Issue #7750 duplicate

Autocompletion of usernames with hyphens in markup-type-markdown editor (BB-8923)

created an issue

When referencing a username with a hyphen in by using the '@us-ername' format in a markup-type-markdown editor it appears to only use the first component i.e. 'us' ignoring the whole string. This is even the case when the username is selected from the dialog that appears to aid in autocompletion.