rm homebrew-fork extend Pathname#rmdir_if_possible

integrate a modified version into our codebase as a utility
method (no longer a monkeypatch)

lib/cask/installer.rb

@@ -316,15 +316,11 @@ class Cask::Installer
         permissions_rmtree subdir unless PERSISTENT_METADATA_SUBDIRS.include?(subdir.basename)
       end
     end
-    if @cask.metadata_versioned_container_path.respond_to?(:rmdir_if_possible)
-      @cask.metadata_versioned_container_path.rmdir_if_possible
-    end
-    if @cask.metadata_master_container_path.respond_to?(:rmdir_if_possible)
-      @cask.metadata_master_container_path.rmdir_if_possible
-    end
+    Cask::Utils.rmdir_if_possible(@cask.metadata_versioned_container_path)
+    Cask::Utils.rmdir_if_possible(@cask.metadata_master_container_path)
 
     # toplevel staged distribution
-    @cask.caskroom_path.rmdir_if_possible
+    Cask::Utils.rmdir_if_possible(@cask.caskroom_path)
   end
 
   def purge_caskroom_path

lib/cask/utils.rb

@@ -134,6 +134,27 @@ module Cask::Utils
     end
   end
 
+  # from Homebrew
+  # children.length == 0 is slow to enumerate the whole directory just
+  # to see if it is empty
+  def self.rmdir_if_possible(dir)
+    dirpath = Pathname(dir)
+    begin
+      dirpath.rmdir
+      true
+    rescue Errno::ENOTEMPTY
+      if (ds_store = dirpath.join('.DS_Store')).exist? and
+        dirpath.children.length == 1
+        ds_store.unlink
+        retry
+      else
+        false
+      end
+    rescue Errno::EACCES, Errno::ENOENT
+      false
+    end
+  end
+
   # paths that "look" descendant (textually) will still
   # return false unless both the given paths exist
   def self.file_is_descendant(file, dir)

lib/homebrew-fork/Library/Homebrew/extend/pathname.rb

@@ -1,22 +1,6 @@
 require 'pathname'
 
 class Pathname
-  # I don't trust the children.length == 0 check particularly, not to mention
-  # it is slow to enumerate the whole directory just to see if it is empty,
-  # instead rely on good ol' libc and the filesystem
-  def rmdir_if_possible
-    rmdir
-    true
-  rescue Errno::ENOTEMPTY
-    if (ds_store = self+'.DS_Store').exist? && children.length == 1
-      ds_store.unlink
-      retry
-    else
-      false
-    end
-  rescue Errno::EACCES, Errno::ENOENT
-    false
-  end
 
   def version
     require 'version'