[1.5.x] Fixed #20025 -- Pointed to a MySQLdb fork for Python 3.

Made a few minor compatibility adjustments.

Backport of e81e319f from master.

2 files changed, 4 insertions, 2 deletions

diff --git a/django/db/backends/mysql/base.py b/django/db/backends/mysql/base.py
index 65db3b6acb..38cf7e4284 100644
--- a/django/db/backends/mysql/base.py
+++ b/django/db/backends/mysql/base.py
@@ -383,8 +383,9 @@ 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__})