Fixed #14955 -- Made the URLValidator use a HEAD request when verifying a URL. Thanks, Claude Paroz.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15500 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/validators.py

@@ -1,4 +1,5 @@
 import re
+import urllib2
 import urlparse
 
 from django.core.exceptions import ValidationError
@@ -38,6 +39,10 @@ class RegexValidator(object):
         if not self.regex.search(smart_unicode(value)):
             raise ValidationError(self.message, code=self.code)
 
+class HeadRequest(urllib2.Request):
+    def get_method(self):
+        return "HEAD"
+
 class URLValidator(RegexValidator):
     regex = re.compile(
         r'^https?://' # http:// or https://
@@ -72,7 +77,6 @@ class URLValidator(RegexValidator):
             url = value
 
         if self.verify_exists:
-            import urllib2
             headers = {
                 "Accept": "text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5",
                 "Accept-Language": "en-us,en;q=0.5",
@@ -80,13 +84,26 @@ class URLValidator(RegexValidator):
                 "Connection": "close",
                 "User-Agent": self.user_agent,
             }
+            broken_error = ValidationError(
+                _(u'This URL appears to be a broken link.'), code='invalid_link')
             try:
-                req = urllib2.Request(url, None, headers)
+                req = HeadRequest(url, None, headers)
                 u = urllib2.urlopen(req)
             except ValueError:
                 raise ValidationError(_(u'Enter a valid URL.'), code='invalid')
+            except urllib2.HTTPError, e:
+                if e.code in (405, 501):
+                    # Try a GET request (HEAD refused)
+                    # See also: http://www.w3.org/Protocols/rfc2616/rfc2616.html
+                    try:
+                        req = urllib2.Request(url, None, headers)
+                        u = urllib2.urlopen(req)
+                    except:
+                        raise broken_error
+                else:
+                    raise broken_error
             except: # urllib2.URLError, httplib.InvalidURL, etc.
-                raise ValidationError(_(u'This URL appears to be a broken link.'), code='invalid_link')
+                raise broken_error
 
 
 def validate_integer(value):

tests/regressiontests/forms/tests/fields.py

@@ -561,6 +561,7 @@ class FieldsTests(TestCase):
         self.assertEqual(u'http://www.google.com/', f.clean('http://www.google.com')) # This will fail if there's no Internet connection
         self.assertRaisesErrorWithMessage(ValidationError, "[u'Enter a valid URL.']", f.clean, 'http://example')
         self.assertRaises(ValidationError, f.clean, 'http://www.broken.djangoproject.com') # bad domain
+        self.assertRaises(ValidationError, f.clean, 'http://qa-dev.w3.org/link-testsuite/http.php?code=405') # Method not allowed
         try:
             f.clean('http://www.broken.djangoproject.com') # bad domain
         except ValidationError, e: