Allow disabling gravatar with WAGTAIL_GRAVATAR_PROVIDER_URL=None. Fixes #1286

docs/advanced_topics/settings.rst

@@ -235,7 +235,7 @@ Allows the default ``LoginForm`` to be extended with extra fields.
 
   WAGTAIL_GRAVATAR_PROVIDER_URL = '//www.gravatar.com/avatar'
 
-Allows to set your own Gravatar-like URL or alternatives like robohash.org
+If a user has not uploaded a profile picture, Wagtail will look for an avatar linked to their email address on gravatar.com. This setting allows you to specify an alternative provider such as like robohash.org, or can be set to ``None`` to disable the use of remote avatars completely.
 
 
 Images

wagtail/users/utils.py

@@ -1,5 +1,6 @@
 import hashlib
 from django.conf import settings
+from django.contrib.staticfiles.templatetags.staticfiles import static
 from django.utils.http import urlencode
 
 from wagtail.core.compat import AUTH_USER_APP_LABEL, AUTH_USER_MODEL_NAME
@@ -25,10 +26,13 @@ def user_can_delete_user(current_user, user_to_delete):
 def get_gravatar_url(email, size=50):
     default = "mm"
     size = int(size) * 2  # requested at retina size by default and scaled down at point of use with css
-    gravatar_provider_url = getattr(settings, 'WAGTAIL_GRAVATAR_PROVIDER_URL', '//www.gravatar.com/avatar').rstrip('/')
+    gravatar_provider_url = getattr(settings, 'WAGTAIL_GRAVATAR_PROVIDER_URL', '//www.gravatar.com/avatar')
+
+    if gravatar_provider_url is None:
+        return static('wagtailadmin/images/default-user-avatar.png')
 
     gravatar_url = "{gravatar_provider_url}/{hash}?{params}".format(
-        gravatar_provider_url=gravatar_provider_url,
+        gravatar_provider_url=gravatar_provider_url.rstrip('/'),
         hash=hashlib.md5(email.lower().encode('utf-8')).hexdigest(),
         params=urlencode({'s': size, 'd': default})
     )