From 727133109cfb37d73da38d760198eb300125ddb0 Mon Sep 17 00:00:00 2001
From: Gary Wilson Jr <gary.wilson@gmail.com>
Date: Fri, 15 Aug 2008 20:09:47 +0000
Subject: [PATCH] Fixed #8290 -- Fixed DecimalField's cleaning of values with a
 large number of decimal places, based on patch from dgouldin.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8391 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/forms/fields.py                | 20 +++++++++++++++-----
 tests/regressiontests/forms/fields.py | 27 +++++++++++++++++++++++++++
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/django/forms/fields.py b/django/forms/fields.py
index f3e5528f23..06feb65f30 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -244,18 +244,28 @@ class DecimalField(Field):
             value = Decimal(value)
         except DecimalException:
             raise ValidationError(self.error_messages['invalid'])
-        pieces = str(value).lstrip("-").split('.')
-        decimals = (len(pieces) == 2) and len(pieces[1]) or 0
-        digits = len(pieces[0])
+
+        sign, digittuple, exponent = value.as_tuple()
+        decimals = abs(exponent)
+        # digittuple doesn't include any leading zeros.
+        digits = len(digittuple)
+        if decimals >= digits:
+            # We have leading zeros up to or past the decimal point.  Count
+            # everything past the decimal point as a digit.  We also add one
+            # for leading zeros before the decimal point (any number of leading
+            # whole zeros collapse to one digit).
+            digits = decimals + 1
+        whole_digits = digits - decimals
+
         if self.max_value is not None and value > self.max_value:
             raise ValidationError(self.error_messages['max_value'] % self.max_value)
         if self.min_value is not None and value < self.min_value:
             raise ValidationError(self.error_messages['min_value'] % self.min_value)
-        if self.max_digits is not None and (digits + decimals) > self.max_digits:
+        if self.max_digits is not None and digits > self.max_digits:
             raise ValidationError(self.error_messages['max_digits'] % self.max_digits)
         if self.decimal_places is not None and decimals > self.decimal_places:
             raise ValidationError(self.error_messages['max_decimal_places'] % self.decimal_places)
-        if self.max_digits is not None and self.decimal_places is not None and digits > (self.max_digits - self.decimal_places):
+        if self.max_digits is not None and self.decimal_places is not None and whole_digits > (self.max_digits - self.decimal_places):
             raise ValidationError(self.error_messages['max_whole_digits'] % (self.max_digits - self.decimal_places))
         return value
 
diff --git a/tests/regressiontests/forms/fields.py b/tests/regressiontests/forms/fields.py
index a9aae4f442..ab7968f4a4 100644
--- a/tests/regressiontests/forms/fields.py
+++ b/tests/regressiontests/forms/fields.py
@@ -403,6 +403,33 @@ True
 >>> f.clean('00.50') == Decimal("0.50")
 True
 
+
+>>> f = DecimalField(decimal_places=2)
+>>> f.clean('0.00000001')
+Traceback (most recent call last):
+...
+ValidationError: [u'Ensure that there are no more than 2 decimal places.']
+
+
+>>> f = DecimalField(max_digits=3)
+
+# Leading whole zeros "collapse" to one digit.
+>>> f.clean('0000000.10') == Decimal("0.1")
+True
+>>> f.clean('0000000.100')
+Traceback (most recent call last):
+...
+ValidationError: [u'Ensure that there are no more than 3 digits in total.']
+
+# Only leading whole zeros "collapse" to one digit.
+>>> f.clean('000000.02') == Decimal('0.02')
+True
+>>> f.clean('000000.002')
+Traceback (most recent call last):
+...
+ValidationError: [u'Ensure that there are no more than 3 digits in total.']
+
+
 # DateField ###################################################################
 
 >>> import datetime