libssh2 scp file transfer (eg. curl) fails to some server implementations (not OpenSSH)

Issue

• libssh2 scp file transfer (eg. curl) fails to some server implementations (not OpenSSH)

  # curl -v -L -u user:"" --insecure -T ~/file.txt scp://host.domain.com/file-curl-scp
  <snip>
  * Authentication complete
  * SSH CONNECT phase done
  * failed to send file
  * Connection #0 to host host.domain.com left intact
  curl: (79) failed to send file
  

• The libssh2 transfer may also fail; however curl exits with return code of zero. Was able to trigger this slightly different error message simply by using ~ to indicate user's home directory for file upload.

  # curl -v -L -u user:"" --insecure -T ~/file.txt scp://host.domain.com/~/file-curl-scp-tilde
  <snip>
  * Authentication complete
  * SSH CONNECT phase done
  } [data not shown]
  * We are completely uploaded and fine
  * Channel failed to close: -34 <------------------------- Actually FAILED!!!
  * Connection #0 to host host.domain.com left intact
  
  # echo $?
  0