Link creates span element with massive class attribute

[raybellis]

Describe the bug
We've ended up with a pad with a link whose HTML ends up looking like this with a class attribute over 1MB in length:

<span class="url-url-url-url-url-url-url-url-url-url-url-url-url-url-url-url-url-url-,,url-,,url-url-,,url-,,url-url-url-,,url-,,url-url-,,url-,,url-url-url-url-,,url-,,url-url-,,url-,,url-url-url-,,url-,,url-url-,,url-,,url-url-url-url-url-,,url-,,url-url-,,url-,,url-url...........

We only noticed this because attempting to copy this pad (with copy and paste) into a new one caused the receiving pad to lose its socket connection (without any logged error) and forcibly reconnect, repeatedly.

To Reproduce
We don't have a reproduction for this.

Expected behavior
It should work ;)

Screenshots

Server (please complete the following information):

• Etherpad version: 2.25
• OS: FreeBSD 14.2
• Node.js version (node --version): 22.16.0
• npm version (npm --version): 10.9.2
• Is the server free of plugins: not currently

Desktop (please complete the following information):

• OS: [e.g. iOS] macOS
• Browser [e.g. chrome, safari] Chrome
• Version [e.g. 22] 137.0.7151.104

Additional context
Add any other context about the problem here.

[raybellis]

We do have ep_embedded_hyperlinks2 installed. It's possible that the unmerged c&p bug there is root cause, but in any event the resulting closing of the socket would seem to be an etherlite core issue.