(PUP-5018) Cannot unlink dangling Windows symlinks

 - When a symlink is created to point at a directory, then that target
   directory is removed, Windows was previously generating
   `Errno::EACCES: Permission denied @ unlink_internal` because the
   underlying Ruby File.unlink was being called, which fails on Windows.

   When the target no longer exists, Ruby's File.unlink only works
   properly on symlinks pointed at files and not symlinks pointed at
   directories.

   Given the lstat only specifies 'link' and does not describe the
   target, there is no way of knowing whether the former target was a
   file or directory.  Thefore, when the target stat does not exist,
   first attempt to File.unlink, and if that fails call Dir.rmdir.
   Ruby's Dir.rmdir only works on links that were targeted at
   directories, and not links that were targeted at files.

lib/puppet/file_system/windows.rb

@@ -62,7 +62,9 @@ def unlink(*file_names)
       stat = Puppet::Util::Windows::File.stat(file_name) rescue nil
 
       # sigh, Ruby + Windows :(
-      if stat && stat.ftype == 'directory'
+      if !stat
+        ::File.unlink(file_name) rescue Dir.rmdir(file_name)
+      elsif stat.ftype == 'directory'
         if Puppet::Util::Windows::File.symlink?(file_name)
           Dir.rmdir(file_name)
         else

spec/unit/file_system_spec.rb

@@ -446,6 +446,26 @@ def increment_counter_in_multiple_processes(file, num_procs, options)
       expect(Puppet::FileSystem.readlink(symlink)).to eq(missing_file.to_s)
     end
 
+    it "should be able to unlink a dangling symlink pointed at a file" do
+      symlink = tmpfile("somefile_link")
+      Puppet::FileSystem.symlink(file, symlink)
+      ::File.delete(file)
+      Puppet::FileSystem.unlink(symlink)
+
+      expect(Puppet::FileSystem).to_not be_exist(file)
+      expect(Puppet::FileSystem).to_not be_exist(symlink)
+    end
+
+    it "should be able to unlink a dangling symlink pointed at a directory" do
+      symlink = tmpfile("somedir_link")
+      Puppet::FileSystem.symlink(dir, symlink)
+      Dir.rmdir(dir)
+      Puppet::FileSystem.unlink(symlink)
+
+      expect(Puppet::FileSystem).to_not be_exist(dir)
+      expect(Puppet::FileSystem).to_not be_exist(symlink)
+    end
+
     it "should delete only the symlink and not the target when calling unlink instance method" do
       [file, dir].each do |target|
         symlink = tmpfile("#{Puppet::FileSystem.basename(target)}_link")