FileProvider not including .DS_Store in directory iterator?

We've written a FileProvider plugin which displays the decrypted versions of encrypted files and folders stored in Dropbox. When removing encryption from a folder, we found one file was not properly decrypted -- it remained under its encrypted name (bPw4vCA6j5LOU,QuABQSsgmC.empfs). This turned out to be the folder's .DS_Store file. For some reason, a standard C++ iteration of the FileProvider folder did not include it.

Is this normal behaviour for FileProvider? For the record, the problem doesn't occur if we iterate a non-FileProvider directory on the filesystem (e.g. "/Users/orextest3/Dropbox/EMPSecureFolders/EncryptedOrexTest3/"), only if we iterate the FileProvider mounted folder ("/Users/orextest3/Library/CloudStorage/EMPSecure-EMPSecureDropbox/EMPSecureFolders/EncryptedOrexTest3/"). And in some cases, the problem doesn't occur (I suspect a Finder setting of some sort).

How can I ensure that these hidden files are included in an iteration?

For the record, the C++ iterator loop was implemented using boost::filesystem:

for (directory_iterator itr(source); itr!=directory_iterator(); ++itr)