Much clearer query
@@ -511,7 +511,7 @@ class TranslationForm(forms.Form):
translation_project_slug = self.cleaned_data['project']
# Ensure parent project isn't already itself a translation
- if Project.objects.filter(translations__in=[self.parent]).exists():
+ if self.parent.main_language_project is not None:
msg = 'Project "{}" is already a translation'
raise forms.ValidationError(
(_(msg).format(self.parent.slug))
