From 6b55d11c08daafc8e4ec84fb04efc29c8adc7bd8 Mon Sep 17 00:00:00 2001
From: zedshaw <zedshaw@19e92222-5c0b-0410-8929-a290d50e31e9>
Date: Tue, 24 Oct 2006 23:22:16 +0000
Subject: [PATCH] Patch #6275 for improved deflate filter support for IE and
 Safari.

git-svn-id: svn+ssh://rubyforge.org/var/svn/mongrel/trunk@366 19e92222-5c0b-0410-8929-a290d50e31e9
---
 lib/mongrel/handlers.rb | 24 ++++++++++++++++++------
 test/test_handlers.rb   | 19 ++++++++++++++++---
 2 files changed, 34 insertions(+), 9 deletions(-)

diff --git a/lib/mongrel/handlers.rb b/lib/mongrel/handlers.rb
index fb32d2e5..d19f3bba 100644
--- a/lib/mongrel/handlers.rb
+++ b/lib/mongrel/handlers.rb
@@ -282,6 +282,7 @@ module Mongrel
   # Valid option is :always_deflate => false which tells the handler to
   # deflate everything even if the client can't handle it.
   class DeflateFilter < HttpHandler
+    include Zlib
     HTTP_ACCEPT_ENCODING = "HTTP_ACCEPT_ENCODING" 
 
     def initialize(ops={})
@@ -294,14 +295,25 @@ module Mongrel
       # only process if they support compression
       if @always_deflate or (accepts and (accepts.include? "deflate" and not response.body_sent))
         response.header["Content-Encoding"] = "deflate"
-        # we can't just rewind the body and gzip it since the body could be an attached file
-        response.body.rewind
-        gzout = StringIO.new(Zlib::Deflate.deflate(response.body.read))
-        gzout.rewind
-        response.body.close
-        response.body = gzout
+        response.body = deflate(response.body)
       end
     end
+
+    private
+      def deflate(stream)
+        deflater = Deflate.new(
+          DEFAULT_COMPRESSION,
+          # drop the zlib header which causes both Safari and IE to choke
+          -MAX_WBITS, 
+          DEF_MEM_LEVEL,
+          DEFAULT_STRATEGY)
+
+        stream.rewind
+        gzout = StringIO.new(deflater.deflate(stream.read, FINISH))
+        stream.close
+        gzout.rewind
+        gzout
+      end
   end
 
 
diff --git a/test/test_handlers.rb b/test/test_handlers.rb
index 7df0f15a..98f83c08 100644
--- a/test/test_handlers.rb
+++ b/test/test_handlers.rb
@@ -45,7 +45,7 @@ class HandlersTest < Test::Unit::TestCase
         uri "/", :handler => SimpleHandler.new
         uri "/", :handler => stats
         uri "/404", :handler => Mongrel::Error404Handler.new("Not found")
-        uri "/dumb", :handler => Mongrel::DeflateFilter.new(:always_deflate => true)
+        uri "/dumb", :handler => Mongrel::DeflateFilter.new
         uri "/dumb", :handler => DumbHandler.new, :in_front => true
         uri "/files", :handler => Mongrel::DirHandler.new("doc")
         uri "/files_nodir", :handler => Mongrel::DirHandler.new("doc",listing_allowed=false, index_html="none")
@@ -73,8 +73,21 @@ class HandlersTest < Test::Unit::TestCase
     check_status res, String
   end
 
-  def test_deflate_access
-    req = Net::HTTP::Get.new("http://localhost:9998/dumb")
+  def test_deflate
+    Net::HTTP.start("localhost", 9998) do |h|
+      # test that no accept-encoding returns a non-deflated response
+      req = h.get("/dumb")
+      assert(
+        !req.header['Content-Encoding'] ||
+        !req.header['Content-Encoding'].include?('deflate'))
+      assert_equal "test", req.body
+
+      req = h.get("/dumb", {"Accept-Encoding" => "deflate"})
+      # -MAX_WBITS stops zlib from looking for a zlib header
+      inflater = Zlib::Inflate.new(-Zlib::MAX_WBITS)
+      assert req.header['Content-Encoding'].include?('deflate')
+      assert_equal "test", inflater.inflate(req.body)
+    end
   end
 
   # TODO: find out why this fails on win32 but nowhere else