[1.7.x] Fixed #23013 -- Fixed removing unique_together/index_together constraints in migrations.

Thanks melinath for the report.

Backport of 0154965392 from master

2 files changed, 2 insertions, 4 deletions

diff --git a/django/db/migrations/operations/models.py b/django/db/migrations/operations/models.py
index 1c2f209df3..1ded7c6db4 100644
--- a/django/db/migrations/operations/models.py
+++ b/django/db/migrations/operations/models.py
@@ -248,7 +248,7 @@ class AlterUniqueTogether(Operation):
         return name.lower() == self.name.lower()
 
     def describe(self):
-        return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.unique_together))
+        return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.unique_together or ''))
 
 
 class AlterIndexTogether(Operation):
@@ -288,7 +288,7 @@ class AlterIndexTogether(Operation):
         return name.lower() == self.name.lower()
 
     def describe(self):
-        return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.index_together))
+        return "Alter %s for %s (%s constraint(s))" % (self.option_name, self.name, len(self.index_together or ''))
 
 
 class AlterOrderWithRespectTo(Operation):
diff --git a/django/db/migrations/state.py b/django/db/migrations/state.py
index ab1c39f8ee..d24a37e5b9 100644
--- a/django/db/migrations/state.py
+++ b/django/db/migrations/state.py
@@ -272,8 +272,6 @@ class ModelState(object):
         # First, make a Meta object
         meta_contents = {'app_label': self.app_label, "apps": apps}
         meta_contents.update(self.options)
-        if "unique_together" in meta_contents:
-            meta_contents["unique_together"] = list(meta_contents["unique_together"])
         meta = type(str("Meta"), tuple(), meta_contents)
         # Then, work out our bases
         try: