Fixed #27300 -- Made makemigrations --dry-run output a string (no bytes)

Thanks Markus Holtermann for the report and the review.

3 files changed, 7 insertions, 4 deletions

diff --git a/django/core/management/commands/makemigrations.py b/django/core/management/commands/makemigrations.py
index 2fb2d713ca..1fba1a403b 100644
--- a/django/core/management/commands/makemigrations.py
+++ b/django/core/management/commands/makemigrations.py
@@ -1,3 +1,4 @@
+import io
 import os
 import sys
 import warnings
@@ -222,7 +223,7 @@ class Command(BaseCommand):
                         # We just do this once per app
                         directory_created[app_label] = True
                     migration_string = writer.as_string()
-                    with open(writer.path, "wb") as fh:
+                    with io.open(writer.path, "w", encoding='utf-8') as fh:
                         fh.write(migration_string)
                 elif self.verbosity == 3:
                     # Alternatively, makemigrations --dry-run --verbosity 3
@@ -301,7 +302,7 @@ class Command(BaseCommand):
 
                 if not self.dry_run:
                     # Write the merge migrations file to the disk
-                    with open(writer.path, "wb") as fh:
+                    with io.open(writer.path, "w", encoding='utf-8') as fh:
                         fh.write(writer.as_string())
                     if self.verbosity > 0:
                         self.stdout.write("\nCreated new merge migration %s" % writer.path)
diff --git a/django/core/management/commands/squashmigrations.py b/django/core/management/commands/squashmigrations.py
index d9babf85f8..dacc8fe6ce 100644
--- a/django/core/management/commands/squashmigrations.py
+++ b/django/core/management/commands/squashmigrations.py
@@ -1,3 +1,5 @@
+import io
+
 from django.conf import settings
 from django.core.management.base import BaseCommand, CommandError
 from django.db import DEFAULT_DB_ALIAS, connections, migrations
@@ -162,7 +164,7 @@ class Command(BaseCommand):
 
         # Write out the new migration file
         writer = MigrationWriter(new_migration)
-        with open(writer.path, "wb") as fh:
+        with io.open(writer.path, "w", encoding='utf-8') as fh:
             fh.write(writer.as_string())
 
         if self.verbosity > 0:
diff --git a/django/db/migrations/writer.py b/django/db/migrations/writer.py
index e75f5bfdd1..df70f61eae 100644
--- a/django/db/migrations/writer.py
+++ b/django/db/migrations/writer.py
@@ -217,7 +217,7 @@ class MigrationWriter(object):
         if self.migration.initial:
             items['initial_str'] = "\n    initial = True\n"
 
-        return (MIGRATION_TEMPLATE % items).encode("utf8")
+        return MIGRATION_TEMPLATE % items
 
     @property
     def basedir(self):