Keep GET params in return URL

When signing in from a page containing GET params, like
`/budgets/1/investments?heading_id=4`, we were redirected to a URL
without those GET params; in this case, `/budgets/1/investments`.

Using the request fullpath, as recommended in the devise documentation,
keeps these parameters when redirecting.

app/controllers/application_controller.rb

@@ -108,7 +108,7 @@ class ApplicationController < ActionController::Base
 
     def set_return_url
       if !devise_controller? && controller_name != "welcome" && is_navigational_format?
-        store_location_for(:user, request.path)
+        store_location_for(:user, request.fullpath)
       end
     end
 

spec/system/sessions_spec.rb

@@ -17,4 +17,17 @@ describe "Sessions" do
     expect(page).to have_content("You have been signed out successfully")
     expect(page).to have_current_path(debate_path(debate))
   end
+
+  scenario "Sign in redirects keeping GET parameters" do
+    create(:user, :level_two, email: "dev@consul.dev", password: "consuldev")
+    heading = create(:budget_heading, name: "outskirts")
+
+    visit budget_investments_path(heading.budget, heading_id: "outskirts")
+    click_link "Sign in"
+    fill_in "user_login",    with: "dev@consul.dev"
+    fill_in "user_password", with: "consuldev"
+    click_button "Enter"
+
+    expect(page).to have_current_path budget_investments_path(heading.budget, heading_id: "outskirts")
+  end
 end