Fix problem where capybara can't post to relative urls in form actions.

lib/capybara/rack_test/browser.rb

@@ -35,13 +35,16 @@ class Capybara::RackTest::Browser
     new_uri = URI.parse(path)
     current_uri = URI.parse(current_url)
 
-    path = request_path + path if path.start_with?('?')
-    path = current_host + path if path.start_with?('/')
-
     if new_uri.host
       @current_host = new_uri.scheme + '://' + new_uri.host
     end
-
+    
+    unless new_uri.absolute?
+      path = request_path + path if path.start_with?('?')
+      path = request_path + '/' + path unless path.start_with?('/')
+      path = current_host + path
+    end
+    
     reset_cache!
     send(method, path, attributes, env)
     follow_redirects!

lib/capybara/spec/session/click_button_spec.rb

@@ -12,6 +12,14 @@ shared_examples_for "click_button" do
       end
     end
 
+    context "with a form that has a relative url as an action" do
+      it "should post to the correct url" do
+        @session.click_button('Relative Action')
+        @session.current_path.should == '/form/relative'
+        extract_results(@session)['relative'].should == 'Relative Action'
+      end
+    end
+
     context "with value given on a submit button" do
       context "on a form with HTML5 fields" do
         before do
@@ -284,4 +292,5 @@ shared_examples_for "click_button" do
       @session.body.should include('Postback')
     end
   end
+
 end

lib/capybara/spec/test_app.rb

@@ -47,6 +47,10 @@ class TestApp < Sinatra::Base
     '<pre id="results">' + params[:form].to_yaml + '</pre>'
   end
 
+  post '/form/relative' do
+    '<pre id="results">' + params[:form].to_yaml + '</pre>'
+  end
+
   get '/favicon.ico' do
     nil
   end

lib/capybara/spec/views/form.erb

@@ -351,3 +351,9 @@
     <input type="submit" name="form[button]" value="Just a button"/>
   </p>
 </form>
+
+<form action="relative" method="post">
+  <p>
+    <input type="submit" name="form[relative]" value="Relative Action" />
+  </p>
+</form>