vagrant ssh on Cygwin won't output DOS path file warnings

CHANGELOG.md

@@ -43,6 +43,7 @@ IMPROVEMENTS:
     environmental variable. [GH-1478]
   - Invalid settings are now caught and shown in a user-friendly way. [GH-1484]
   - Detect PuTTY Link SSH client on Windows and show an error. [GH-1518]
+  - `vagrant ssh` in Cygwin won't output DOS path file warnings.
 
 BUG FIXES:
 

lib/vagrant/util/ssh.rb

@@ -137,6 +137,10 @@ module Vagrant
         host_string = "#{options[:username]}@#{host_string}" if !plain_mode
         command_options.unshift(host_string)
 
+        # On Cygwin we want to get rid of any DOS file warnings because
+        # we really don't care since both work.
+        ENV["nodosfilewarning"] = "1" if Platform.cygwin?
+
         # Invoke SSH with all our options
         LOGGER.info("Invoking SSH: #{command_options.inspect}")
         SafeExec.exec("ssh", *command_options)