Focus not carried to the first tabbable element when a modal is opened

Problem/Motivation

When we open a modal form by clicking any link or button, we expect the focus to be present on the first tabbable element on the modal, but the focus stays on the link.

Steps to reproduce

1. Go to admin/structure/block
2. Click on Place block button
the focus stays on Place block button instead of first tabbable element.

Proposed resolution

In the form where we are adding the button/link, add 'data-disable-refocus' => 'true’,
to the attributes. This is not a generic solution find a generic one, otherwise we will have to add data-disable-refocus to all the places where we have modal links.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet