Use safe_glob to unsafe glob

lib/jekyll/cleaner.rb

@@ -36,18 +36,13 @@ module Jekyll
     #
     # Returns a Set with the file paths
     def existing_files
-      return Set.new unless Dir.exist?(site.in_dest_dir)
-
       files = Set.new
       regex = keep_file_regex
       dirs = keep_dirs
 
-      Dir.chdir(site.in_dest_dir) do
-        Dir.glob("**/*", File::FNM_DOTMATCH).each do |f|
-          file = File.join(site.in_dest_dir, f)
-          next if file =~ HIDDEN_FILE_REGEX || file =~ regex || dirs.include?(file)
-          files << file
-        end
+      Utils.safe_glob(site.in_dest_dir, "**/*", File::FNM_DOTMATCH).each do |file|
+        next if file =~ HIDDEN_FILE_REGEX || file =~ regex || dirs.include?(file)
+        files << file
       end
 
       files

lib/jekyll/collection.rb

@@ -74,11 +74,8 @@ module Jekyll
     def entries
       return Array.new unless exists?
       @entries ||=
-        Dir.chdir(collection_dir) do
-          Dir.glob("**/*.*").map do |f|
-            entry = collection_dir(f)
-            entry["#{collection_dir}/"] = ''; entry
-          end
+        Utils.safe_glob(collection_dir, "**/*.*").map do |entry|
+          entry["#{collection_dir}/"] = ''; entry
         end
     end