAPI
+            target_entry->document_state->document()->update_for_history_step_application(*target_entry, update_only, script_history_length, script_history_index);
 
             // 4. Increment completedChangeJobs.
             completed_change_jobs++;

Userland/Libraries/LibWeb/HTML/TraversableNavigable.h

@@ -34,8 +34,8 @@ public:
     void set_system_visibility_state(VisibilityState);
 
     struct HistoryObjectLengthAndIndex {
-        size_t script_history_length;
-        size_t script_history_index;
+        u64 script_history_length;
+        u64 script_history_index;
     };
     HistoryObjectLengthAndIndex get_the_history_object_length_and_index(int) const;