From 75c7025098750477d0447e1b434590c770b9e0bd Mon Sep 17 00:00:00 2001
From: Manfred Stienstra <manfred@fngtps.com>
Date: Mon, 21 Sep 2009 14:24:50 +0200
Subject: [PATCH] Prefix Internet Explorer's accepted mime types with sensible defaults.

---
 actionpack/lib/action_controller/request.rb |   15 ++++++++--
 actionpack/test/controller/request_test.rb  |   37 +++++++++++++++++++++++++++
 2 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/actionpack/lib/action_controller/request.rb b/actionpack/lib/action_controller/request.rb
index 1c3c1c8..a5fe383 100755
--- a/actionpack/lib/action_controller/request.rb
+++ b/actionpack/lib/action_controller/request.rb
@@ -99,7 +99,15 @@ module ActionController
       content_type.to_s
     end
 
-    # Returns the accepted MIME type for the request.
+    # Regular expression to match the Internet Explorer user agent string.
+    INTERNET_EXPLORER = /MSIE\s[\d\.]+;/
+
+    # Returns true if the user agent is Internet Explorer.
+    def internet_explorer?
+      user_agent =~ INTERNET_EXPLORER
+    end
+
+    # Returns the accepted MIME types for the request.
     def accepts
       @accepts ||= begin
         header = @env['HTTP_ACCEPT'].to_s.strip
@@ -107,7 +115,9 @@ module ActionController
         if header.empty?
           [content_type, Mime::ALL].compact
         else
-          Mime::Type.parse(header)
+          accepts = Mime::Type.parse(header)
+          accepts.unshift(Mime::HTML, Mime::XML) if internet_explorer?
+          accepts
         end
       end
     end
@@ -164,7 +174,6 @@ module ActionController
         end
     end
 
-
     # Sets the \format by string extension, which can be used to force custom formats
     # that are not controlled by the extension.
     #
diff --git a/actionpack/test/controller/request_test.rb b/actionpack/test/controller/request_test.rb
index c4cc63e..b41224a 100644
--- a/actionpack/test/controller/request_test.rb
+++ b/actionpack/test/controller/request_test.rb
@@ -371,6 +371,43 @@ class RequestTest < ActiveSupport::TestCase
     assert_equal Mime::XML, request.content_type
   end
 
+  def test_internet_explorer_user_agent_check
+    assert([
+      "curl 7.16.1 (i386-portbld-freebsd6.2) libcurl/7.16.1 OpenSSL/0.9.7m zlib/1.2.3",
+      "Opera/9.80 (Macintosh; Intel Mac OS X; U; en) Presto/2.2.15 Version/10.00",
+      "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_1; en-us) AppleWebKit/531.9 (KHTML, like Gecko) Version/4.0.3 Safari/531.9",
+      "Mozilla/5.0 (Macintosh; U; Intel Mac OS X; en; rv:1.8.1.23) Gecko/20090815 Camino/1.6.9 (like Firefox/2.0.0.23)",
+      "Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.1) Gecko/20090624 Firefox/3.5"
+    ].all? do |user_agent| 
+      !stub_request('HTTP_USER_AGENT' => user_agent).internet_explorer?
+    end)
+
+    assert([
+      "Mozilla/4.0 (Windows; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 2.0.50727)",
+      "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; )",
+      "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Win64; x64; Trident/4.0)"
+    ].all? do |user_agent|
+      stub_request('HTTP_USER_AGENT' => user_agent).internet_explorer?
+    end)
+  end
+
+  def test_accepts_without_user_agent
+    request = stub_request 'HTTP_ACCEPT' => 'text/html, text/csv, */*'
+    assert_equal [Mime::HTML, Mime::CSV, Mime::ALL], request.accepts
+  end
+
+  def test_accepts_for_regular_user_agent
+    request = stub_request 'HTTP_USER_AGENT' => "curl 7.16.1 (i386-portbld-freebsd6.2) libcurl/7.16.1 OpenSSL/0.9.7m zlib/1.2.3", 'HTTP_ACCEPT' => 'text/html, text/csv, */*'
+    assert_equal [Mime::HTML, Mime::CSV, Mime::ALL], request.accepts
+  end
+
+  def test_accepts_for_internet_explorer
+    request = stub_request 'HTTP_USER_AGENT' => 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0; Win64; x64)',
+      'HTTP_ACCEPT' => "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/x-shockwave-flash, application/x-silverlight, */*"
+    assert_equal 16, request.accepts.length
+    assert_equal [Mime::HTML, Mime::XML], request.accepts[0..1]
+  end
+
   def test_user_agent
     request = stub_request 'HTTP_USER_AGENT' => 'TestAgent'
     assert_equal 'TestAgent', request.user_agent
-- 
1.6.4.2