Fixed #12027 -- Fixed EmailValidator to reject a trailing dot.

Thanks Klas H for the report and claudep for the patch.

django/core/validators.py

@@ -89,7 +89,7 @@ class EmailValidator(object):
         r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\[\001-\011\013\014\016-\177])*"$)', # quoted-string
         re.IGNORECASE)
     domain_regex = re.compile(
-        r'(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}|[A-Z0-9-]{2,})\.?$'  # domain
+        r'(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}|[A-Z0-9-]{2,})$'  # domain
         # literal form, ipv4 address (SMTP 4.1.3)
         r'|^\[(25[0-5]|2[0-4]\d|[0-1]?\d?\d)(\.(25[0-5]|2[0-4]\d|[0-1]?\d?\d)){3}\]$',
         re.IGNORECASE)

tests/validators/tests.py

@@ -56,6 +56,7 @@ TEST_DATA = (
     # Quoted-string format (CR not allowed)
     (validate_email, '"\\\011"@here.com', None),
     (validate_email, '"\\\012"@here.com', ValidationError),
+    (validate_email, 'trailingdot@shouldfail.com.', ValidationError),
 
     (validate_slug, 'slug-ok', None),
     (validate_slug, 'longer-slug-still-ok', None),