Fixed #22943 -- Correctly serialize compiled regexes.

Thanks to antialiasis at gmail dot com for the patch.

1 files changed, 15 insertions, 0 deletions

diff --git a/django/db/migrations/writer.py b/django/db/migrations/writer.py
index 68f3eb50ce..dbeaae184c 100644
--- a/django/db/migrations/writer.py
+++ b/django/db/migrations/writer.py
@@ -6,6 +6,7 @@ import decimal
 import collections
 from importlib import import_module
 import os
+import re
 import sys
 import types
 
@@ -17,6 +18,9 @@ from django.utils.encoding import force_text
 from django.utils.functional import Promise
 
 
+COMPILED_REGEX_TYPE = type(re.compile(''))
+
+
 class SettingsReference(str):
     """
     Special subclass of string which actually references a current settings
@@ -344,6 +348,17 @@ class MigrationWriter(object):
             # "()", not "(,)" because (,) is invalid Python syntax.
             format = "(%s)" if len(strings) != 1 else "(%s,)"
             return format % (", ".join(strings)), imports
+        # Compiled regex
+        elif isinstance(value, COMPILED_REGEX_TYPE):
+            imports = set(["import re"])
+            regex_pattern, pattern_imports = cls.serialize(value.pattern)
+            regex_flags, flag_imports = cls.serialize(value.flags)
+            imports.update(pattern_imports)
+            imports.update(flag_imports)
+            args = [regex_pattern]
+            if value.flags:
+                args.append(regex_flags)
+            return "re.compile(%s)" % ', '.join(args), imports
         # Uh oh.
         else:
             raise ValueError("Cannot serialize: %r\nThere are some values Django cannot serialize into migration files.\nFor more, see https://docs.djangoproject.com/en/dev/topics/migrations/#migration-serializing" % value)