load session data for merge!

ID#prepare_session calls merge! on the newly-created SessionHash, but
this method is not overridden to parse existing data. As such, any
previous session data passed in from an earlier middleware is discarded.

For me, this was breaking Rack::Test while testing a Sinatra app.

1 files changed, 7 insertions, 0 deletions

diff --git a/test/spec_session_cookie.rb b/test/spec_session_cookie.rb
index 66490b53..e325584d 100644
--- a/test/spec_session_cookie.rb
+++ b/test/spec_session_cookie.rb
@@ -338,4 +338,11 @@ describe Rack::Session::Cookie do
     response = response_for(:app => session_id, :request => request)
     response.body.should.match(/foo/)
   end
+
+  it "allows modifying session data with session data from middleware in front" do
+    request = { 'rack.session' => { :foo => 'bar' }}
+    response = response_for(:app => incrementor, :request => request)
+    response.body.should.match(/counter/)
+    response.body.should.match(/foo/)
+  end
 end