Deleting an element from a "full" hetero(?) list does not re-enable the "Add" button

Jenkins and plugins versions report

2.536+ Firefox

What Operating System are you using (both controller, and any agents involved in the problem)?

n/a

Reproduction steps

1. Find a descriptor list that restricts adding new elements, e.g., a Freestyle job's "Add post-build action".
2. Add all elements until all are added.
3. Observe that the "Add post-build action" becomes disabled.
4. Remove an element from the list

Expected Results

The "Add post-build action" becomes enabled.

Actual Results

It remains disabled until you click on it while it's disabled (???). This click can happen before or after you remove an element, but it only becomes enabled again when that element is removed.

Anything else?

In earlier releases (shown: 2.500) the button remained active even if all elements are disallowed.

In 2.530 and 2.535 (didn't look further) the button became disabled, but also correctly enabled once an element is removed.

In 2.536 and later, the button becomes disabled, but not enabled again until clicked. Likely caused by https://github.com/jenkinsci/jenkins/pull/10186.

Are you interested in contributing a fix?

No response