Ticket #5079: 5079_4.diff

django/db/models/fields/__init__.py

@@ -686 +686 @@
         if value < 0:
             num_chars += 1
 
-        return u"%.*f" % (self.decimal_places, value)
+        if isinstance(value, decimal.Decimal):
+            if not hasattr(self, '_context'):
+                self._context = decimal.getcontext().copy()
+                self._context.prec = self.decimal_places
 
+            return value.quantize(decimal.Decimal('.1')**self.decimal_places, context = self._context)
+        else:
+            return u"%.*f" % (self.decimal_places, value)
+
     def get_db_prep_save(self, value):
         if value is not None:
             value = self._format(value)

tests/regressiontests/model_fields/tests.py

@@ -1 @@
-"""
+
+
+from django.db import models
+from decimal import Decimal
+
+class DecimalTest(models.Model):
+    field = models.DecimalField(max_digits=35, decimal_places=30)
+
+__test__ = {'API_TESTS': """
 >>> from django.db.models.fields import *
 
 # DecimalField
@@ -15 +23 @@
 Traceback (most recent call last):
 ...
 ValidationError: [u'This value must be a decimal number.']
-"""
+
+# added after #5079 
+>>> b1 = DecimalTest(field=Decimal(".1"))
+>>> b1.field
+Decimal("0.1")
+>>> b1.save()
+>>> b1.field
+Decimal("0.1")
+
+>>> b2 = DecimalTest.objects.get(id=1)
+>>> b2.field.normalize()
+Decimal("0.1")
+
+# this should fit in 
+>>> b1 = DecimalTest(field=Decimal(".100000000000000000000000000005"))
+>>> b1.field
+Decimal("0.100000000000000000000000000005")
+>>> b1.save()
+>>> b1.field
+Decimal("0.100000000000000000000000000005")
+>>> b2 = DecimalTest.objects.get(id=b1.id)
+>>> b2.field
+Decimal("0.100000000000000000000000000005")
+
+# this shouldn't!
+>>> b1 = DecimalTest(field=Decimal(".100000000000000000000000000000000000000000000005"))
+>>> b1.field
+Decimal("0.100000000000000000000000000000000000000000000005")
+>>> b1.save()
+>>> b2 = DecimalTest.objects.get(id=b1.id)
+>>> b2.field.normalize()
+Decimal("0.1")
+
+"""}