fix

article/forms.py

@@ -57,7 +57,9 @@ class BlogForm(forms.Form):
             article.author = author
 
         article.type = self.type
-        article.slug = data.get('slug')
+        if not getattr(article, 'slug', None):
+            article.slug = data['slug']                    
+
         if data['logo']:
             article.logo = data['logo']
         article.publish_date = data['publish_date']