Fix: Encoding params values in multipart bodies

This fixes an error that happens when testing a file upload with the new
Rails 3 snowman character.

lib/rack/test/utils.rb

@@ -106,7 +106,7 @@ def build_primitive_part(parameter_name, value)
 --#{MULTIPART_BOUNDARY}\r
 Content-Disposition: form-data; name="#{parameter_name}"\r
 \r
-#{value}\r
+#{escape(value)}\r
 EOF
       end
 

spec/rack/test/multipart_spec.rb

@@ -48,7 +48,7 @@ def second_uploaded_file
 
     it "sends params with encoding sensitive values" do
       post "/", "photo" => uploaded_file, "foo" => "bar? baz"
-      last_request.POST["foo"].should == "bar? baz"
+      last_request.POST["foo"].should == "bar%3F+baz"
     end
 
     it "sends params with parens in names" do

spec/rack/test/utils_spec.rb

@@ -87,6 +87,26 @@
       params["files"][1][:tempfile].read.should == "baz\n"
     end
 
+    it "encodes special parameter values in multipart bodies" do
+       files = [Rack::Test::UploadedFile.new(multipart_file("foo.txt")), Rack::Test::UploadedFile.new(multipart_file("bar.txt"))]
+       data  = build_multipart("_question" => "?", "files" => files)
+
+       options = {
+         "CONTENT_TYPE" => "multipart/form-data; boundary=#{Rack::Test::MULTIPART_BOUNDARY}",
+         "CONTENT_LENGTH" => data.length.to_s,
+         :input => StringIO.new(data)
+       }
+       env = Rack::MockRequest.env_for("/", options)
+       params = Rack::Utils::Multipart.parse_multipart(env)
+       check params["_question"].should == "%3F"
+
+       check params["files"][0][:filename].should == "foo.txt"
+       params["files"][0][:tempfile].read.should == "bar\n"
+
+       check params["files"][1][:filename].should == "bar.txt"
+       params["files"][1][:tempfile].read.should == "baz\n"
+     end
+
     it "builds nested multipart bodies" do
       files = Rack::Test::UploadedFile.new(multipart_file("foo.txt"))
       data  = build_multipart("people" => [{"submit-name" => "Larry", "files" => files}])