fix(range): preserve live ranges when creating Window realms

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

@@ -2,13 +2,6 @@ use super::selection::selection_update_composed_boundaries_for_child_removal;
 use super::*;
 use crate::document_runtime::DomHandle;
 
-pub(super) fn clear_live_range_registry(scope: &mut v8::PinScope<'_, '_>) {
-    let Some(host_ptr) = context_host_ptr_from_global_bridge(scope) else {
-        return;
-    };
-    unsafe { &mut *host_ptr }.clear_live_range_registry();
-}
-
 fn range_container_handle<'s>(
     scope: &mut v8::PinScope<'s, '_>,
     host_ptr: *mut JsContextHost,

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

@@ -14,7 +14,6 @@ use super::range_algorithms::{
     range_geometry_client_rects, range_geometry_dom_rect, range_insert_node_at_boundary,
     range_intersects_node_native, range_string_contents, range_surround_contents, root_handle,
 };
-use super::range_live::clear_live_range_registry;
 use super::*;
 
 mod accessors;
@@ -26,7 +25,7 @@ mod geometry;
 mod install;
 mod template;
 
-pub(super) use install::{install_range_template_bindings, reset_range_runtime_state};
+pub(super) use install::install_range_template_bindings;
 pub(super) use template::{
     build_abstract_range_template, build_range_constructor_template,
     build_static_range_constructor_template,

moli-renderer-v8/src/context_bootstrap/range_surface/install.rs

@@ -15,7 +15,6 @@ use super::content::{
     range_surround_contents_callback, range_to_string_callback,
 };
 use super::geometry::{range_get_bounding_client_rect_callback, range_get_client_rects_callback};
-use super::*;
 use crate::web_api_interfaces;
 use moli_webapi_declare::WebApiFunctionTemplate;
 
@@ -126,10 +125,6 @@ struct AbstractRangePrototypeDeclaration {
     common_ancestor_container: (),
 }
 
-pub(in crate::context_bootstrap) fn reset_range_runtime_state(scope: &mut v8::PinScope<'_, '_>) {
-    clear_live_range_registry(scope);
-}
-
 pub(in crate::context_bootstrap) fn install_range_template_bindings<'s>(
     scope: &mut v8::PinScope<'s, '_, ()>,
     template: v8::Local<'s, v8::FunctionTemplate>,

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

@@ -12,7 +12,6 @@ use super::{
     navigation_bootstrap::install_window_location_history_navigation_runtime_state,
     navigator_runtime::{bind_window_navigator_identity_seed, install_navigator_runtime_state},
     performance_runtime::install_default_window_performance_seed,
-    range_surface::reset_range_runtime_state,
     trusted_types::install_trusted_types_runtime_state,
     web_storage::{
         install_storage_runtime_state, window_local_storage_getter, window_session_storage_getter,
@@ -1956,7 +1955,6 @@ pub(crate) fn finish_context_bootstrap(
     install_window_global_accessors(scope, global);
 
     native_bridge::install_detached_bridge_methods(scope);
-    reset_range_runtime_state(scope);
     initialize_file_api_runtime_queues(scope, global)?;
     super::exposed_interfaces::capture_eager_intrinsic_interfaces(
         scope,

moli-renderer-v8/src/native_bridge/context_host/live_ranges.rs

@@ -1,10 +1,6 @@
 use super::*;
 
 impl JsContextHost {
-    pub(crate) fn clear_live_range_registry(&mut self) {
-        self.range_record_registry.clear();
-    }
-
     pub(crate) fn live_ranges_is_empty(&mut self) -> bool {
         self.range_record_registry.active_is_empty()
     }

moli-renderer-v8/src/native_bridge/context_host/range_records.rs

@@ -70,6 +70,8 @@ pub(super) struct RangeRecord {
     end: RangeBoundaryPoint,
 }
 
+// Shared by all realms in this JsContextHost. Creating another Window must not
+// invalidate existing wrappers; their weak finalizers retire individual records.
 pub(super) struct RangeRecordRegistry {
     lifetime_token: u64,
     active_live_records: HashSet<RangeRecordId>,
@@ -93,15 +95,6 @@ impl RangeRecordRegistry {
         }
     }
 
-    pub(super) fn clear(&mut self) {
-        self.drain_finalized_live_records();
-        self.active_live_records.clear();
-        self.live_record_wrappers.clear();
-        self.records.clear();
-        self.by_boundary_container.clear();
-        self.by_boundary_child_before.clear();
-    }
-
     pub(super) fn active_is_empty(&mut self) -> bool {
         self.drain_finalized_live_records();
         self.active_live_records.is_empty()

moli-renderer-v8/src/script_vm/tests/browser_api/events_selection_storage.rs

@@ -2650,6 +2650,18 @@ fn pointer_event_sequences_preserve_identity_and_secure_context_exposure() {
     assert_eq!(insecure, "false|function|false|true");
 }
 
+#[test]
+fn live_ranges_survive_initialization_of_child_and_sibling_realms() {
+    let mut vm = new_storage_test_vm("https://range-realm-lifetime.test/");
+    assert_eq!(
+        vm.eval(include_str!(
+            "../../../../tests/fixtures/range-realm-lifetime.js"
+        ))
+        .expect("new realms must preserve live ranges in existing documents"),
+        ""
+    );
+}
+
 #[test]
 fn character_data_setters_apply_replace_all_live_range_offsets() {
     let mut vm = new_storage_test_vm("https://character-data-range.test/");

moli-renderer-v8/tests/fixtures/range-realm-lifetime.js

@@ -0,0 +1,45 @@
+(() => {
+  const root = document.documentElement || document.appendChild(document.createElement('html'));
+  const body = document.body || root.appendChild(document.createElement('body'));
+  const fixture = body.appendChild(document.createElement('div'));
+  const text = fixture.appendChild(document.createTextNode('abcd'));
+  const range = document.createRange();
+  range.setStart(text, 1);
+  range.setEnd(text, 3);
+  const selection = getSelection();
+  selection.removeAllRanges();
+  selection.addRange(range);
+  const failures = [];
+  const check = (condition, label) => { if (!condition) failures.push(label); };
+
+  const frame = fixture.appendChild(document.createElement('iframe'));
+  const other = frame.contentWindow;
+  const doc = other.document;
+  const childBody = doc.body || doc.documentElement.appendChild(doc.createElement('body'));
+  const childText = childBody.appendChild(doc.createTextNode('wxyz'));
+  const childRange = new other.Range();
+  childRange.setStart(childText, 1);
+  childRange.setEnd(childText, 3);
+  const childSelection = other.getSelection();
+  childSelection.addRange(childRange);
+
+  const sibling = fixture.appendChild(document.createElement('iframe'));
+  sibling.contentDocument.body.appendChild(sibling.contentDocument.createElement('span'));
+  check(range.startContainer === text && range.startOffset === 1 &&
+    range.endContainer === text && range.endOffset === 3, 'parent range survives new realms');
+  check(childRange.startContainer === childText && childRange.startOffset === 1 &&
+    childRange.endContainer === childText && childRange.endOffset === 3, 'child range survives sibling realm');
+  check(selection.getRangeAt(0) === range && childSelection.getRangeAt(0) === childRange,
+    'selections retain associated range identity');
+
+  text.insertData(0, '!');
+  childText.deleteData(0, 1);
+  check(range.startOffset === 2 && range.endOffset === 4 && range.toString() === 'bc',
+    'parent range still tracks mutations');
+  check(childRange.startOffset === 0 && childRange.endOffset === 2 && childRange.toString() === 'xy',
+    'child range still tracks mutations');
+  const clone = childRange.cloneRange();
+  check(clone instanceof other.Range && clone.toString() === 'xy', 'child range remains usable in its realm');
+  fixture.remove();
+  return failures.join('\n');
+})()