This is a weird bug, when you have a page called "test-one" for instance and you create a link ([test-one]) for this page in another page, the link gets like this: "[test-one|test-one]". Somehow Confluence seems to add a alias to the link automatically.

Steps to reproduce:

1. Create a page called Test
2. Create another page called test-one
3. In the Test page create a link like the following for the test-one page: [test-one]
4. Save the page. The link will work fine.
5. Edit the page, go to the Wiki Markup tab and observe the link became: "[test-one|test-one]"

This only happens to links with the "-" in the page title.