From 1296a12a6d1cad13549d52e18d33bc1338ac508f Mon Sep 17 00:00:00 2001
From: Sebastian Serth <Sebastian.Serth@hpi.de>
Date: Fri, 23 Jun 2023 22:19:49 +0200
Subject: [PATCH] Language Selector: Prevent duplicate `locale=` keys

---
 app/helpers/authenticated_url_helper.rb       |  2 +-
 spec/helpers/authenticated_url_helper_spec.rb | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 spec/helpers/authenticated_url_helper_spec.rb

diff --git a/app/helpers/authenticated_url_helper.rb b/app/helpers/authenticated_url_helper.rb
index f549db09..d33d852e 100644
--- a/app/helpers/authenticated_url_helper.rb
+++ b/app/helpers/authenticated_url_helper.rb
@@ -86,7 +86,7 @@ module AuthenticatedUrlHelper
       parsed_url = URI.parse url
 
       # Add the given parameters to the query string
-      query_params = CGI.parse(parsed_url.query || '')
+      query_params = CGI.parse(parsed_url.query || '').with_indifferent_access
       query_params.merge!(parameters)
 
       # Add the query string back to the URL
diff --git a/spec/helpers/authenticated_url_helper_spec.rb b/spec/helpers/authenticated_url_helper_spec.rb
new file mode 100644
index 00000000..bc172032
--- /dev/null
+++ b/spec/helpers/authenticated_url_helper_spec.rb
@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe AuthenticatedUrlHelper do
+  describe '#add_query_parameters' do
+    it 'adds the given parameters to the given url' do
+      expect(described_class.add_query_parameters(root_url, {foo: 'bar'})).to eq(root_url(foo: 'bar'))
+    end
+
+    it 'does not duplicate existing parameters' do
+      expect(described_class.add_query_parameters(root_url(foo: 'bar'), {foo: 'baz'})).to eq(root_url(foo: 'baz'))
+    end
+  end
+end