Fixed #32595 -- Fixed SchemaEditor.quote_value() crash with bytes.

django/db/backends/mysql/base.py

@@ -230,7 +230,14 @@ class DatabaseWrapper(BaseDatabaseWrapper):
 
     @async_unsafe
     def get_new_connection(self, conn_params):
-        return Database.connect(**conn_params)
+        connection = Database.connect(**conn_params)
+        # bytes encoder in mysqlclient doesn't work and was added only to
+        # prevent KeyErrors in Django < 2.0. We can remove this workaround when
+        # mysqlclient 2.1 becomes the minimal mysqlclient supported by Django.
+        # See https://github.com/PyMySQL/mysqlclient/issues/489
+        if connection.encoders.get(bytes) is bytes:
+            connection.encoders.pop(bytes)
+        return connection
 
     def init_connection_state(self):
         assignments = []

tests/backends/mysql/test_schema.py

@@ -12,6 +12,7 @@ class SchemaEditorTests(TestCase):
         tested_values = [
             ('string', "'string'"),
             ('¿Tú hablas inglés?', "'¿Tú hablas inglés?'"),
+            (b'bytes', b"'bytes'"),
             (42, '42'),
             (1.754, '1.754e0' if MySQLdb.version_info >= (1, 3, 14) else '1.754'),
             (False, b'0' if MySQLdb.version_info >= (1, 4, 0) else '0'),