Ticket #14885: trac#14885-is_valid.diff

docs/topics/forms/modelforms.txt

@@ -196 +196 @@
 ----------------------------------------
 
 The first time you call ``is_valid()`` or access the ``errors`` attribute of a
-``ModelForm`` triggers :ref:`form validation <form-and-field-validation>` as
-well as :ref:`model validation <validating-objects>`. This has the side-effect
-of cleaning the model you pass to the ``ModelForm`` constructor. For instance,
-calling ``is_valid()`` on your form will convert any date fields on your model
-to actual date objects.
-
+``ModelForm``, :ref:`form validation <form-and-field-validation>` and
+:ref:`model validation <validating-objects>` are triggered. This process
+updates the form's model instance in place. If the form validation fails, only
+some of the updates may be applied. For this reason, you'll probably want to
+avoid reusing the model instance.
 
 The ``save()`` method
 ---------------------