bugdown: Use specified realm, not sender realm, for rendering.

This changes bugdown to use the realm passed in by the caller (if any)
for rendering, fixing a problem where bots such as the notification
bot would have their messages rendering using the admin realm's
settings, not the settings of the realm their messages are being sent
into.

Also adds a test for the notification bot case.

Fixes #3215.

zerver/lib/actions.py

@@ -770,6 +770,7 @@ def render_incoming_message(message, content, message_users, realm):
         rendered_content = render_markdown(
             message=message,
             content=content,
+            realm=realm,
             realm_alert_words=realm_alert_words,
             message_users=message_users,
         )

zerver/lib/bugdown/__init__.py

@@ -36,7 +36,7 @@ from zerver.lib.timeout import timeout, TimeoutExpired
 from zerver.lib.cache import (
     cache_with_key, cache_get_many, cache_set_many, NotFoundInCache)
 from zerver.lib.url_preview import preview as link_preview
-from zerver.models import Message
+from zerver.models import Message, Realm
 import zerver.lib.alert_words as alert_words
 import zerver.lib.mention as mention
 from zerver.lib.str_utils import force_text, force_str
@@ -1290,13 +1290,15 @@ def log_bugdown_error(msg):
     could cause an infinite exception loop."""
     logging.getLogger('').error(msg)
 
-def do_convert(content, realm_filters_key=None, message=None, possible_words=None):
-    # type: (Text, Optional[int], Optional[Message], Optional[Set[Text]]) -> Optional[Text]
+def do_convert(content, realm_filters_key=None, message=None, message_realm=None, possible_words=None):
+    # type: (Text, Optional[int], Optional[Message], Optional[Realm], Optional[Set[Text]]) -> Optional[Text]
     """Convert Markdown to HTML, with Zulip-specific settings and hacks."""
     from zerver.models import get_active_user_dicts_in_realm, get_active_streams, UserProfile
 
     if message:
-        maybe_update_realm_filters(message.get_realm().id)
+        if message_realm is None:
+            message_realm = message.get_realm()
+        maybe_update_realm_filters(realm_filters_key)
 
     if realm_filters_key in md_engines:
         _md_engine = md_engines[realm_filters_key]
@@ -1314,8 +1316,8 @@ def do_convert(content, realm_filters_key=None, message=None, possible_words=Non
     # Pre-fetch data from the DB that is used in the bugdown thread
     global db_data
     if message:
-        realm_users = get_active_user_dicts_in_realm(message.get_realm())
-        realm_streams = get_active_streams(message.get_realm()).values('id', 'name')
+        realm_users = get_active_user_dicts_in_realm(message_realm)
+        realm_streams = get_active_streams(message_realm).values('id', 'name')
 
         if possible_words is None:
             possible_words = set() # Set[Text]
@@ -1323,7 +1325,7 @@ def do_convert(content, realm_filters_key=None, message=None, possible_words=Non
         db_data = {'possible_words':    possible_words,
                    'full_names':        dict((user['full_name'].lower(), user) for user in realm_users),
                    'short_names':       dict((user['short_name'].lower(), user) for user in realm_users),
-                   'emoji':             message.get_realm().get_emoji(),
+                   'emoji':             message_realm.get_emoji(),
                    'stream_names':      dict((stream['name'], stream) for stream in realm_streams)}
 
     try:
@@ -1378,9 +1380,9 @@ def bugdown_stats_finish():
     bugdown_total_requests += 1
     bugdown_total_time += (time.time() - bugdown_time_start)
 
-def convert(content, realm_filters_key=None, message=None, possible_words=None):
-    # type: (Text, Optional[int], Optional[Message], Optional[Set[Text]]) -> Optional[Text]
+def convert(content, realm_filters_key=None, message=None, message_realm=None, possible_words=None):
+    # type: (Text, Optional[int], Optional[Message], Optional[Realm], Optional[Set[Text]]) -> Optional[Text]
     bugdown_stats_start()
-    ret = do_convert(content, realm_filters_key, message, possible_words)
+    ret = do_convert(content, realm_filters_key, message, message_realm, possible_words)
     bugdown_stats_finish()
     return ret

zerver/lib/message.py

@@ -20,6 +20,7 @@ from zerver.lib.timestamp import datetime_to_timestamp
 from zerver.models import (
     get_display_recipient_by_id,
     Message,
+    Realm,
     Recipient,
     Stream,
     UserProfile,
@@ -215,7 +216,7 @@ class MessageDict(object):
 
                 # It's unfortunate that we need to have side effects on the message
                 # in some cases.
-                rendered_content = render_markdown(message, content, realm_id=sender_realm_id)
+                rendered_content = render_markdown(message, content, realm=message.get_realm())
                 message.rendered_content = rendered_content
                 message.rendered_content_version = bugdown.version
                 message.save_rendered_content()
@@ -299,8 +300,8 @@ def access_message(user_profile, message_id):
     # stream in your realm, so return the message, user_message pair
     return (message, user_message)
 
-def render_markdown(message, content, realm_id=None, realm_alert_words=None, message_users=None):
-    # type: (Message, Text, Optional[int], Optional[RealmAlertWords], Set[UserProfile]) -> Text
+def render_markdown(message, content, realm=None, realm_alert_words=None, message_users=None):
+    # type: (Message, Text, Optional[Realm], Optional[RealmAlertWords], Set[UserProfile]) -> Text
     """Return HTML for given markdown. Bugdown may add properties to the
     message object such as `mentions_user_ids` and `mentions_wildcard`.
     These are only on this Django object and are not saved in the
@@ -319,9 +320,10 @@ def render_markdown(message, content, realm_id=None, realm_alert_words=None, mes
         message.alert_words = set()
         message.links_for_preview = set()
 
-        if realm_id is None:
-            realm_id = message.sender.realm_id
-        realm_filters_key = realm_id
+        if realm is None:
+            realm = message.get_realm()
+        realm_filters_key = realm.id
+
         if message.sending_client.name == "zephyr_mirror" and message.sender.realm.is_zephyr_mirror_realm:
             # Use slightly customized Markdown processor for content
             # delivered via zephyr_mirror
@@ -335,7 +337,7 @@ def render_markdown(message, content, realm_id=None, realm_alert_words=None, mes
 
     # DO MAIN WORK HERE -- call bugdown to convert
     rendered_content = bugdown.convert(content, realm_filters_key=realm_filters_key,
-                                       message=message,
+                                       message=message, message_realm=realm,
                                        possible_words=possible_words)
 
     if message is not None:

zerver/tests/test_subs.py

@@ -1298,6 +1298,46 @@ class SubscriptionAPITest(ZulipTestCase):
         expected_msg = "%s just created a new stream #**%s**." % (invitee_full_name, invite_streams[0])
         self.assertEqual(msg.content, expected_msg)
 
+    def test_successful_cross_realm_notification(self):
+        # type: () -> None
+        """
+        Calling POST /json/users/me/subscriptions in a new realm
+        should notify with a proper new stream link
+        """
+        (realm, _) = do_create_realm("testrealm", "Test Realm")
+
+        notifications_stream = Stream.objects.get(name='announce', realm=realm)
+        realm.notifications_stream = notifications_stream
+        realm.save()
+
+        invite_streams = ["cross_stream"]
+
+        user = get_user_profile_by_email("AARON@zulip.com")
+        user.realm = realm
+        user.save()
+
+        # Delete the UserProfile from the cache so the realm change will be
+        # picked up
+        cache.cache_delete(cache.user_profile_by_email_cache_key(user.email))
+
+        result = self.common_subscribe_to_streams(
+            user.email,
+            invite_streams,
+            extra_post_data=dict(
+                announce='true'
+            ),
+        )
+        self.assert_json_success(result)
+
+        msg = self.get_last_message()
+        self.assertEqual(msg.recipient.type, Recipient.STREAM)
+        self.assertEqual(msg.sender_id,
+                         get_user_profile_by_email('notification-bot@zulip.com').id)
+        stream_id = Stream.objects.latest('id').id
+        expected_rendered_msg = '<p>%s just created a new stream <a class="stream" data-stream-id="%d" href="/#narrow/stream/%s">#%s</a>.</p>' % (
+            user.full_name, stream_id, invite_streams[0], invite_streams[0])
+        self.assertEqual(msg.rendered_content, expected_rendered_msg)
+
     def test_successful_subscriptions_notifies_with_escaping(self):
         # type: () -> None
         """

zerver/views/messages.py

@@ -965,7 +965,7 @@ def render_message_backend(request, user_profile, content=REQ()):
     message.content = content
     message.sending_client = request.client
 
-    rendered_content = render_markdown(message, content, realm_id=user_profile.realm_id)
+    rendered_content = render_markdown(message, content, realm=user_profile.realm)
     return json_success({"rendered": rendered_content})
 
 @authenticated_json_post_view