Pressing 'enter' in the linkpicker folder search causes an error

Reproduction path:

• Fire up the CMS quickstart war.
• Goto document/articles/myarticle1 and press edit
• Click on the body field and select the text.
• Use the internal link picker to create a link
• Type some text and press enter.

This will end up in an blank page and a stack is thrown on the command-line.