(#8954) Split out cygwin path and ensure bin exists

This commit splits out the msys2 and cygwin path functions for
expanding a path with the cygpath tool. It also ensures that the tool
itself exists when the Which class is called so that it doesn't attempt
to escape slashes on nil.

lib/vagrant/util/platform.rb

@@ -98,21 +98,20 @@ module Vagrant
         end
 
         # This takes any path and converts it from a Windows path to a
-        # Cygwin or msys style path.
+        # Cygwin style path.
         #
         # @param [String] path
         # @return [String]
         def cygwin_path(path)
           begin
-            # We have to revert to the old env
-            # path here, otherwise it looks like
-            # msys2 ends up using the wrong cygpath
-            # binary and ends up with a `/cygdrive`
-            # when it doesn't exist in msys2
-            original_path_env = ENV['PATH']
-            ENV['PATH'] = ENV['VAGRANT_OLD_ENV_PATH']
             cygpath = Vagrant::Util::Which.which("cygpath")
+            if cygpath.nil?
+              # If Which can't find it, just attempt to invoke it directly
+              cygpath = "cygpath"
+            else
               cygpath.gsub!("/", '\\')
+            end
+
             process = Subprocess.execute(
               cygpath, "-u", "-a", path.to_s)
             return process.stdout.chomp
@@ -125,14 +124,29 @@ module Vagrant
               "--norc",
               "-c", "cd #{Shellwords.escape(path)} && pwd")
             return process.stdout.chomp
+          end
+        end
+
+        # This takes any path and converts it from a Windows path to a
+        # msys style path.
+        #
+        # @param [String] path
+        # @return [String]
+        def msys_path(path)
+          begin
+            # We have to revert to the old env
+            # path here, otherwise it looks like
+            # msys2 ends up using the wrong cygpath
+            # binary and ends up with a `/cygdrive`
+            # when it doesn't exist in msys2
+            original_path_env = ENV['PATH']
+            ENV['PATH'] = ENV['VAGRANT_OLD_ENV_PATH']
+            cygwin_path(path)
           ensure
             ENV['PATH'] = original_path_env
           end
         end
 
-        # Identical to cygwin_path for now
-        alias_method :msys_path, :cygwin_path
-
         # This takes any path and converts it to a full-length Windows
         # path on Windows machines in Cygwin.
         #

test/unit/vagrant/util/platform_test.rb

@@ -22,10 +22,36 @@ describe Vagrant::Util::Platform do
       allow(Vagrant::Util::Which).to receive(:which).and_return("C:/msys2/cygpath")
       allow(Vagrant::Util::Subprocess).to receive(:execute).and_return(subprocess_result)
 
+      expect(Vagrant::Util::Subprocess).to receive(:execute).with("C:\\msys2\\cygpath", "-u", "-a", "C:\\msys2\\home\\vagrant")
+
       expect(subject.cygwin_path(path)).to eq("/home/vagrant")
     end
   end
 
+  describe "#msys_path" do
+    let(:updated_path) { "/home/vagrant" }
+    let(:subprocess_result) do
+      double("subprocess_result").tap do |result|
+        allow(result).to receive(:exit_code).and_return(0)
+        allow(result).to receive(:stdout).and_return(updated_path)
+      end
+    end
+    let(:old_path) { "/old/path/bin:/usr/local/bin:/usr/bin" }
+
+    it "takes a windows path and returns a formatted path" do
+      path = ENV["PATH"]
+      allow(Vagrant::Util::Which).to receive(:which).and_return("C:/msys2/cygpath")
+      allow(Vagrant::Util::Subprocess).to receive(:execute).and_return(subprocess_result)
+      allow(ENV).to receive(:[]).with("PATH").and_return(path)
+      allow(ENV).to receive(:[]).with("VAGRANT_OLD_ENV_PATH").and_return(old_path)
+
+      expect(Vagrant::Util::Subprocess).to receive(:execute).with("C:\\msys2\\cygpath", "-u", "-a", path)
+
+      expect(subject.msys_path(path)).to eq("/home/vagrant")
+      expect(ENV["PATH"]).to eq(path)
+    end
+  end
+
   describe "#cygwin?" do
     before do
       allow(subject).to receive(:platform).and_return("test")