Ticket #12404: 12404_patch.diff

django/core/management/validation.py

@@ -37 +37 @@
                 e.add(opts, '"%s": You can\'t use "id" as a field name, because each model automatically gets an "id" field if none of the fields have primary_key=True. You need to either remove/rename your "id" field or add primary_key=True to a field.' % f.name)
             if f.name.endswith('_'):
                 e.add(opts, '"%s": Field names cannot end with underscores, because this would lead to ambiguous queryset filters.' % f.name)
-            if isinstance(f, models.CharField) and f.max_length in (None, 0):
-                e.add(opts, '"%s": CharFields require a "max_length" attribute.' % f.name)
+            if isinstance(f, models.CharField):
+                try:
+                    max_length = int(f.max_length)
+                    if max_length <= 0:
+                        e.add(opts, '"%s": CharFields require a "max_length attribute greater than zero."' % f.name)
+                except ValueError:
+                    e.add(opts, '"%s": CharFields require a "max_length" attribute of type int.' % f.name)
             if isinstance(f, models.DecimalField):
                 if f.decimal_places is None:
                     e.add(opts, '"%s": DecimalFields require a "decimal_places" attribute.' % f.name)