[6.x] Rebuild a collection's entries when its sites change

src/Stache/Repositories/CollectionRepository.php

@@ -86,6 +86,10 @@ public function save(Collection $collection)
     {
         $this->store->save($collection);
 
+        if ($collection->isDirty('sites')) {
+            $this->stache->store('entries')->store($collection->handle())->clear();
+        }
+
         if ($collection->orderable()) {
             $this->stache->store('entries')->store($collection->handle())->index('order')->update();
         }

tests/Data/Entries/CollectionTest.php

@@ -552,6 +552,36 @@ public function it_saves_quietly()
         Event::assertNotDispatched(CollectionSaving::class);
     }
 
+    #[Test]
+    public function it_only_queries_entries_in_the_sites_it_was_saved_with()
+    {
+        // Like a real cache, hand out copies. The plain array store would hand back
+        // the collection being saved itself, and fetching it resets its dirty state.
+        config([
+            'cache.stores.stache-serializing' => ['driver' => 'array', 'serialize' => true],
+            'statamic.stache.cache_store' => 'stache-serializing',
+        ]);
+
+        $this->setSites([
+            'en' => ['url' => '/', 'locale' => 'en_US'],
+            'fr' => ['url' => '/fr/', 'locale' => 'fr_FR'],
+        ]);
+
+        $collection = tap(Facades\Collection::make('test')->sites(['en', 'fr']))->save();
+        Facades\Entry::make()->collection('test')->locale('en')->id('en-entry')->slug('en-entry')->save();
+        Facades\Entry::make()->collection('test')->locale('fr')->id('fr-entry')->slug('fr-entry')->save();
+
+        $queried = [];
+        Event::listen(CollectionSaved::class, function ($event) use (&$queried) {
+            $queried[] = $event->collection->queryEntries()->get()->map->id()->sort()->values()->all();
+        });
+
+        $collection->sites(['en'])->save();
+        $collection->sites(['en', 'fr'])->save();
+
+        $this->assertEquals([['en-entry'], ['en-entry', 'fr-entry']], $queried);
+    }
+
     #[Test]
     public function it_dispatches_collection_saved()
     {

tests/Feature/GraphQL/EntriesTest.php

@@ -79,13 +79,13 @@ public function it_queries_all_entries()
     #[Test]
     public function it_queries_all_entries_in_a_specific_site()
     {
-        $this->createEntries();
-
         $this->setSites([
             'en' => ['url' => 'http://localhost/', 'locale' => 'en'],
             'fr' => ['url' => 'http://localhost/fr/', 'locale' => 'fr'],
         ]);
 
+        $this->createEntries();
+
         Collection::find('events')->routes('/events/{slug}')->sites(['en', 'fr'])->save();
 
         EntryFactory::collection('events')->locale('fr')->origin('4')->id('44')->slug('event-two')->create();

tests/Feature/GraphQL/EntryTest.php

@@ -7,6 +7,7 @@
 use Facades\Statamic\CP\LivePreview;
 use Facades\Statamic\Fields\BlueprintRepository;
 use Facades\Tests\Factories\EntryFactory;
+use Orchestra\Testbench\Attributes\DefineEnvironment;
 use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Group;
 use PHPUnit\Framework\Attributes\Test;
@@ -269,13 +270,9 @@ public function it_queries_an_entry_by_uri()
     }
 
     #[Test]
+    #[DefineEnvironment('useMultipleSites')]
     public function it_queries_an_entry_in_a_specific_site()
     {
-        $this->setSites([
-            'en' => ['url' => 'http://localhost/', 'locale' => 'en'],
-            'fr' => ['url' => 'http://localhost/fr/', 'locale' => 'fr'],
-        ]);
-
         Collection::find('events')->routes('/events/{slug}')->sites(['en', 'fr'])->save();
 
         EntryFactory::collection('events')->locale('fr')->origin('4')->id('44')->slug('event-two')->create();
@@ -625,6 +622,14 @@ public function adding_custom_field_to_an_implementation_does_not_add_it_to_the_
             ]]]);
     }
 
+    protected function useMultipleSites()
+    {
+        $this->setSites([
+            'en' => ['url' => 'http://localhost/', 'locale' => 'en'],
+            'fr' => ['url' => 'http://localhost/fr/', 'locale' => 'fr'],
+        ]);
+    }
+
     private function createStructuredCollection()
     {
         $collection = Collection::find('events');