From 07ba148d9e4c98d0e5a0415a6e805af6431da277 Mon Sep 17 00:00:00 2001
From: Alex Hill <alex@hill.net.au>
Date: Thu, 2 Apr 2015 00:57:53 +0800
Subject: [PATCH] Cleaned up use of context manager in SQLite schema editor

---
 django/db/backends/sqlite3/schema.py | 32 +++++++++++++---------------
 1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/django/db/backends/sqlite3/schema.py b/django/db/backends/sqlite3/schema.py
index 0664d31e7a0..5ce7a964e67 100644
--- a/django/db/backends/sqlite3/schema.py
+++ b/django/db/backends/sqlite3/schema.py
@@ -168,27 +168,25 @@ class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
             yield
             model._meta.db_table = original_table_name
 
-        # Rename the old table to something temporary
-        old_table_name = model._meta.db_table + "__old"
-        with altered_table_name(model, old_table_name):
+        with altered_table_name(model, model._meta.db_table + "__old"):
+            # Rename the old table to make way for the new
             self.alter_db_table(model, temp_model._meta.db_table, model._meta.db_table)
 
-        # Create a new table with that format. We remove things from the
-        # deferred SQL that match our table name, too
-        self.deferred_sql = [x for x in self.deferred_sql if temp_model._meta.db_table not in x]
-        self.create_model(temp_model)
+            # Create a new table with the updated schema. We remove things
+            # from the deferred SQL that match our table name, too
+            self.deferred_sql = [x for x in self.deferred_sql if temp_model._meta.db_table not in x]
+            self.create_model(temp_model)
 
-        # Copy data from the old table
-        field_maps = list(mapping.items())
-        self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
-            self.quote_name(temp_model._meta.db_table),
-            ', '.join(self.quote_name(x) for x, y in field_maps),
-            ', '.join(y for x, y in field_maps),
-            self.quote_name(old_table_name),
-        ))
+            # Copy data from the old table into the new table
+            field_maps = list(mapping.items())
+            self.execute("INSERT INTO %s (%s) SELECT %s FROM %s" % (
+                self.quote_name(temp_model._meta.db_table),
+                ', '.join(self.quote_name(x) for x, y in field_maps),
+                ', '.join(y for x, y in field_maps),
+                self.quote_name(model._meta.db_table),
+            ))
 
-        # Delete the old table
-        with altered_table_name(model, old_table_name):
+            # Delete the old table
             self.delete_model(model, handle_autom2m=False)
 
         # Run deferred SQL on correct table