[6.x] Prevent server error when renaming asset that doesn't exist

src/Actions/RenameAsset.php

@@ -59,6 +59,10 @@ protected function fieldItems()
     {
         $asset = $this->items->first();
 
+        // The selected asset may no longer exist (e.g. it was renamed by a
+        // previous request), in which case there's nothing left to rename.
+        abort_unless($asset, 404);
+
         return [
             'filename' => [
                 'type' => 'text',

tests/Actions/RenameAssetTest.php

@@ -72,6 +72,15 @@ public function it_renames()
         $this->assertAssetExistsAndHasData('bravo.jpg', ['alt' => 'The alfa alt text']);
     }
 
+    #[Test]
+    public function it_404s_when_the_selected_asset_does_not_exist()
+    {
+        $this
+            ->actingAs(tap(User::make()->makeSuper())->save())
+            ->rename('does-not-exist.jpg', 'bravo')
+            ->assertNotFound();
+    }
+
     #[Test]
     public function it_fails_validation_if_provided_with_the_current_filename()
     {