Add type to chunk_size arg for update_index

CHANGELOG.txt

@@ -16,6 +16,7 @@ Changelog
  * Fix: Explorer menu no longer shows sibling pages for which the user does not have access (Mike Hearn)
  * Fix: Fixed occurences of invalid HTML across the CMS admin (Thibaud Colas)
  * Fix: Admin HTML now includes the correct `dir` attribute for the active language (Andreas Bernacca)
+ * Fix: Fix type error when using `--chunk_size` argument on `./manage.py update_index` (Seb Brown)
 
 
 2.5.1 (07.05.2019)

docs/releases/2.6.rst

@@ -30,6 +30,7 @@ Bug fixes
  * Explorer menu no longer shows sibling pages for which the user does not have access (Mike Hearn)
  * Fixed occurences of invalid HTML across the CMS admin (Thibaud Colas)
  * Admin HTML now includes the correct ``dir`` attribute for the active language (Andreas Bernacca)
+ * Fix type error when using ``--chunk_size`` argument on ``./manage.py update_index`` (Seb Brown)
 
 
 Upgrade considerations

wagtail/search/management/commands/update_index.py

@@ -103,7 +103,7 @@ class Command(BaseCommand):
             '--schema-only', action='store_true', dest='schema_only', default=False,
             help="Prevents loading any data into the index")
         parser.add_argument(
-            '--chunk_size', action='store', dest='chunk_size', default=DEFAULT_CHUNK_SIZE,
+            '--chunk_size', action='store', dest='chunk_size', default=DEFAULT_CHUNK_SIZE, type=int,
             help="Set number of records to be fetched at once for inserting into the index")
 
     def handle(self, **options):