manager: add validation of redirect url template syntax (#55363)

combo/manager/forms.py

@@ -20,6 +20,7 @@ from django import forms
 from django.conf import settings
 from django.contrib.auth.models import Group
 from django.core.exceptions import ValidationError
+from django.template import Template, TemplateSyntaxError
 from django.template.loader import TemplateDoesNotExist, get_template
 from django.utils.translation import ugettext_lazy as _
 
@@ -175,6 +176,15 @@ class PageEditRedirectionForm(forms.ModelForm):
         model = Page
         fields = ('redirect_url',)
 
+    def clean_redirect_url(self):
+        value = self.cleaned_data.get('redirect_url')
+        if value:
+            try:
+                Template(value)
+            except TemplateSyntaxError as e:
+                raise ValidationError(_('syntax error: %s') % e)
+        return value
+
     def save(self, *args, **kwargs):
         page = super(PageEditRedirectionForm, self).save(*args, **kwargs)
         page.redirect_url = page.redirect_url.strip()

tests/test_manager.py

@@ -278,6 +278,12 @@ def test_edit_page(app, admin_user):
     resp = resp.follow()
     assert 'http://www.example.net' in resp.text
     assert Page.objects.all()[0].redirect_url == 'http://www.example.net'
+    # redirection (error handling)
+    resp = resp.click(href='.*/redirection')
+    resp.form['redirect_url'].value = '{{ foo bar }}'
+    resp = resp.form.submit()
+    assert 'syntax error:' in resp.text
+    resp = resp.click('Cancel')
     # exclude from nav
     resp = resp.click(href='.*/include-in-navigation')
     resp.form['include_in_navigation'].checked = False