Use filesystem encoding as FileHandler's encoding

instead of `@root.encoding`.
And fallback to ASCII-8BIT when filesystem encoding is US-ASCII.

When `@root.encoding` is not compatible filesystem encoding,
`Encoding::CompatibilityError` raised at `webrick/httpservlet/filehandler.rb:341`.
So `DocumentRoot` must be compatible with filesystem encoding.

2 files changed, 14 insertions, 10 deletions

diff --git a/lib/webrick/httpservlet/filehandler.rb b/lib/webrick/httpservlet/filehandler.rb
index f67d416b72..4f6fe706e2 100644
--- a/lib/webrick/httpservlet/filehandler.rb
+++ b/lib/webrick/httpservlet/filehandler.rb
@@ -212,6 +212,14 @@ module WEBrick
 
       # :stopdoc:
 
+      def set_filesystem_encoding(str)
+        if Encoding.find('filesystem') == Encoding::US_ASCII
+          str.b
+        else
+          str.dup.force_encoding('filesystem')
+        end
+      end
+
       def service(req, res)
         # if this class is mounted on "/" and /~username is requested.
         # we're going to override path information before invoking service.
@@ -325,16 +333,7 @@ module WEBrick
 
       def set_filename(req, res)
         res.filename = @root
-        path_info = req.path_info.scan(%r|/[^/]*|)
-        begin
-          path_info.map! do |path|
-            path.force_encoding('filesystem').encode(@root.encoding)
-          end
-        rescue EncodingError
-          path_info.map! do |path|
-            path.force_encoding(@root.encoding)
-          end
-        end
+        path_info = set_filesystem_encoding(req.path_info).scan(%r|/[^/]*|)
 
         path_info.unshift("")  # dummy for checking @root dir
         while base = path_info.first
diff --git a/test/webrick/test_filehandler.rb b/test/webrick/test_filehandler.rb
index 758ec7f589..d6fa4e2f15 100644
--- a/test/webrick/test_filehandler.rb
+++ b/test/webrick/test_filehandler.rb
@@ -291,6 +291,11 @@ class WEBrick::TestFileHandler < Test::Unit::TestCase
   def test_cjk_in_path
     Dir.mktmpdir("\u3042") do |dir|
       File.write("#{dir}/\u3042.txt", "test_cjk_in_path")
+      begin
+        dir = dir.encode('filesystem')
+      rescue EncodingError
+        dir = dir.b
+      end
       config = { :DocumentRoot => dir }
       TestWEBrick.start_httpserver(config) do |server, addr, port, log|
         http = Net::HTTP.new(addr, port)