Fixed #22172 -- Allowed index_together to be a single list (rather than list of lists)..

Thanks EmilStenstrom for the suggestion.

django/db/migrations/operations/models.py

@@ -1,5 +1,5 @@
 from django.db import models, router
-from django.db.models.options import normalize_unique_together
+from django.db.models.options import normalize_together
 from django.db.migrations.state import ModelState
 from django.db.migrations.operations.base import Operation
 from django.utils import six
@@ -183,7 +183,7 @@ class AlterUniqueTogether(Operation):
 
     def __init__(self, name, unique_together):
         self.name = name
-        unique_together = normalize_unique_together(unique_together)
+        unique_together = normalize_together(unique_together)
         self.unique_together = set(tuple(cons) for cons in unique_together)
 
     def state_forwards(self, app_label, state):
@@ -220,6 +220,7 @@ class AlterIndexTogether(Operation):
 
     def __init__(self, name, index_together):
         self.name = name
+        index_together = normalize_together(index_together)
         self.index_together = set(tuple(cons) for cons in index_together)
 
     def state_forwards(self, app_label, state):

django/db/migrations/state.py

@@ -1,7 +1,7 @@
 from django.apps import AppConfig
 from django.apps.registry import Apps
 from django.db import models
-from django.db.models.options import DEFAULT_NAMES, normalize_unique_together
+from django.db.models.options import DEFAULT_NAMES, normalize_together
 from django.utils import six
 from django.utils.module_loading import import_string
 
@@ -145,7 +145,10 @@ class ModelState(object):
             elif name in model._meta.original_attrs:
                 if name == "unique_together":
                     ut = model._meta.original_attrs["unique_together"]
-                    options[name] = set(normalize_unique_together(ut))
+                    options[name] = set(normalize_together(ut))
+                elif name == "index_together":
+                    it = model._meta.original_attrs["index_together"]
+                    options[name] = set(normalize_together(it))
                 else:
                     options[name] = model._meta.original_attrs[name]
         # Make our record

django/db/models/options.py

@@ -24,24 +24,26 @@ DEFAULT_NAMES = ('verbose_name', 'verbose_name_plural', 'db_table', 'ordering',
                  'select_on_save')
 
 
-def normalize_unique_together(unique_together):
+def normalize_together(option_together):
     """
-    unique_together can be either a tuple of tuples, or a single
+    option_together can be either a tuple of tuples, or a single
     tuple of two strings. Normalize it to a tuple of tuples, so that
     calling code can uniformly expect that.
     """
     try:
-        if not unique_together:
+        if not option_together:
             return ()
-        first_element = next(iter(unique_together))
+        if not isinstance(option_together, (tuple, list)):
+            raise TypeError
+        first_element = next(iter(option_together))
         if not isinstance(first_element, (tuple, list)):
-            unique_together = (unique_together,)
+            option_together = (option_together,)
         # Normalize everything to tuples
-        return tuple(tuple(ut) for ut in unique_together)
+        return tuple(tuple(ot) for ot in option_together)
     except TypeError:
-        # If the value of unique_together isn't valid, return it
+        # If the value of option_together isn't valid, return it
         # verbatim; this will be picked up by the check framework later.
-        return unique_together
+        return option_together
 
 
 @python_2_unicode_compatible
@@ -140,7 +142,10 @@ class Options(object):
                     self.original_attrs[attr_name] = getattr(self, attr_name)
 
             ut = meta_attrs.pop('unique_together', self.unique_together)
-            self.unique_together = normalize_unique_together(ut)
+            self.unique_together = normalize_together(ut)
+
+            it = meta_attrs.pop('index_together', self.index_together)
+            self.index_together = normalize_together(it)
 
             # verbose_name_plural is a special case because it uses a 's'
             # by default.