Fix deletion of empty directories:

1. When comparing the directory to delete against the top level
   cache_path, use File.realpath to make sure we aren't comparing two
   unequal strings that point to the same path. This occurs, for
   example, when cache_path has a trailing slash, which it does in the
   default Rails configuration. Since the input to
   delete_empty_directories never has a trailing slash, the comparison
   will never be true and the top level cache directory (and above) may
   be deleted. However…

2. File.delete raises EPERM when trying to delete a directory, so no
   directories have ever been deleted. Changing the code to Dir.delete
   fixes that.

1 files changed, 2 insertions, 2 deletions

diff --git a/activesupport/lib/active_support/cache/file_store.rb b/activesupport/lib/active_support/cache/file_store.rb
index 8e265ad863..0c55aa8a32 100644
--- a/activesupport/lib/active_support/cache/file_store.rb
+++ b/activesupport/lib/active_support/cache/file_store.rb
@@ -150,9 +150,9 @@ module ActiveSupport
 
         # Delete empty directories in the cache.
         def delete_empty_directories(dir)
-          return if dir == cache_path
+          return if File.realpath(dir) == File.realpath(cache_path)
           if Dir.entries(dir).reject {|f| EXCLUDED_DIRS.include?(f)}.empty?
-            File.delete(dir) rescue nil
+            Dir.delete(dir) rescue nil
             delete_empty_directories(File.dirname(dir))
           end
         end