Minor Description
Attached keynote file, without the *.key extension, should be detected as "application/vnd.apple.keynote.13" but is being detected as "application/vnd.apple.unknown.13".
The IWork13PackageParser.detect(ZipFile) method iterates over zip entries and calls detectIfPossible(ZipEntry) multiple times. Inside the last method, the check for "Index/MasterSlide-" or "Index/Slide-" files should work, they are found inside the attached file. But since those entries can appear in arbitrary order, the "Index/Document.iwa" entry is found before and then "application/vnd.apple.unknown.13" is returned. The fix is simply returning null when "Index/Document.iwa" entry is found.