Fixed #9218 -- Simplified the fix from #9039 and added tests to ensure this case doesn't break again (and that the simplification didn't break anything).

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9341 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/forms/models.py

@@ -234,7 +234,7 @@ class BaseModelForm(BaseForm):
         # equal NULL in SQL we should not do any unique checking for NULL values.
         unique_checks = []
         for check in self.instance._meta.unique_together[:]:
-            fields_on_form = [field for field in check if field in self.cleaned_data and not self.cleaned_data[field] is None]
+            fields_on_form = [field for field in check if self.cleaned_data.get(field) is not None]
             if len(fields_on_form) == len(check):
                 unique_checks.append(check)
 
@@ -248,7 +248,7 @@ class BaseModelForm(BaseForm):
             except FieldDoesNotExist:
                 # This is an extra field that's not on the ModelForm, ignore it
                 continue
-            if f.unique and name in self.cleaned_data and not self.cleaned_data[name] is None:
+            if f.unique and self.cleaned_data.get(name) is not None:
                 unique_checks.append((name,))
 
         bad_fields = set()

tests/modeltests/model_forms/models.py

@@ -159,6 +159,15 @@ class Book(models.Model):
     class Meta:
         unique_together = ('title', 'author')
         
+class ExplicitPK(models.Model):
+    key = models.CharField(max_length=20, primary_key=True)
+    desc = models.CharField(max_length=20, blank=True, unique=True)
+    class Meta:
+        unique_together = ('key', 'desc')
+    
+    def __unicode__(self):
+        return self.key
+
 __test__ = {'API_TESTS': """
 >>> from django import forms
 >>> from django.forms.models import ModelForm, model_to_dict
@@ -1247,6 +1256,27 @@ True
 >>> form.is_valid()
 True
 
+# Test for primary_key being in the form and failing validation.
+>>> class ExplicitPKForm(ModelForm):
+...     class Meta:
+...         model = ExplicitPK
+...         fields = ('key', 'desc',)
+>>> form = ExplicitPKForm({'key': u'', 'desc': u'' })
+>>> form.is_valid()
+False
+
+# Ensure keys and blank character strings are tested for uniqueness.
+>>> form = ExplicitPKForm({'key': u'key1', 'desc': u''})
+>>> form.is_valid()
+True
+>>> form.save()
+<ExplicitPK: key1>
+>>> form = ExplicitPKForm({'key': u'key1', 'desc': u''})
+>>> form.is_valid()
+False
+>>> form.errors
+{'__all__': [u'Explicit pk with this Key and Desc already exists.'], 'key': [u'Explicit pk with this Key already exists.'], 'desc': [u'Explicit pk with this Desc already exists.']}
+
 # Choices on CharField and IntegerField
 >>> class ArticleForm(ModelForm):
 ...     class Meta: