There is a feature in Java "fix imports" and a similar feature called "fix namespaces" in xhtml files. This feature doesn't work in plain xml files, I thought that this should be working there too. If this is not a defect, than change it to enhancement, if it's implemented but not working anymore, than it is broken and defect.

Anyway, I expect the same behaviour as in xhtml files. I write
<a:test></a:test> and I got an error and can fix namespaces, where they will add

xmlns:a="..." to the top of it. In this case, I have a .tpl.html file for GWT and this is the header:

<ui:UiBinder xmlns:ui="urn:com.google.gwt.uibinder"
xmlns:g="urn:import.com.google.gwt.user.client.ui">