invitations: Avoid adding to notifications stream unconditionally.

Adding invited users to the notifications stream unconditionally isn't
a correct behaviour for guest users, where the previous behavior of
including the notifications stream no longer makes sense. Therefore,
while inviting a new user, the notifications stream is listed along
with other streams with a message "recieves notifications for new
streams" in order to distinguish it from other streams.

Fixes #13645.

static/js/invite.js

@@ -123,20 +123,20 @@ function generate_multiuse_invite() {
 }
 
 exports.get_invite_streams = function () {
-    const streams = _.filter(stream_data.get_invite_stream_data(), function (stream) {
-        const is_notifications_stream = stream.name === page_params.notifications_stream;
-        // You can't actually elect to invite someone to the
-        // notifications stream. We won't even show it as a choice unless
-        // it's the only stream you have, or if you've made it private.
-        return stream_data.subscribed_streams().length === 1 ||
-            !is_notifications_stream ||
-            is_notifications_stream && stream.is_invite_only;
-    });
+    const streams = stream_data.get_invite_stream_data();
+
+    function compare_streams(a, b) {
+        return a.name.localeCompare(b.name);
+    }
+    streams.sort(compare_streams);
     return streams;
 };
 
 function update_subscription_checkboxes() {
-    const data = {streams: exports.get_invite_streams()};
+    const data = {
+        streams: exports.get_invite_streams(),
+        notifications_stream: page_params.notifications_stream,
+    };
     const html = render_invite_subscription(data);
     $('#streams_to_add').html(html);
 }

static/templates/invite_subscription.hbs

@@ -11,7 +11,11 @@
           {{#if default_stream}}checked="checked"{{/if}} />
         <span></span>
         {{#if invite_only}}<i class="fa fa-lock" aria-hidden="true"></i>{{/if}}
+        {{#if (eq name ../notifications_stream)}}
+        #{{name}} <i>({{t 'receives new stream notifications' }})</i>
+        {{else}}
         #{{name}}
+        {{/if}}
     </label>
     {{/each}}
 </div>

zerver/tests/test_signup.py

@@ -891,27 +891,6 @@ class InviteUserTest(InviteUserBase):
         self.assertTrue(find_key_by_email(email2))
         self.check_sent_emails([email, email2])
 
-    def test_successful_invite_user_with_notifications_stream(self) -> None:
-        """
-        A call to /json/invites with valid parameters unconditionally
-        subscribes the invitee to the notifications stream if it exists and is
-        public.
-        """
-        realm = get_realm('zulip')
-        notifications_stream = get_stream('Verona', realm)
-        realm.notifications_stream_id = notifications_stream.id
-        realm.save()
-
-        self.login(self.example_email("hamlet"))
-        invitee = 'alice-test@zulip.com'
-        self.assert_json_success(self.invite(invitee, ['Denmark']))
-        self.assertTrue(find_key_by_email(invitee))
-        self.check_sent_emails([invitee])
-
-        prereg_user = PreregistrationUser.objects.get(email=invitee)
-        stream_ids = [stream.id for stream in prereg_user.streams.all()]
-        self.assertTrue(notifications_stream.id in stream_ids)
-
     def test_invite_user_signup_initial_history(self) -> None:
         """
         Test that a new user invited to a stream receives some initial

zerver/views/invite.py

@@ -37,12 +37,6 @@ def invite_users_backend(request: HttpRequest, user_profile: UserProfile,
 
     invitee_emails = get_invitee_emails_set(invitee_emails_raw)
 
-    # We unconditionally sub you to the notifications stream if it
-    # exists and is public.
-    notifications_stream = user_profile.realm.notifications_stream  # type: Optional[Stream]
-    if notifications_stream and not notifications_stream.invite_only:
-        stream_ids.append(notifications_stream.id)
-
     streams = []  # type: List[Stream]
     for stream_id in stream_ids:
         try: