Fix Results nofitifation for changes to nested collections

CHANGELOG.md

@@ -16,6 +16,7 @@
 * Query with @type does not support filtering on collections ([#7281](https://github.com/realm/realm-core/issues/7281), since 14.0.0-beta.0)
 * Query involving string operations on nested collections would not work ([#7282](https://github.com/realm/realm-core/issues/7282), since 14.0.0-beta.0)
 * Using ANY, ALL or NONE in a query on nested collections would throw an exception ([#7283](https://github.com/realm/realm-core/issues/7283), since 14.0.0-beta.0)
+* Results notifications does not report changes to inner collections ([#7335](https://github.com/realm/realm-core/issues/7335), since 14.0.0-beta.0)
 
 ### Breaking changes
 * If you want to query using @type operation, you must use 'objectlink' to match links to objects. 'object' is reserved for dictionary types.

src/realm/object-store/impl/results_notifier.cpp

@@ -393,6 +393,17 @@ void ListResultsNotifier::run()
         std::iota(m_run_indices->begin(), m_run_indices->end(), 0);
     }
 
+    if (m_change.paths.size()) {
+        if (auto coll = dynamic_cast<CollectionParent*>(m_list.get())) {
+            for (auto& p : m_change.paths) {
+                // Report changes in substructure as modifications on this list
+                auto ndx = coll->find_index(p[0]);
+                if (ndx != realm::not_found)
+                    m_change.modifications.add(ndx); // OK to insert same index again
+            }
+        }
+    }
+
     calculate_changes();
 }
 

test/object-store/list.cpp

@@ -1356,11 +1356,19 @@ TEST_CASE("nested List") {
         }
 
         SECTION("inserting in sub structure sends a change notifications") {
+            // Check that notifications on Results are correct
+            Results res = lst0.as_results();
+            CollectionChangeSet change1;
+            auto token_res = res.add_notification_callback([&](CollectionChangeSet c) {
+                change1 = c;
+            });
+
             auto token = require_change();
             write([&] {
                 lst0.get_dictionary(0).get_list("list").add(Mixed(42));
             });
             REQUIRE_INDICES(change.modifications, 0);
+            REQUIRE_INDICES(change1.modifications, 0);
             REQUIRE(!change.collection_was_cleared);
         }