Move empty hash to it's own method for session

This sets the session's default to a new method called `default_session`
which is set to an empty hash.

Now we can depend on the `default_session` method rather than depending
on the implementation of `Hash`.

2 files changed, 8 insertions, 1 deletions

diff --git a/lib/rack/request.rb b/lib/rack/request.rb
index 50dba475..a76f15cd 100644
--- a/lib/rack/request.rb
+++ b/lib/rack/request.rb
@@ -160,7 +160,7 @@ module Rack
 
       def session
         fetch_header(RACK_SESSION) do |k|
-          set_header RACK_SESSION, {}
+          set_header RACK_SESSION, default_session
         end
       end
 
@@ -439,6 +439,8 @@ module Rack
 
       private
 
+      def default_session; {}; end
+
       def parse_http_accept_header(header)
         header.to_s.split(/\s*,\s*/).map do |part|
           attribute, parameters = part.split(/\s*;\s*/, 2)
diff --git a/test/spec_request.rb b/test/spec_request.rb
index 2062e246..74f2fa87 100644
--- a/test/spec_request.rb
+++ b/test/spec_request.rb
@@ -1305,6 +1305,11 @@ EOF
     req.trusted_proxy?("2001:470:1f0b:18f8::1").must_equal nil
   end
 
+  it "sets the default session to an empty hash" do
+    req = make_request(Rack::MockRequest.env_for("http://example.com:8080/"))
+    assert_equal Hash.new, req.session
+  end
+
   class MyRequest < Rack::Request
     def params
       {:foo => "bar"}