Allow for quoted SSH commands

This commit changes the ssh run class to use the WinSSH shell if that
shell is enabled.

lib/vagrant/action/builtin/ssh_run.rb

@@ -37,13 +37,17 @@ module Vagrant
           # Get the command and wrap it in a login shell
           command = ShellQuote.escape(env[:ssh_run_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 = env[:machine].config.winssh.shell
+          else
+            shell = env[:machine].config.ssh.shell
+          end
 
-          if env[:machine].config.vm.communicator == :winssh && shell == "cmd"
-            command = "#{shell} /C #{command}"
+          if shell == "cmd"
+            # Add an extra space to the command so cmd.exe quoting works
+            # properly
+            command = "#{shell} /C #{command} "
+            env[:tty] = false
           else
             command = "#{shell} -c '#{command}'"
           end

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

@@ -88,14 +88,34 @@ describe Vagrant::Action::Builtin::SSHRun do
   end
 
   context "when using the WinSSH communicator" do
+    let(:winssh) { double("winssh", shell: "foo") }
+
     before do
       expect(vm).to receive(:communicator).and_return(:winssh)
-      expect(ssh).to receive(:shell).and_return("cmd")
+      expect(config).to receive(:winssh).and_return(winssh)
     end
 
-    it "should use Windows-specific flags for cmd" do
+    it "should use the WinSSH shell for running ssh commands" do
       ssh_info = { foo: :bar }
-      opts = {:extra_args=>["-t", "cmd /C dir"], :subprocess=>true}
+      opts = {:extra_args=>["-t", "foo -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
+
+  context "when shell is cmd" do
+    before do
+      expect(ssh).to receive(:shell).and_return('cmd')
+    end
+
+    it "should use appropriate options for cmd" do
+      ssh_info = { foo: :bar }
+      opts = {:extra_args=>["cmd /C dir "], :subprocess=>true}
 
       expect(ssh_klass).to receive(:exec).
         with(ssh_info, opts)