Admin read-only fields should be included in POST
|Reported by:||jonash||Owned by:||nobody|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
Fields marked readonly in the admin are not included in the POST in case the model is saved. Now if such field does not have @blank=True@, the form doesn't validate since a non-blank field is missing a value.
These values should be included in the form as hidden fields.