change FileUtils.rm_rf -> Util.rm_rf

since the one in FileUtils is broken, or at least does not
work like the command "rm -rf". A post condition should be that
the directory does not exist OR an exception is thrown at failure.

lib/cmdtest/testcase.rb

@@ -178,7 +178,7 @@ module Cmdtest
     #------------------------------
 
     def remove_file_tree(filename)
-      FileUtils.rm_rf(_cwd_path(filename))
+      Util.rm_rf(_cwd_path(filename))
     end
 
     #------------------------------

lib/cmdtest/util.rb

@@ -19,6 +19,8 @@
 # along with "cmdtest".  If not, see <http://www.gnu.org/licenses/>.
 #----------------------------------------------------------------------
 
+require "fileutils"
+
 module Cmdtest
   class Util
 
@@ -62,5 +64,11 @@ module Cmdtest
       RUBY_PLATFORM =~ /mswin32|mingw32/
     end
 
+    def self.rm_rf(path)
+      if File.exist?(path)
+        FileUtils.rm_r(path) # exception if failing
+      end
+    end
+
   end
 end

lib/cmdtest/workdir.rb

@@ -35,8 +35,8 @@ module Cmdtest
       @runner = runner
       @path = @runner.tmp_work_dir
       @hardlinkdir = File.join(@runner.tmp_dir, "hardlinks")
-      FileUtils.rm_rf(@path)
-      FileUtils.rm_rf(@hardlinkdir)
+      Util.rm_rf(@path)
+      Util.rm_rf(@hardlinkdir)
       FileUtils.mkdir_p(@path)
       @ignored_files = []
     end