.

atlas/forms.py

@@ -74,6 +74,29 @@ class SeriesForm(ModelForm):
             widget=FilteredSelectMultiple(verbose_name="Case", is_stacked=False),
         )
 
+    def save(self, commit=True):
+        # Get the unsaved Long instance
+        instance = ModelForm.save(self, False)
+
+        # Prepare a 'save_m2m' method for the form,
+        old_save_m2m = self.save_m2m
+
+        def save_m2m():
+            old_save_m2m()
+            instance.case.clear()
+            for case in self.cleaned_data["case"]:
+                # We need the id here
+                instance.case.add(case.pk)
+
+        self.save_m2m = save_m2m
+
+        # Do we need to save all changes now?
+        # if commit:
+        instance.save()
+        self.save_m2m()
+
+        return instance
+
     class Meta:
         model = Series
         exclude = ["author"]