accommodate custom user models in migration

wagtail/wagtailimages/south_migrations/0005_make_filter_spec_unique.py

@@ -4,6 +4,8 @@ from south.db import db
 from south.v2 import SchemaMigration
 from django.db import models
 
+from wagtail.wagtailcore.compat import AUTH_USER_MODEL, AUTH_USER_MODEL_NAME
+
 
 class Migration(SchemaMigration):
 
@@ -31,8 +33,8 @@ class Migration(SchemaMigration):
             'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'name': ('django.db.models.fields.CharField', [], {'max_length': '50'})
         },
-        'auth.user': {
-            'Meta': {'object_name': 'User'},
+        AUTH_USER_MODEL: {
+            'Meta': {'object_name': AUTH_USER_MODEL_NAME},
             'date_joined': ('django.db.models.fields.DateTimeField', [], {'default': 'datetime.datetime.now'}),
             'email': ('django.db.models.fields.EmailField', [], {'max_length': '75', 'blank': 'True'}),
             'first_name': ('django.db.models.fields.CharField', [], {'max_length': '30', 'blank': 'True'}),
@@ -70,7 +72,7 @@ class Migration(SchemaMigration):
             'height': ('django.db.models.fields.IntegerField', [], {}),
             'id': ('django.db.models.fields.AutoField', [], {'primary_key': 'True'}),
             'title': ('django.db.models.fields.CharField', [], {'max_length': '255'}),
-            'uploaded_by_user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['auth.User']", 'null': 'True', 'blank': 'True'}),
+            'uploaded_by_user': ('django.db.models.fields.related.ForeignKey', [], {'to': "orm['%s']" % AUTH_USER_MODEL, 'null': 'True', 'blank': 'True'}),
             'width': ('django.db.models.fields.IntegerField', [], {})
         },
         'wagtailimages.rendition': {