Keep correct domain for redirects

The function redirect_filename always inserted the *.readthedocs.org
subdomain. We let this function only return the path and re-use the domain
used for the current request to build the redirect path.

Related readthedocs#1025.

readthedocs/redirects/utils.py

@@ -12,8 +12,7 @@
 
 def redirect_filename(project, filename=None):
     """
-    Return a url for a page. Always use http for now,
-    to avoid content warnings.
+    Return a path for a page. No protocol/domain is returned.
     """
     protocol = "http"
     # Handle explicit http redirects
@@ -24,19 +23,9 @@ def redirect_filename(project, filename=None):
     use_subdomain = getattr(settings, 'USE_SUBDOMAIN', False)
     if use_subdomain:
         if project.single_version:
-            return "%s://%s/%s" % (
-                protocol,
-                project.subdomain,
-                filename,
-            )
+            return "/%s" % (filename,)
         else:
-            return "%s://%s/%s/%s/%s" % (
-                protocol,
-                project.subdomain,
-                lang,
-                version,
-                filename,
-            )
+            return "/%s/%s/%s" % (lang, version, filename,)
     else:
         if project.single_version:
             return reverse('docs_detail', kwargs={
@@ -53,6 +42,10 @@ def redirect_filename(project, filename=None):
 
 
 def get_redirect_url(project, path):
+    """
+    Redirect the given path for the given project. Will always return absolute
+    paths, without domain.
+    """
     for project_redirect in project.redirects.all():
         if project_redirect.redirect_type == 'prefix':
             if path.startswith(project_redirect.from_url):
@@ -108,6 +101,9 @@ def get_redirect_response(request, full_path=None):
 
     if project:
         new_path = get_redirect_url(project, full_path)
-        if not new_path is not None:
+        if new_path is not None:
+            # Re-use the domain and protocol used in the current request.
+            # Redirects shouldn't change the domain, version or language.
+            new_path = request.build_absolute_uri(new_path)
             return HttpResponseRedirect(new_path)
     return None

readthedocs/rtd_tests/tests/test_redirects.py

@@ -217,6 +217,19 @@ def test_redirect_page(self):
         self.assertEqual(
             r['Location'], 'http://pip.readthedocs.org/en/latest/tutorial/install.html')
 
+    @override_settings(USE_SUBDOMAIN=True)
+    def test_redirect_recognizes_custom_cname(self):
+        Redirect.objects.create(
+            project=self.pip, redirect_type='page', from_url='/install.html',
+            to_url='/tutorial/install.html')
+        r = self.client.get('/install.html',
+                            HTTP_HOST='pip.pypa.io',
+                            HTTP_X_RTD_SLUG='pip')
+        self.assertEqual(r.status_code, 302)
+        self.assertEqual(
+            r['Location'],
+            'http://pip.pypa.io/en/latest/tutorial/install.html')
+
     @override_settings(USE_SUBDOMAIN=True, PYTHON_MEDIA=True)
     def test_redirect_html(self):
         Redirect.objects.create(

readthedocs/rtd_tests/tests/test_redirects_utils.py

@@ -30,7 +30,7 @@ def test_redirects_no_subdomain(self):
     def test_redirects_with_subdomain(self):
         self.assertEqual(
             redirect_filename(self.proj, 'faq.html'),
-            'http://read-the-docs.rtfd.org/en/latest/faq.html'
+            '/en/latest/faq.html'
         )
 
     @override_settings(
@@ -40,7 +40,7 @@ def test_single_version_with_subdomain(self):
         self.proj.single_version = True
         self.assertEqual(
             redirect_filename(self.proj, 'faq.html'),
-            'http://read-the-docs.rtfd.org/faq.html'
+            '/faq.html'
         )
 
     def test_single_version_no_subdomain(self):