Fixed #13138: Ensure required=False on a model form field overrides

blank=False on the underlying model field during model form clean, 
in order to maintain backward compatibility. Thanks to saxon75 for 
the report.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@12802 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 7 insertions, 4 deletions

diff --git a/django/forms/models.py b/django/forms/models.py
index 13aea4acab..869138c922 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -292,13 +292,16 @@ class BaseModelForm(BaseForm):
             elif field in self._errors.keys():
                 exclude.append(f.name)
 
-            # Exclude empty fields that are not required by the form. The
-            # underlying model field may be required, so this keeps the model
-            # field from raising that error.
+            # Exclude empty fields that are not required by the form, if the
+            # underlying model field is required. This keeps the model field
+            # from raising a required error. Note: don't exclude the field from
+            # validaton if the model field allows blanks. If it does, the blank
+            # value may be included in a unique check, so cannot be excluded
+            # from validation.
             else:
                 form_field = self.fields[field]
                 field_value = self.cleaned_data.get(field, None)
-                if field_value is None and not form_field.required:
+                if not f.blank and not form_field.required and field_value in EMPTY_VALUES:
                     exclude.append(f.name)
         return exclude