Basic version of Windows-flavored SSH run

lib/vagrant/action/builtin/ssh_run.rb

@@ -36,7 +36,17 @@ module Vagrant
 
           # Get the command and wrap it in a login shell
           command = ShellQuote.escape(env[:ssh_run_command], "'")
-          command = "#{env[:machine].config.ssh.shell} -c '#{command}'"
+
+          # This will always default to 'bash -l' unless it is explicitly set in
+          # the Vagrantfile, because the base SSHConfig object has already been
+          # finalized.
+          shell = env[:machine].config.ssh.shell
+
+          if env[:machine].config.vm.communicator == :winssh && shell == "cmd"
+            command = "#{shell} /C #{command}"
+          else
+            command = "#{shell} -c '#{command}'"
+          end
 
           # Execute!
           opts = env[:ssh_opts] || {}

test/unit/vagrant/action/builtin/ssh_run_test.rb

@@ -18,8 +18,14 @@ describe Vagrant::Action::Builtin::SSHRun do
     )
   end
 
+  let(:vm) do
+    double("vm",
+      communicator: nil
+    )
+  end
+
   # Configuration mock
-  let(:config) { double("config", ssh: ssh) }
+  let(:config) { double("config", ssh: ssh, vm: vm) }
 
   let(:machine) do
     double("machine",
@@ -80,4 +86,23 @@ describe Vagrant::Action::Builtin::SSHRun do
     env[:ssh_run_command] = "echo test"
     described_class.new(app, env).call(env)
   end
+
+  context "when using the WinSSH communicator" do
+    before do
+      expect(vm).to receive(:communicator).and_return(:winssh)
+      expect(ssh).to receive(:shell).and_return("cmd")
+    end
+
+    it "should use Windows-specific flags for cmd" do
+      ssh_info = { foo: :bar }
+      opts = {:extra_args=>["-t", "cmd /C dir"], :subprocess=>true}
+
+      expect(ssh_klass).to receive(:exec).
+        with(ssh_info, opts)
+
+      env[:ssh_info] = ssh_info
+      env[:ssh_run_command] = "dir"
+      described_class.new(app, env).call(env)
+    end
+  end
 end