base (refined) Pathname#ascendant_of? also on Pathname#ascend

A small rewrite in a last attempt at writing obvious and portable code
without manual string manipulation.

Note that Pathname#== uses string comparison on Windows, so if client
code passes "C:\foo" and "c:/foo/bar" the predicate won't see the
former is an ascendant of the latter. Risky business.

1 files changed, 2 insertions, 7 deletions

diff --git a/activesupport/lib/active_support/file_evented_update_checker.rb b/activesupport/lib/active_support/file_evented_update_checker.rb
index 5e5874c014..638458c6ce 100644
--- a/activesupport/lib/active_support/file_evented_update_checker.rb
+++ b/activesupport/lib/active_support/file_evented_update_checker.rb
@@ -79,13 +79,8 @@ module ActiveSupport
       using Module.new {
         refine Pathname do
           def ascendant_of?(other)
-            if self != other && other.to_s.start_with?(to_s)
-              # On Windows each_filename does not include the drive letter,
-              # but the test above already detects if they differ.
-              parts = each_filename.to_a
-              other_parts = other.each_filename.to_a
-
-              other_parts[0, parts.length] == parts
+            self != other && other.ascend do |ascendant|
+              break true if self == ascendant
             end
           end
         end