[modal] When two modals with allowMultiple: true are opened, clicking the dimmer on one will close both regardless of the closable setting on the first

[Merlin04]

Bug Report

I have two modals. Both of them have allowMultiple: true, and the first has closable: false. When I open the first one and then the second one, clicking on the dimmer closes both modals, not just the second one.

Steps to reproduce

1. Create two modals with allowMultiple: true, with the first one having closable set to false
2. Open the first one, then the second one
3. Click on the dimmer

Expected result

Only the second modal closes, with the first remaining open

Actual result

Both modals close, even though I set closable on the first modal to false

Testcase

https://jsfiddle.net/15bd4x20/

Version

2.8.4

[Merlin04]

From looking at the source code this appears to be intended behavior, there should be an option to disable it.