[1.7.x] Fixed #12030 -- Validate integer field range at the model level.

Thanks to @timgraham for the review.

Backport of 1506c71a95 from master

5 files changed, 47 insertions, 0 deletions

diff --git a/django/db/backends/__init__.py b/django/db/backends/__init__.py
index b274065a21..98dab13ba8 100644
--- a/django/db/backends/__init__.py
+++ b/django/db/backends/__init__.py
@@ -722,6 +722,16 @@ class BaseDatabaseOperations(object):
     """
     compiler_module = "django.db.models.sql.compiler"
 
+    # Integer field safe ranges by `internal_type` as documented
+    # in docs/ref/models/fields.txt.
+    integer_field_ranges = {
+        'SmallIntegerField': (-32768, 32767),
+        'IntegerField': (-2147483648, 2147483647),
+        'BigIntegerField': (-9223372036854775808, 9223372036854775807),
+        'PositiveSmallIntegerField': (0, 32767),
+        'PositiveIntegerField': (0, 2147483647),
+    }
+
     def __init__(self, connection):
         self.connection = connection
         self._cache = None
@@ -1206,6 +1216,14 @@ class BaseDatabaseOperations(object):
         """
         return params
 
+    def integer_field_range(self, internal_type):
+        """
+        Given an integer field internal type (e.g. 'PositiveIntegerField'),
+        returns a tuple of the (min_value, max_value) form representing the
+        range of the column type bound to the field.
+        """
+        return self.integer_field_ranges[internal_type]
+
 
 # Structure returned by the DB-API cursor.description interface (PEP 249)
 FieldInfo = namedtuple('FieldInfo',
diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index e79f980e21..61a8ab72fc 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -223,6 +223,12 @@ class DatabaseFeatures(BaseDatabaseFeatures):
 class DatabaseOperations(BaseDatabaseOperations):
     compiler_module = "django.db.backends.mysql.compiler"
 
+    # MySQL stores positive fields as UNSIGNED ints.
+    integer_field_ranges = dict(BaseDatabaseOperations.integer_field_ranges,
+        PositiveSmallIntegerField=(0, 4294967295),
+        PositiveIntegerField=(0, 18446744073709551615),
+    )
+
     def date_extract_sql(self, lookup_type, field_name):
         # http://dev.mysql.com/doc/mysql/en/date-and-time-functions.html
         if lookup_type == 'week_day':
diff --git a/django/db/backends/oracle/base.py b/django/db/backends/oracle/base.py
index 0c799055fb..830a8a9862 100644
--- a/django/db/backends/oracle/base.py
+++ b/django/db/backends/oracle/base.py
@@ -121,6 +121,15 @@ class DatabaseFeatures(BaseDatabaseFeatures):
 class DatabaseOperations(BaseDatabaseOperations):
     compiler_module = "django.db.backends.oracle.compiler"
 
+    # Oracle uses NUMBER(11) and NUMBER(19) for integer fields.
+    integer_field_ranges = {
+        'SmallIntegerField': (-99999999999, 99999999999),
+        'IntegerField': (-99999999999, 99999999999),
+        'BigIntegerField': (-9999999999999999999, 9999999999999999999),
+        'PositiveSmallIntegerField': (0, 99999999999),
+        'PositiveIntegerField': (0, 99999999999),
+    }
+
     def autoinc_sql(self, table, column):
         # To simulate auto-incrementing primary keys in Oracle, we have to
         # create a sequence and a trigger.
diff --git a/django/db/backends/sqlite3/base.py b/django/db/backends/sqlite3/base.py
index 3bb85e042d..9709e8449f 100644
--- a/django/db/backends/sqlite3/base.py
+++ b/django/db/backends/sqlite3/base.py
@@ -292,6 +292,10 @@ class DatabaseOperations(BaseDatabaseOperations):
             return 'django_power(%s)' % ','.join(sub_expressions)
         return super(DatabaseOperations, self).combine_expression(connector, sub_expressions)
 
+    def integer_field_range(self, internal_type):
+        # SQLite doesn't enforce any integer constraints
+        return (None, None)
+
 
 class DatabaseWrapper(BaseDatabaseWrapper):
     vendor = 'sqlite'
diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index 8dfe7e79e5..4ebb6049b3 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -1561,6 +1561,16 @@ class IntegerField(Field):
     }
     description = _("Integer")
 
+    def __init__(self, *args, **kwargs):
+        field_validators = kwargs.setdefault('validators', [])
+        internal_type = self.get_internal_type()
+        min_value, max_value = connection.ops.integer_field_range(internal_type)
+        if min_value is not None:
+            field_validators.append(validators.MinValueValidator(min_value))
+        if max_value is not None:
+            field_validators.append(validators.MaxValueValidator(max_value))
+        super(IntegerField, self).__init__(*args, **kwargs)
+
     def get_prep_value(self, value):
         value = super(IntegerField, self).get_prep_value(value)
         if value is None: