Add more referer tests

This includes a pending test "should send no referer when visiting a
second page", which does not pass on Rack::Test right now.

lib/capybara/spec/driver.rb

@@ -297,9 +297,33 @@ shared_examples_for "driver with infinite redirect detection" do
 end
 
 shared_examples_for "driver with referer support" do
+  before :each do
+    @driver.reset!
+  end
+
+  it "should send no referer when visiting a page" do
+    @driver.visit '/get_referer'
+    @driver.body.should include 'No referer'
+  end
+
+  it "should send no referer when visiting a second page" do
+    if @driver.is_a? Capybara::RackTest::Driver
+      pending 'Rack::Test sends referer on subsequent visit'
+    end
+    @driver.visit '/get_referer'
+    @driver.visit '/get_referer'
+    @driver.body.should include 'No referer'
+  end
+
+  it "should send a referer when following a link" do
+    @driver.visit '/referer_base'
+    @driver.find('//a[@href="/get_referer"]').first.click
+    @driver.body.should include '/referer_base'
+  end
+
   it "should preserve the original referer URL when following a redirect" do
     @driver.visit('/referer_base')
-    @driver.find('//a[@href="redirect_and_keep_referer"]').first.click
-    @driver.body.should include('referer_base')
+    @driver.find('//a[@href="/redirect_to_get_referer"]').first.click
+    @driver.body.should include('/referer_base')
   end
 end

lib/capybara/spec/test_app.rb

@@ -25,15 +25,15 @@ class TestApp < Sinatra::Base
   end
 
   get '/referer_base' do
-    'Referer base: <a href="redirect_and_keep_referer">Link that will redirect</a>'
+    '<a href="/get_referer">direct link</a>; <a href="/redirect_to_get_referer">link via redirect</a>'
   end
 
-  get '/redirect_and_keep_referer' do
+  get '/redirect_to_get_referer' do
     redirect '/get_referer'
   end
 
   get '/get_referer' do
-    'Got referer: ' + request.referer
+    request.referer.nil? ? "No referer" : "Got referer: #{request.referer}"
   end
 
   get '/host' do