display error if mount location is not found

repertory/repertory/src/ui/handlers.cpp

@@ -334,6 +334,7 @@ void handlers::handle_post_mount(auto &&req, auto &&res) const {
   } else {
     if (not utils::file::directory{location}.exists()) {
       res.status = http_error_codes::internal_error;
+      return;
     }
 
     launch_process(prov, name, fmt::format(R"("{}")", location), true);

web/repertory/lib/models/mount.dart

@@ -84,7 +84,7 @@ class Mount with ChangeNotifier {
         ),
       );
 
-      if (response.statusCode == 500) {
+      if (!unmount && response.statusCode == 500) {
         return false;
       }
 

web/repertory/lib/widgets/mount_widget.dart

@@ -163,7 +163,7 @@ class _MountWidgetState extends State<MountWidget> {
                                 _enabled = true;
                               });
 
-                              if (isActive || !context.mounted) {
+                              if (success || isActive || !context.mounted) {
                                 return;
                               }