synced_folders/rsync: convert path to cygpath on Windows

lib/vagrant/util/platform.rb

@@ -33,11 +33,19 @@ module Vagrant
         # path on Windows machines in Cygwin.
         #
         # @return [String]
-        def cygwin_windows_path(path)
-          return path if !cygwin?
+        def cygwin_windows_path(path, **opts)
+          return path if !cygwin? && !opts[:force]
 
+          begin
+            # First try the real cygpath
             process = Subprocess.execute("cygpath", "-w", "-l", "-a", path.to_s)
-          process.stdout.chomp
+            return process.stdout.chomp
+          rescue Errors::CommandUnavailableWindows
+            # Sometimes cygpath isn't available (msys). Instead, do what we
+            # can with bash tricks.
+            process = Subprocess.execute("bash", "-c", "cd #{path} && pwd")
+            return process.stdout.chomp
+          end
         end
 
         # This checks if the filesystem is case sensitive. This is not a

plugins/synced_folders/rsync/helper.rb

@@ -13,6 +13,12 @@ module VagrantPlugins
         hostpath  = File.expand_path(hostpath, machine.env.root_path)
         hostpath  = Vagrant::Util::Platform.fs_real_path(hostpath).to_s
 
+        if Vagrant::Util::Platform.windows?
+          # rsync for Windows expects cygwin style paths
+          hostpath = Vagrant::Util::Platform.cygwin_windows_path(
+            hostpath, force: true)
+        end
+
         # Connection information
         username = ssh_info[:username]
         host     = ssh_info[:host]

test/unit/plugins/synced_folders/rsync/helper_test.rb

@@ -21,6 +21,11 @@ describe VagrantPlugins::SyncedFolderRSync::RsyncHelper do
 
   before do
     machine.stub(guest: guest)
+
+    # Don't do all the crazy Cygwin stuff
+    Vagrant::Util::Platform.stub(:cygwin_windows_path) do |path, **opts|
+      path
+    end
   end
 
   describe "#rsync_single" do
@@ -44,6 +49,23 @@ describe VagrantPlugins::SyncedFolderRSync::RsyncHelper do
       subject.rsync_single(machine, ssh_info, opts)
     end
 
+    it "doesn't call cygwin_windows_path on non-Windows" do
+      Vagrant::Util::Platform.stub(windows?: false)
+      Vagrant::Util::Platform.should_not_receive(:cygwin_windows_path)
+      subject.rsync_single(machine, ssh_info, opts)
+    end
+
+    it "calls cygwin_windows_path on Windows" do
+      Vagrant::Util::Platform.stub(windows?: true)
+      Vagrant::Util::Platform.should_receive(:cygwin_windows_path).and_return("foo")
+
+      Vagrant::Util::Subprocess.should_receive(:execute).with do |*args|
+        expect(args[args.length - 3]).to eql("foo")
+      end
+
+      subject.rsync_single(machine, ssh_info, opts)
+    end
+
     it "raises an error if the exit code is non-zero" do
       Vagrant::Util::Subprocess.stub(
         execute: Vagrant::Util::Subprocess::Result.new(1, "", ""))