Media Library selected items duplicated (counter)

Patch attached.

Thanks for the patch. We need a few more steps to reproduce (is there custom code?) and a merge request.

Changes are made on on 11.x (our main development branch) first, and are then back ported as needed according to our policies.

Yes custom code was being used, the custom code was a simply making a request to a controller that returned an AjaxOpenDialog response. And Ah sorry didn't know about the 11.x being the main branch.