From a43c2f50c2106d868045c7858de219de9717836c Mon Sep 17 00:00:00 2001
From: Ramiro Morales <cramm0@gmail.com>
Date: Wed, 29 Dec 2010 01:18:11 +0000
Subject: [PATCH] Fixed #7726 -- Added validation of max_digits and
 decimal_places options to DecimalField model field. Thanks theevilgeek for
 the report and elbarto for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15094 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/core/management/validation.py      | 9 +++++++++
 docs/ref/models/fields.txt                | 5 +++--
 tests/modeltests/invalid_models/models.py | 4 ++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/django/core/management/validation.py b/django/core/management/validation.py
index f78fa87b33..2eb6340de9 100644
--- a/django/core/management/validation.py
+++ b/django/core/management/validation.py
@@ -53,11 +53,14 @@ def get_validation_errors(outfile, app=None):
                 except (ValueError, TypeError):
                     e.add(opts, '"%s": CharFields require a "max_length" attribute that is a positive integer.' % f.name)
             if isinstance(f, models.DecimalField):
+                decimalp_ok, mdigits_ok = False, False
                 decimalp_msg ='"%s": DecimalFields require a "decimal_places" attribute that is a non-negative integer.'
                 try:
                     decimal_places = int(f.decimal_places)
                     if decimal_places < 0:
                         e.add(opts, decimalp_msg % f.name)
+                    else:
+                        decimalp_ok = True
                 except (ValueError, TypeError):
                     e.add(opts, decimalp_msg % f.name)
                 mdigits_msg = '"%s": DecimalFields require a "max_digits" attribute that is a positive integer.'
@@ -65,8 +68,14 @@ def get_validation_errors(outfile, app=None):
                     max_digits = int(f.max_digits)
                     if max_digits <= 0:
                         e.add(opts,  mdigits_msg % f.name)
+                    else:
+                        mdigits_ok = True
                 except (ValueError, TypeError):
                     e.add(opts, mdigits_msg % f.name)
+                invalid_values_msg = '"%s": DecimalFields require a "max_digits" attribute value that is greater than the value of the "decimal_places" attribute.'
+                if decimalp_ok and mdigits_ok:
+                    if decimal_places >= max_digits:
+                        e.add(opts, invalid_values_msg % f.name)
             if isinstance(f, models.FileField) and not f.upload_to:
                 e.add(opts, '"%s": FileFields require an "upload_to" attribute.' % f.name)
             if isinstance(f, models.ImageField):
diff --git a/docs/ref/models/fields.txt b/docs/ref/models/fields.txt
index 0399eccf67..583dfb499c 100644
--- a/docs/ref/models/fields.txt
+++ b/docs/ref/models/fields.txt
@@ -437,11 +437,12 @@ A fixed-precision decimal number, represented in Python by a
 
 .. attribute:: DecimalField.max_digits
 
-    The maximum number of digits allowed in the number
+    The maximum number of digits allowed in the number. Note that this number
+    must be greater than ``decimal_places``, if it exists.
 
 .. attribute:: DecimalField.decimal_places
 
-    The number of decimal places to store with the number
+    The number of decimal places to store with the number.
 
 For example, to store numbers up to 999 with a resolution of 2 decimal places,
 you'd use::
diff --git a/tests/modeltests/invalid_models/models.py b/tests/modeltests/invalid_models/models.py
index 2788aa077e..ab9edd6461 100644
--- a/tests/modeltests/invalid_models/models.py
+++ b/tests/modeltests/invalid_models/models.py
@@ -14,6 +14,8 @@ class FieldErrors(models.Model):
     decimalfield = models.DecimalField()
     decimalfield2 = models.DecimalField(max_digits=-1, decimal_places=-1)
     decimalfield3 = models.DecimalField(max_digits="bad", decimal_places="bad")
+    decimalfield4 = models.DecimalField(max_digits=9, decimal_places=10)
+    decimalfield5 = models.DecimalField(max_digits=10, decimal_places=10)
     filefield = models.FileField()
     choices = models.CharField(max_length=10, choices='bad')
     choices2 = models.CharField(max_length=10, choices=[(1,2,3),(1,2,3)])
@@ -241,6 +243,8 @@ invalid_models.fielderrors: "decimalfield2": DecimalFields require a "decimal_pl
 invalid_models.fielderrors: "decimalfield2": DecimalFields require a "max_digits" attribute that is a positive integer.
 invalid_models.fielderrors: "decimalfield3": DecimalFields require a "decimal_places" attribute that is a non-negative integer.
 invalid_models.fielderrors: "decimalfield3": DecimalFields require a "max_digits" attribute that is a positive integer.
+invalid_models.fielderrors: "decimalfield4": DecimalFields require a "max_digits" attribute value that is greater than the value of the "decimal_places" attribute.
+invalid_models.fielderrors: "decimalfield5": DecimalFields require a "max_digits" attribute value that is greater than the value of the "decimal_places" attribute.
 invalid_models.fielderrors: "filefield": FileFields require an "upload_to" attribute.
 invalid_models.fielderrors: "choices": "choices" should be iterable (e.g., a tuple or list).
 invalid_models.fielderrors: "choices2": "choices" should be a sequence of two-tuples.