sftp-server: treat junctions as directory symlinks?

Hi folks.

Please answer the following

"OpenSSH for Windows" version
((Get-Item (Get-Command sshd).Source).VersionInfo.FileVersion)
7.7.2.2

Server OperatingSystem
((Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows nt\CurrentVersion\" -Name ProductName).ProductName)
Windows 10 Home

Client OperatingSystem
Linux Mint 19.2 with sshfs 2.8 and FUSE 2.9.7

What is failing
Backups (or simple traversals using /usr/bin/find) try to recurse without termination condition when traversing an sshfs mount of a Windows 10 system, if the directory hierarchy contains a junction.

Expected output
A complete backup, or successful /usr/bin/find.

Actual output
find: '/mymount/windows-10/C:/Documents and Settings/Dan Stromberg/AppData/Local/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Microsoft/Windows Sidebar': Bad message
find: '/mymount/windows-10/C:/Documents and Settings/Dan Stromberg/AppData/Local/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Microsoft/WindowsApps': Bad message
Inhaled 10000 filenames for progress report - can use --progress-report minimal to disable inhalation
find: '/mymount/windows-10/C:/Documents and Settings/Default User/AppData/Local/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Application Data/Microsoft/Windows Sidebar': Bad message

It seems like a fix would be to treat junctions as directory symlinks in Windows' sftp-server, instead of treating junctions as just another directory.

Thanks!

Start by examining the Windows sftp-server handling of directory junctions and reproduce the issue through an sshfs mount with find or a backup traversal. Done means junctions no longer cause recursive paths such as repeated Application Data entries, and complete traversal succeeds.