RichTextArea with russian links in Firefox

When I create a russian language link (for example “добровольцыроссии.рф”) in a RichTextArea component using Firefox browser I get an unusable link that looks like <a href="http://добровольцыроссии.рф">link</a> in resulting html text.
In IE and Chromium-based browsers such links work fine.
Is there any setting parameter or workaround to fix?
CUBA Platform 6.10.9

Hello. Thank you for reporting the problem. We have created an issue.

I see that issue is closed already. How can I get the fix in 6.10.x?

We could backport it but there are no concrete release dates for 6.10.11 yet.