Avoid using Dir.glob with absolute path

the absolute path including '[', '{', '?', or '*'
could change the outcome

lib/jekyll/cleaner.rb

@@ -36,14 +36,19 @@ 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.glob(site.in_dest_dir("**", "*"), File::FNM_DOTMATCH) do |file|
+      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
+      end
 
       files
     end

lib/jekyll/collection.rb

@@ -74,10 +74,13 @@ module Jekyll
     def entries
       return Array.new unless exists?
       @entries ||=
-        Dir.glob(collection_dir("**", "*.*")).map do |entry|
+        Dir.chdir(collection_dir) do
+          Dir.glob("**/*.*").map do |f|
+            entry = collection_dir(f)
             entry["#{collection_dir}/"] = ''; entry
           end
         end
+    end
 
     # Filtered version of the entries in this collection.
     # See `Jekyll::EntryFilter#filter` for more information.