Steps to reproduce
1. Set dl.store.impl=com.liferay.portlet.documentlibrary.store.DBStore in portal-ext.properties
2. In Documents and Media, add a document "Doc1" and attach a file "File1" and select Publish
3. In Documents and Media, add a document "Doc2" and select Publish
4. Add the Search Portlet to a page.
5. Search for Doc1 and Doc2.
Result: Doc 1 will return results, while Doc 2 will not.
This was also tested with AdvancedFileSystemStore, and that returned Doc 2.