Re: Passing unicode to Email validator

>From c557820b95a13d847f9b20f2e084c0cc70a604a7 Mon Sep 17 00:00:00 2001
From: Leandro Lucarella <[email protected]>
Date: Wed, 15 Oct 2008 16:09:44 -0300
Subject: [PATCH] Use dnspython to support IDN when using domain resolution in Email validator

When trying to resolve a domain (via the resolve_domain option for the
Email validator), and the e-mail address is a unicode string (even when it
only contains ASCII characters) pyDNS goes crazy, and raises almost random
unicode errors. So use dnspython[1] instead, that support IDN since 2005.

This patch does some identation fixes too.

[1] http://www.dnspython.org
---
 formencode/validators.py |   55 ++++++++++++++++++++++++++-------------------
 1 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/formencode/validators.py b/formencode/validators.py
index 04587b9..4afce34 100644
--- a/formencode/validators.py
+++ b/formencode/validators.py
@@ -46,8 +46,9 @@ import cgi
 import fieldstorage
 
 try:
-    import DNS
-    DNS.DiscoverNameServers()
+    import dns.resolver
+    import dns.exception
+    from encodings import idna
     have_dns=True
 except ImportError:
     have_dns=False
@@ -1269,8 +1270,8 @@ class Email(FancyValidator):
 
     If you pass ``resolve_domain=True``, then it will try to resolve
     the domain name to make sure it's valid.  This takes longer, of
-    course.  You must have the `pyDNS <http://pydns.sf.net>`__ modules
-    installed to look up DNS (MX and A) records.
+    course.  You must have the `dnspython <http://www.dnspython.org/>`__
+    modules installed to look up DNS (MX and A) records.
 
     ::
 
@@ -1309,10 +1310,16 @@ class Email(FancyValidator):
         >>> e.to_python('test-gifGjc5/[email protected]')
         'test-gifGjc5/[email protected]'
         >>> # NOTE: If you do not have PyDNS installed this example won't work:
+        >>> e.to_python((u'test@t\u016bdali\u0146.lv')
+        u'test@t\u016bdali\u0146.lv'
         >>> e.to_python('test-uihjHT2Oh7lHgoOn0jT6HnyRXQViASWaYGFN1R+/[email protected]')
         Traceback (most recent call last):
             ...
-        Invalid: The domain of the email address does not exist (the portion after the @: thisdomaindoesnotexistithinkforsure.com)
+        Invalid: The domain of the email address does not exist (the portion afte
+        >>> e.to_python(u'test@thisdomaindoesnotexistithinkforsure\xe1.com')
+        Traceback (most recent call last):
+            ...
+        Invalid: The domain of the email address does not exist (the portion afte
         >>> e = Email(not_empty=False)
         >>> e.to_python('')
 
@@ -1341,10 +1348,10 @@ class Email(FancyValidator):
             if not have_dns:
                 import warnings
                 warnings.warn(
-                    "pyDNS <http://pydns.sf.net> is not installed on "
-                    "your system (or the DNS package cannot be found).  "
-                    "I cannot resolve domain names in addresses")
-                raise ImportError, "no module named DNS"
+                    "dnspython <http://www.dnspython.org/> is not installed "
+                    "on your system (or the dns.resolver package cannot be "
+                    "found).  I cannot resolve domain names in addresses")
+                raise ImportError, "no module named dns.resolver"
 
     def validate_python(self, value, state):
         if not value:
@@ -1364,26 +1371,28 @@ class Email(FancyValidator):
                 self.message('badUsername', state,
                              username=username),
                 value, state)
-        if not self.domainRE.search(domain):
+        idna_domain = '.'.join([idna.ToASCII(l) for l in domain.split('.')])
+        if not self.domainRE.search(idna_domain):
             raise Invalid(
                 self.message('badDomain', state,
                              domain=domain),
                 value, state)
         if self.resolve_domain:
-            assert have_dns, "pyDNS should be available"
-	    try:
-                a=DNS.DnsRequest(domain, qtype='mx').req().answers
-                if not a:
-                    a=DNS.DnsRequest(domain, qtype='a').req().answers
-                dnsdomains=[x['data'] for x in a]
-	    except (socket.error, DNS.DNSError), e:
+            assert have_dns, "dnspython should be available"
+            try:
+                try:
+                    a = dns.resolver.query(domain, 'MX')
+                except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer), e:
+                    try:
+                        a = dns.resolver.query(domain, 'A')
+                    except (dns.resolver.NXDOMAIN, dns.resolver.NoAnswer), e:
+                        raise Invalid(
+                            self.message('domainDoesNotExist', state,
+                                         domain=domain),
+                            value, state)
+            except (socket.error, dns.exception.DNSException), e:
 		raise Invalid(
-		    self.message('socketError', state, error=e),
-		    value, state)
-            if not dnsdomains:
-                raise Invalid(
-                    self.message('domainDoesNotExist', state,
-                                 domain=domain),
+                    self.message('socketError', state, error=e),
                     value, state)
 
     def _to_python(self, value, state):
-- 
1.5.6.5