WEBrick::HTTPResponse create tempfile if required.

WEBrick::HTTPProxyServer implementes HTTP proxy using
WEBrick and Net::HTTP.
WEBrick accepts HTTP/1.0 clients and
Net::HTTP uses always HTTP/1.1.

However HTTP/1.1 supports chunked transfer coding HTTP/1.0 doesn't.

Chunked transfer coding doesn't require that
content-length before the content is sent.
But non-chunked transfer coding require content-length before
the content is sent.

So, when HTTP/1.0 clients connects WEBrick::HTTPProxyServer and
origin server returns chunked response,
WEBrick::HTTPProxyServer needs to store whole content to
know the length of it.

This patch do it using tempfile.

lib/webrick/httpresponse.rb

@@ -113,6 +113,7 @@ module WEBrick
       @chunked = false
       @filename = nil
       @sent_size = 0
+      @bodytempfile = nil
     end
 
     ##
@@ -253,7 +254,10 @@ module WEBrick
       elsif %r{^multipart/byteranges} =~ @header['content-type']
         @header.delete('content-length')
       elsif @header['content-length'].nil?
-        unless @body.is_a?(IO)
+        if @body.respond_to? :readpartial
+        elsif @body.respond_to? :call
+          make_body_tempfile
+        else
           @header['content-length'] = (@body ? @body.bytesize : 0).to_s
         end
       end
@@ -282,6 +286,33 @@ module WEBrick
       end
     end
 
+    def make_body_tempfile # :nodoc:
+      return if @bodytempfile
+      bodytempfile = Tempfile.create("webrick")
+      if @body.nil?
+        # nothing
+      elsif @body.respond_to? :readpartial
+        IO.copy_stream(@body, bodytempfile)
+        @body.close
+      elsif @body.respond_to? :call
+        @body.call(bodytempfile)
+      else
+        bodytempfile.write @body
+      end
+      bodytempfile.rewind
+      @body = @bodytempfile = bodytempfile
+      @header['content-length'] = bodytempfile.stat.size.to_s
+    end
+
+    def remove_body_tempfile # :nodoc:
+      if @bodytempfile
+        @bodytempfile.close
+        File.unlink @bodytempfile.path
+        @bodytempfile = nil
+      end
+    end
+
+
     ##
     # Sends the headers on +socket+
 
@@ -445,6 +476,7 @@ module WEBrick
       ensure
         @body.close
       end
+      remove_body_tempfile
     end
 
     def send_body_string(socket)
@@ -477,7 +509,12 @@ module WEBrick
         socket.write("0#{CRLF}#{CRLF}")
       else
         size = @header['content-length'].to_i
-        @body.call(socket)
+        if @bodytempfile
+          @bodytempfile.rewind
+          IO.copy_stream(@bodytempfile, socket)
+        else
+          @body.call(socket)
+        end
         @sent_size = size
       end
     end

test/webrick/test_httpproxy.rb

@@ -215,6 +215,46 @@ class TestWEBrickHTTPProxy < Test::Unit::TestCase
     end
   end
 
+  def test_http10_proxy_chunked
+    # Testing HTTP/1.0 client request and HTTP/1.1 chunked response
+    # from origin server.
+    #                    +------+
+    #                    V      |
+    #  client -------> proxy ---+
+    #           GET          GET
+    #           HTTP/1.0     HTTP/1.1
+    #           non-chunked  chunked
+    #
+    proxy_handler_called = request_handler_called = 0
+    config = {
+      :ServerName => "localhost.localdomain",
+      :ProxyContentHandler => Proc.new{|req, res| proxy_handler_called += 1 },
+      :RequestCallback => Proc.new{|req, res| request_handler_called += 1 }
+    }
+    log_tester = lambda {|log, access_log|
+      log.reject! {|str|
+        %r{WARN  chunked is set for an HTTP/1\.0 request\. \(ignored\)} =~ str
+      }
+      assert_equal([], log)
+    }
+    TestWEBrick.start_httpproxy(config, log_tester){|server, addr, port, log|
+      body = nil
+      server.mount_proc("/"){|req, res|
+        body = "#{req.request_method} #{req.path} #{req.body}"
+        res.chunked = true
+        res.body = -> (socket) { body.each_char {|c| socket.write c } }
+      }
+      http = Net::HTTP.new(addr, port, addr, port)
+
+      # Don't use Net::HTTP because it uses HTTP/1.1.
+      TCPSocket.open(addr, port) {|s|
+        s.write "GET / HTTP/1.0\r\nHost: localhost.localdomain\r\n\r\n"
+        response = s.read
+        assert_equal(body, response[/.*\z/])
+      }
+    }
+  end
+
   def make_certificate(key, cn)
     subject = OpenSSL::X509::Name.parse("/DC=org/DC=ruby-lang/CN=#{cn}")
     exts = [