Change Details

Steps to reproduce: * Go to a template page (e.g. https://www.mediawiki.org/w/index.php?title=Template:Extension&action=edit) and click edit * Click the templatedata button * Click on a parameter * Type something in label and/or description Expected: The typed text should appear in the text field Observed: The input will be cleared immediatly, so it's impossible to insert text there.