Folder copy silently fails to copy children when folder name begins with a dot (“.”) and the destination resides in a shared folder

[pupSci]

Setup:
VB version 5.1.22 or 5.1.23 r115382
Host: macOS Sierra 10.12.5 or 10.12.4
Guest: Windows 10

Issue:
On Windows 10 guest copying a folder with a name beginning with a dot (“.”) to a shared folder results in an incomplete copy. For example a Visual Studio project folder with a “.vs” child folder. VBox seems to stop copying once it hits the .vs folder children. No error is displayed in File Explorer. Win 7 guest does not have this issue.

Steps to reproduce:

Setup Win 10 guest.
Install Guest additions.
Create a shared folder on host and mount it in guest.
Using a command prompt create a folder with a name beginning with a dot (e.g. md “.test”).
Create a file under .test such as “New Test Document.txt”.
In File Explorer right-click .test and select copy.
Right-click a destination folder on a shared folder, right-click and and paste.

Notice .test is created but “New Test Document.txt” is not present under it.
Also, using the command prompt to rename .test results in “The system cannot find the file specified”.