[1.7.x] Fixed #22576: Ensure makemigrations doesn't touch the database.

django/core/management/commands/makemigrations.py

@@ -50,10 +50,9 @@ class Command(BaseCommand):
                 self.stderr.write("App '%s' could not be found. Is it in INSTALLED_APPS?" % app_label)
             sys.exit(2)
 
-        # Load the current graph state. Takes a connection, but it's not used
-        # (makemigrations doesn't look at the database state).
-        # Also make sure the graph is built without unmigrated apps shoehorned in.
-        loader = MigrationLoader(connections[DEFAULT_DB_ALIAS])
+        # Load the current graph state. Pass in None for the connection so
+        # the loader doesn't try to resolve replaced migrations from DB.
+        loader = MigrationLoader(None)
 
         # Before anything else, see if there's conflicting apps and drop out
         # hard if there are any and they don't want to merge

django/db/migrations/loader.py

@@ -143,6 +143,9 @@ class MigrationLoader(object):
         # Load disk data
         self.load_disk()
         # Load database data
+        if self.connection is None:
+            self.applied_migrations = set()
+        else:
             recorder = MigrationRecorder(self.connection)
             self.applied_migrations = recorder.applied_migrations()
         # Do a first pass to separate out replacing and non-replacing migrations