When a username that starts with a number is mentioned, fullname isn't displayed.

[cyberjam]

Summary

When a username that starts with a number is mentioned, the fullname doesn't appear. Only @<username> is displayed.

Environment Information

• Device Name: iPhone 11 / Pixel 3a
• OS Version: iOS 17.0 / Android 14.0
• Mattermost App Version: 2.11.0 (Build 497) / 2.12.0 (Build 501)
• Mattermost Server Version: 8.1.7 (Build 7025434773) / 8.1.7 (Build 7025434773)

Steps to reproduce

Mention a username that starts with a number.

Expected behavior

When mentioning @123username that starts with a number, @fullname should be displayed.

Observed behavior (that appears unintentional)

Possible fixes

mattermost>commonmark.js>lib>inlines.js
mattermost>commonmark.js>dist>commonmark.js

• AS-IS
  var reAtMention = /^@([a-z][a-z0-9._-]*)/i;
• TO-BE
  var reAtMention = /^@([a-z0-9][a-z0-9._-]*)/i;

AS-IS	TO-BE

• append test

````````````````````````````````
 
```````````````````````````````` example
This is an @123mention
.
<p>This is an <span data-mention-name="123mention" /></p>

AS-IS	TO-BE

If you need anything, just let me know ;)

[amyblais]

@cyberjam Are you able to reproduce this issue on our community server https://community.mattermost.com/?

[cyberjam]

@amyblais Thanks for reply. I reproduced this issue on mattermost community server. It is same.

Before	After

[amyblais]

Thanks, opened https://mattermost.atlassian.net/browse/MM-56555.

[cyberjam]

Thanks! If possible, I'd like to be assigned this issue.