Fixed #4833 -- Validate email addresses with localhost as domain

django/core/validators.py

@@ -78,30 +78,53 @@ def validate_integer(value):
         raise ValidationError('')
 
 
-class EmailValidator(RegexValidator):
+class EmailValidator(object):
+    message = _('Enter a valid e-mail address.')
+    code = 'invalid'
+    user_regex = re.compile(
+        r"(^[-!#$%&'*+/=?^_`{}|~0-9A-Z]+(\.[-!#$%&'*+/=?^_`{}|~0-9A-Z]+)*$"  # dot-atom
+        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
+        # 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)
+    domain_whitelist = ['localhost']
+
+    def __init__(self, message=None, code=None, whitelist=None):
+        if message is not None:
+            self.message = message
+        if code is not None:
+            self.code = code
+        if whitelist is not None:
+            self.domain_whitelist = whitelist
 
     def __call__(self, value):
-        try:
-            super(EmailValidator, self).__call__(value)
-        except ValidationError as e:
-            # Trivial case failed. Try for possible IDN domain-part
-            if value and '@' in value:
-                parts = value.split('@')
-                try:
-                    parts[-1] = parts[-1].encode('idna').decode('ascii')
-                except UnicodeError:
-                    raise e
-                super(EmailValidator, self).__call__('@'.join(parts))
-            else:
-                raise
+        value = force_text(value)
 
-email_re = re.compile(
-    r"(^[-!#$%&'*+/=?^_`{}|~0-9A-Z]+(\.[-!#$%&'*+/=?^_`{}|~0-9A-Z]+)*"  # dot-atom
-    # quoted-string, see also http://tools.ietf.org/html/rfc2822#section-3.2.5
-    r'|^"([\001-\010\013\014\016-\037!#-\[\]-\177]|\\[\001-\011\013\014\016-\177])*"'
-    r')@((?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)$)'  # domain
-    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)  # literal form, ipv4 address (SMTP 4.1.3)
-validate_email = EmailValidator(email_re, _('Enter a valid email address.'), 'invalid')
+        if not value or '@' not in value:
+            raise ValidationError(self.message, code=self.code)
+
+        user_part, domain_part = value.split('@', 1)
+
+        if not self.user_regex.match(user_part):
+            raise ValidationError(self.message, code=self.code)
+
+        if (not domain_part in self.domain_whitelist and
+                not self.domain_regex.match(domain_part)):
+            # Try for possible IDN domain-part
+            try:
+                domain_part = domain_part.encode('idna').decode('ascii')
+                if not self.domain_regex.match(domain_part):
+                    raise ValidationError(self.message, code=self.code)
+                else:
+                    return
+            except UnicodeError:
+                pass
+            raise ValidationError(self.message, code=self.code)
+
+validate_email = EmailValidator()
 
 slug_re = re.compile(r'^[-a-zA-Z0-9_]+$')
 validate_slug = RegexValidator(slug_re, _("Enter a valid 'slug' consisting of letters, numbers, underscores or hyphens."), 'invalid')

docs/ref/validators.txt

@@ -96,7 +96,7 @@ to, or in lieu of custom ``field.clean()`` methods.
 ------------------
 .. data:: validate_email
 
-    A :class:`RegexValidator` instance that ensures a value looks like an
+    An ``EmailValidator`` instance that ensures a value looks like an
     email address.
 
 ``validate_slug``

tests/modeltests/validators/tests.py

@@ -29,6 +29,8 @@ TEST_DATA = (
     (validate_email, 'example@valid-----hyphens.com', None),
     (validate_email, 'example@valid-with-hyphens.com', None),
     (validate_email, 'test@domain.with.idn.tld.उदाहरण.परीक्षा', None),
+    (validate_email, 'email@localhost', None),
+    (EmailValidator(whitelist=['localdomain']), 'email@localdomain', None),
 
     (validate_email, None, ValidationError),
     (validate_email, '', ValidationError),