Check for existing liaison titles. Fixes ietf-tools#375

 - Legacy-Id: 2509

Author: emiliosanchez

ietf/liaisons/forms.py

@@ -207,6 +207,12 @@ def save_attachments(self, instance):
             attach_file.write(attached_file.read())
             attach_file.close()
 
+    def clean_title(self):
+        title = self.cleaned_data.get('title', None)
+        exists = bool(LiaisonDetail.objects.filter(title__iexact=title).count())
+        if exists:
+            raise forms.ValidationError('A liaison statement with the same title has previously been submitted.')
+
 
 class IncomingLiaisonForm(LiaisonForm):