// are technically zero-byte files, must not have any associated file
		// data. We previously tried failing here if f.CompressedSize64 != 0,
		// but it turns out that a number of implementations (namely, the Java
		// jar tool) don't properly set the storage method on directories
		// resulting in a file with compressed size > 0 but uncompressed size ==
		// 0. We still want to fail when a directory has associated uncompressed