Merge branch 'master' into schema-alteration

8 files changed, 27 insertions, 30 deletions

diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index 90f5018f8b..fd9655077e 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -30,6 +30,11 @@ if (version < (1, 2, 1) or (version[:3] == (1, 2, 1) and
 from MySQLdb.converters import conversions, Thing2Literal
 from MySQLdb.constants import FIELD_TYPE, CLIENT
 
+try:
+    import pytz
+except ImportError:
+    pytz = None
+
 from django.conf import settings
 from django.db import utils
 from django.db.backends import *
@@ -123,7 +128,7 @@ class CursorWrapper(object):
         except Database.OperationalError as e:
             # Map some error codes to IntegrityError, since they seem to be
             # misclassified and Django would prefer the more logical place.
-            if e[0] in self.codes_for_integrityerror:
+            if e.args[0] in self.codes_for_integrityerror:
                 six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
             raise
 
@@ -133,7 +138,7 @@ class CursorWrapper(object):
         except Database.OperationalError as e:
             # Map some error codes to IntegrityError, since they seem to be
             # misclassified and Django would prefer the more logical place.
-            if e[0] in self.codes_for_integrityerror:
+            if e.args[0] in self.codes_for_integrityerror:
                 six.reraise(utils.IntegrityError, utils.IntegrityError(*tuple(e.args)), sys.exc_info()[2])
             raise
 
@@ -190,6 +195,15 @@ class DatabaseFeatures(BaseDatabaseFeatures):
 
     @cached_property
     def has_zoneinfo_database(self):
+        # MySQL accepts full time zones names (eg. Africa/Nairobi) but rejects
+        # abbreviations (eg. EAT). When pytz isn't installed and the current
+        # time zone is LocalTimezone (the only sensible value in this
+        # context), the current time zone name will be an abbreviation. As a
+        # consequence, MySQL cannot perform time zone conversions reliably.
+        if pytz is None:
+            return False
+
+        # Test if the time zone definitions are installed.
         cursor = self.connection.cursor()
         cursor.execute("SELECT 1 FROM mysql.time_zone LIMIT 1")
         return cursor.fetchone() is not None
@@ -395,8 +409,9 @@ class DatabaseWrapper(BaseDatabaseWrapper):
         kwargs = {
             'conv': django_conversions,
             'charset': 'utf8',
-            'use_unicode': True,
         }
+        if not six.PY3:
+            kwargs['use_unicode'] = True
         settings_dict = self.settings_dict
         if settings_dict['USER']:
             kwargs['user'] = settings_dict['USER']
diff --git a/django/db/backends/mysql/validation.py b/django/db/backends/mysql/validation.py
index de7474d1e5..2ce957cce7 100644
--- a/django/db/backends/mysql/validation.py
+++ b/django/db/backends/mysql/validation.py
@@ -10,6 +10,7 @@ class DatabaseValidation(BaseDatabaseValidation):
         from django.db import models
         varchar_fields = (models.CharField, models.CommaSeparatedIntegerField,
                 models.SlugField)
-        if isinstance(f, varchar_fields) and f.max_length > 255 and f.unique:
+        if (isinstance(f, varchar_fields) and f.unique
+                and (f.max_length is None or int(f.max_length) > 255)):
             msg = '"%(name)s": %(cls)s cannot have a "max_length" greater than 255 when using "unique=True".'
             errors.add(opts, msg % {'name': f.name, 'cls': f.__class__.__name__})
diff --git a/django/db/models/__init__.py b/django/db/models/__init__.py
index 6c5ccd4bd2..5f17229753 100644
--- a/django/db/models/__init__.py
+++ b/django/db/models/__init__.py
@@ -1,3 +1,5 @@
+from functools import wraps
+
 from django.core.exceptions import ObjectDoesNotExist, ImproperlyConfigured
 from django.db.models.loading import get_apps, get_app, get_models, get_model, register_models
 from django.db.models.query import Q
@@ -11,7 +13,6 @@ from django.db.models.fields.files import FileField, ImageField
 from django.db.models.fields.related import ForeignKey, ForeignObject, OneToOneField, ManyToManyField, ManyToOneRel, ManyToManyRel, OneToOneRel
 from django.db.models.deletion import CASCADE, PROTECT, SET, SET_NULL, SET_DEFAULT, DO_NOTHING, ProtectedError
 from django.db.models import signals
-from django.utils.decorators import wraps
 
 
 def permalink(func):
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index c30ba03489..37fa8b1027 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -204,9 +204,6 @@ class SingleRelatedObjectDescriptor(six.with_metaclass(RenameRelatedObjectDescri
             return rel_obj
 
     def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError("%s must be accessed via instance" % self.related.opts.object_name)
-
         # The similarity of the code below to the code in
         # ReverseSingleRelatedObjectDescriptor is annoying, but there's a bunch
         # of small differences that would make a common base class convoluted.
@@ -310,9 +307,6 @@ class ReverseSingleRelatedObjectDescriptor(six.with_metaclass(RenameRelatedObjec
             return rel_obj
 
     def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError("%s must be accessed via instance" % self.field.name)
-
         # If null=True, we can assign null here, but otherwise the value needs
         # to be an instance of the related class.
         if value is None and self.field.null == False:
@@ -382,9 +376,6 @@ class ForeignRelatedObjectsDescriptor(object):
         return self.related_manager_cls(instance)
 
     def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError("Manager must be accessed via instance")
-
         manager = self.__get__(instance)
         # If the foreign key can support nulls, then completely clear the related set.
         # Otherwise, just move the named objects into the set.
@@ -765,9 +756,6 @@ class ManyRelatedObjectsDescriptor(object):
         return manager
 
     def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError("Manager must be accessed via instance")
-
         if not self.related.field.rel.through._meta.auto_created:
             opts = self.related.field.rel.through._meta
             raise AttributeError("Cannot set values on a ManyToManyField which specifies an intermediary model. Use %s.%s's Manager instead." % (opts.app_label, opts.object_name))
@@ -822,9 +810,6 @@ class ReverseManyRelatedObjectsDescriptor(object):
         return manager
 
     def __set__(self, instance, value):
-        if instance is None:
-            raise AttributeError("Manager must be accessed via instance")
-
         if not self.field.rel.through._meta.auto_created:
             opts = self.field.rel.through._meta
             raise AttributeError("Cannot set values on a ManyToManyField which specifies an intermediary model.  Use %s.%s's Manager instead." % (opts.app_label, opts.object_name))
diff --git a/django/db/models/query.py b/django/db/models/query.py
index c36d81cc31..337049e2ff 100644
--- a/django/db/models/query.py
+++ b/django/db/models/query.py
@@ -312,11 +312,7 @@ class QuerySet(object):
                 if skip:
                     obj = model_cls(**dict(zip(init_list, row_data)))
                 else:
-                    try:
-                        obj = model(*row_data)
-                    except IndexError:
-                        import ipdb; ipdb.set_trace()
-                        pass
+                    obj = model(*row_data)
 
                 # Store the source database of the object
                 obj._state.db = db
diff --git a/django/db/models/query_utils.py b/django/db/models/query_utils.py
index a33c44833c..ee7a56a26c 100644
--- a/django/db/models/query_utils.py
+++ b/django/db/models/query_utils.py
@@ -102,7 +102,7 @@ class DeferredAttribute(object):
                 f = [f for f in opts.fields
                      if f.attname == self.field_name][0]
             name = f.name
-            # Lets see if the field is part of the parent chain. If so we
+            # Let's see if the field is part of the parent chain. If so we
             # might be able to reuse the already loaded value. Refs #18343.
             val = self._check_parent_chain(instance, name)
             if val is None:
@@ -194,8 +194,7 @@ def deferred_class_factory(model, attrs):
     name = "%s_Deferred_%s" % (model.__name__, '_'.join(sorted(list(attrs))))
     name = util.truncate_name(name, 80, 32)
 
-    overrides = dict([(attr, DeferredAttribute(attr, model))
-            for attr in attrs])
+    overrides = dict((attr, DeferredAttribute(attr, model)) for attr in attrs)
     overrides["Meta"] = Meta
     overrides["__module__"] = model.__module__
     overrides["_deferred"] = True
diff --git a/django/db/models/sql/compiler.py b/django/db/models/sql/compiler.py
index 3444b74ac3..018fc098ea 100644
--- a/django/db/models/sql/compiler.py
+++ b/django/db/models/sql/compiler.py
@@ -1092,7 +1092,7 @@ class SQLDateTimeCompiler(SQLCompiler):
                     if datetime is None:
                         raise ValueError("Database returned an invalid value "
                                          "in QuerySet.dates(). Are time zone "
-                                         "definitions installed?")
+                                         "definitions and pytz installed?")
                     datetime = datetime.replace(tzinfo=None)
                     datetime = timezone.make_aware(datetime, self.query.tzinfo)
                 yield datetime
diff --git a/django/db/utils.py b/django/db/utils.py
index 936b42039d..e84060f9b3 100644
--- a/django/db/utils.py
+++ b/django/db/utils.py
@@ -169,7 +169,7 @@ class ConnectionHandler(object):
         conn.setdefault('ENGINE', 'django.db.backends.dummy')
         if conn['ENGINE'] == 'django.db.backends.' or not conn['ENGINE']:
             conn['ENGINE'] = 'django.db.backends.dummy'
-        conn.setdefault('CONN_MAX_AGE', 600)
+        conn.setdefault('CONN_MAX_AGE', 0)
         conn.setdefault('OPTIONS', {})
         conn.setdefault('TIME_ZONE', 'UTC' if settings.USE_TZ else settings.TIME_ZONE)
         for setting in ['NAME', 'USER', 'PASSWORD', 'HOST', 'PORT']: