From 952504e76c285e27e062cc0e2b4cefa54b0db59a Mon Sep 17 00:00:00 2001
From: Ivo Branco <ivo.branco@fccn.pt>
Date: Wed, 25 Jan 2023 12:05:45 +0000
Subject: [PATCH] feat: add setting so redirect preserve params

Added a new setting that allow to configure globally if the django-cms
redirects preserving the query parameters.
`REDIRECT_PRESERVE_QUERY_PARAMS`.
This feature is usefull for example:
1. marketing campains extra parameters,
2. social networks extra parameters like `fbclick`,
3. custom developed parameters, after that page has been moved, the
older URLs for that page should preserve the functionality.
---
 cms/tests/test_views.py          | 25 +++++++++++++++++++++++++
 cms/utils/conf.py                |  1 +
 cms/views.py                     |  4 ++++
 docs/reference/configuration.rst | 10 ++++++++++
 4 files changed, 40 insertions(+)

diff --git a/cms/tests/test_views.py b/cms/tests/test_views.py
index b90725743b2..9d80d20d6ad 100644
--- a/cms/tests/test_views.py
+++ b/cms/tests/test_views.py
@@ -152,6 +152,31 @@ def test_redirect_with_toolbar(self):
             response = self.client.get(self.get_toolbar_disable_url(page_url))
             self.assertEqual(response.status_code, 302)
 
+    def test_redirect_not_preserving_query_parameters(self):
+        # test redirect checking that the query parameters aren't preserved
+        redirect = '/en/'
+        one = create_page("one", "nav_playground.html", "en", published=True,
+                          redirect=redirect)
+        url = one.get_absolute_url()
+        params = "?param_name=param_value"
+        request = self.get_request(url + params)
+        response = details(request, one.get_path())
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response['Location'], redirect)
+
+    @override_settings(CMS_REDIRECT_PRESERVE_QUERY_PARAMS=True)
+    def test_redirect_preserving_query_parameters(self):
+        # test redirect checking that query parameters are preserved
+        redirect = '/en/'
+        one = create_page("one", "nav_playground.html", "en", published=True,
+                          redirect=redirect)
+        url = one.get_absolute_url()
+        params = "?param_name=param_value"
+        request = self.get_request(url + params)
+        response = details(request, one.get_path())
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response['Location'], redirect + params)
+
     def test_login_required(self):
         self.create_homepage("page", "nav_playground.html", "en", published=True, login_required=True)
         plain_url = '/accounts/'
diff --git a/cms/utils/conf.py b/cms/utils/conf.py
index 22b33b5a726..d3863f3a4ac 100644
--- a/cms/utils/conf.py
+++ b/cms/utils/conf.py
@@ -89,6 +89,7 @@ def wrapper():
     ),
     'COLOR_SCHEME': 'light',
     'COLOR_SCHEME_TOGGLE': False,
+    'REDIRECT_PRESERVE_QUERY_PARAMS': False,
 }
 
 
diff --git a/cms/views.py b/cms/views.py
index 6343ae2bf59..89c80c377b7 100644
--- a/cms/views.py
+++ b/cms/views.py
@@ -162,6 +162,10 @@ def details(request, slug):
             toolbar.redirect_url = redirect_url
         elif redirect_url not in own_urls:
             # prevent redirect to self
+            if get_cms_setting('REDIRECT_PRESERVE_QUERY_PARAMS'):
+                query_string = request.META.get('QUERY_STRING')
+                if query_string:
+                    redirect_url += "?" + query_string
             return HttpResponseRedirect(redirect_url)
 
     # permission checks
diff --git a/docs/reference/configuration.rst b/docs/reference/configuration.rst
index 08d0ff1301b..a630c28d2fd 100644
--- a/docs/reference/configuration.rst
+++ b/docs/reference/configuration.rst
@@ -1190,3 +1190,13 @@ when the "Content" field is filled in. There should be no need to change it,
 unless you **don't** use ``djangocms-text-ckeditor`` in your project **and**
 your custom plugin defined in :setting:`CMS_PAGE_WIZARD_CONTENT_PLUGIN` have a
 body field **different** than ``body``.
+
+..  setting:: CMS_REDIRECT_PRESERVE_QUERY_PARAMS
+
+CMS_REDIRECT_PRESERVE_QUERY_PARAMS
+===================================
+
+default
+    ``False``
+
+This indicates to the CMS that redirects should preserve the query parameters.