Steps to reproduce:

1. Edit a page, and go to the wiki markup editor
2. Enter a word (e.g. "test"), and highlight it
3. Press the "Insert link" button
4. Observe that the word you highlighted now is set as alias for the new link
5. Press either "History", "Recent Modified", "External Link" or "Attachments"
6. The alias field now becomes empty

If you try the same in the Rich Text editor, it seems to work well.

According to CONF-10122, the problem should have been solved, but it looks to me like a part of the problem still exists.