Fix Mezzanine 4.2.2 on Django 1.10+ with modeltranslation

mezzanine.patch

--- ./pages/models.py.orig      2016-09-08 03:02:33.000000000 +0200
+++ ./pages/models.py   2017-01-26 23:26:16.672548649 +0100
@@ -18,6 +18,7 @@
 from mezzanine.pages.fields import MenusField
 from mezzanine.pages.managers import PageManager
 from mezzanine.utils.urls import path_to_slug
+from mezzanine.core.models import wrapped_manager


 class BasePage(Orderable, Displayable):
@@ -27,7 +28,7 @@
     ``Page`` subclass loses the custom manager.
     """

-    objects = PageManager()
+    objects = wrapped_manager(PageManager)

     class Meta:
         abstract = True
--- ./core/models.py.orig       2016-09-26 01:49:47.000000000 +0200
+++ ./core/models.py    2017-01-26 23:31:14.478528878 +0100
@@ -32,6 +32,15 @@

 user_model_name = get_user_model_name()

+def wrapped_manager(klass):
+    if settings.USE_MODELTRANSLATION:
+        from modeltranslation.manager import MultilingualManager
+        class Mgr(MultilingualManager, klass):
+            pass
+        return Mgr()
+    else:
+        return klass()
+

 class SiteRelated(models.Model):
     """
@@ -41,7 +50,7 @@
     details.
     """

-    objects = CurrentSiteManager()
+    objects = wrapped_manager(CurrentSiteManager)

     class Meta:
         abstract = True
@@ -236,7 +245,7 @@
     short_url = models.URLField(blank=True, null=True)
     in_sitemap = models.BooleanField(_("Show in sitemap"), default=True)

-    objects = DisplayableManager()
+    objects = wrapped_manager(DisplayableManager)
     search_fields = {"keywords": 10, "title": 5}

     class Meta:
--- ./forms/models.py.orig      2016-09-19 02:20:40.000000000 +0200
+++ ./forms/models.py   2017-01-26 23:28:42.906541456 +0100
@@ -6,7 +6,7 @@

 from mezzanine.conf import settings
 from mezzanine.core.fields import RichTextField
-from mezzanine.core.models import Orderable, RichText
+from mezzanine.core.models import Orderable, RichText, wrapped_manager
 from mezzanine.forms import fields
 from mezzanine.pages.models import Page

@@ -67,7 +67,7 @@
         max_length=100)
     help_text = models.CharField(_("Help text"), blank=True, max_length=100)

-    objects = FieldManager()
+    objects = wrapped_manager(FieldManager)

     class Meta:
         abstract = True

Hi, can you explain why this commit? Since MT says in documentation:

Every model registered for translation is patched so that all its managers become subclasses of MultilingualManager (of course, if a custom manager was defined on the model, its functions will be retained). MultilingualManager simplifies language-aware queries, especially on third-party apps, by rewriting query field names.

See deschler/django-modeltranslation#389