JSONField has_changed doesn't reflect disabled correctly

[alex]

Problem:

A disabled JSONField still reports changes via has_changed.

Why?

def has_changed(self, initial, data):
    # here we miss the check for disabled
    if super().has_changed(initial, data):
        return True
    ...

As we see, has_changed from the base is called and if successful, True is returned. But we have no additional check for disabled.

Fix:

def has_changed(self, initial, data):
    if self.disabled:
        return False
    if super().has_changed(initial, data):
        return True
    ...

This corrupts the changed fields in the history of admin (disabled JSONFields are always shown as changed).