From b5732b90d6cd22884cde850249902abeeb11a510 Mon Sep 17 00:00:00 2001
From: Sahil Batra <sahil@zulip.com>
Date: Tue, 30 Jul 2024 19:59:31 +0530
Subject: [PATCH] create_user: Do not send reactivation event for inaccessible
 users.

---
 api_docs/changelog.md         |  5 +++++
 zerver/actions/create_user.py |  5 +++--
 zerver/openapi/zulip.yaml     | 17 +++++++++++------
 zerver/tests/test_events.py   | 16 ++++++++++++++++
 4 files changed, 35 insertions(+), 8 deletions(-)

diff --git a/api_docs/changelog.md b/api_docs/changelog.md
index c8fc2c6495..3e1412ff08 100644
--- a/api_docs/changelog.md
+++ b/api_docs/changelog.md
@@ -20,6 +20,11 @@ format used by the Zulip server that they are interacting with.
 
 ## Changes in Zulip 10.0
 
+**Feature level 303**
+
+* [`GET /events`](/api/get-events): User reactivation event is not sent
+  to users who cannot access the reactivated user anymore.
+
 **Feature level 302**
 
 * [`GET /users/{email}`](/api/get-user-by-email): Changed the `email`
diff --git a/zerver/actions/create_user.py b/zerver/actions/create_user.py
index 2801cdfd30..9b6527690a 100644
--- a/zerver/actions/create_user.py
+++ b/zerver/actions/create_user.py
@@ -37,6 +37,7 @@ from zerver.lib.users import (
     format_user_row,
     get_api_key,
     get_data_for_inaccessible_user,
+    get_user_ids_who_can_access_user,
     user_access_restricted_in_realm,
     user_profile_to_user_row,
 )
@@ -59,7 +60,7 @@ from zerver.models import (
 )
 from zerver.models.groups import SystemGroups
 from zerver.models.realm_audit_logs import AuditLogEventType
-from zerver.models.users import active_user_ids, bot_owner_user_ids, get_system_bot
+from zerver.models.users import bot_owner_user_ids, get_system_bot
 from zerver.tornado.django_api import send_event_on_commit
 
 MAX_NUM_RECENT_MESSAGES = 1000
@@ -724,7 +725,7 @@ def do_reactivate_user(user_profile: UserProfile, *, acting_user: UserProfile |
     event = dict(
         type="realm_user", op="update", person=dict(user_id=user_profile.id, is_active=True)
     )
-    send_event_on_commit(user_profile.realm, event, active_user_ids(user_profile.realm_id))
+    send_event_on_commit(user_profile.realm, event, get_user_ids_who_can_access_user(user_profile))
 
     if user_profile.is_bot:
         event = dict(
diff --git a/zerver/openapi/zulip.yaml b/zerver/openapi/zulip.yaml
index 84737117fa..bdaec6e2b2 100644
--- a/zerver/openapi/zulip.yaml
+++ b/zerver/openapi/zulip.yaml
@@ -610,13 +610,18 @@ paths:
                                     - type: object
                                       additionalProperties: false
                                       description: |
-                                        When a user is deactivated or reactivated.
+                                        When a user is deactivated or reactivated. Only users
+                                        who can access the deactivated or reactivated user
+                                        receive this event.
 
-                                        **Changes**: New in Zulip 8.0 (feature level
-                                        222). Previously the server sent a `realm_user` event with
-                                        `op` field set to `remove` when deactivating a user and a
-                                        `realm_user` event with `op` field set to `add` when
-                                        reactivating a user.
+                                        **Changes**: Prior to Zulip 10.0 (feature level 303),
+                                        event for reactivation was also sent to users who
+                                        cannot access the reactivated user.
+
+                                        New in Zulip 8.0 (feature level 222). Previously the server
+                                        sent a `realm_user` event with `op` field set to `remove`
+                                        when deactivating a user and a `realm_user` event with `op`
+                                        field set to `add` when reactivating a user.
                                       properties:
                                         user_id:
                                           type: integer
diff --git a/zerver/tests/test_events.py b/zerver/tests/test_events.py
index 090a483fa5..a8e2fb3c8d 100644
--- a/zerver/tests/test_events.py
+++ b/zerver/tests/test_events.py
@@ -3118,6 +3118,22 @@ class NormalActionsTest(BaseAction):
         check_subscription_peer_remove("events[4]", events[4])
         check_stream_delete("events[5]", events[5])
 
+        self.set_up_db_for_testing_user_access()
+        # Test that guest users receive event only
+        # if they can access the reactivated user.
+        user_profile = self.example_user("cordelia")
+        do_deactivate_user(user_profile, acting_user=None)
+
+        self.user_profile = self.example_user("polonius")
+        with self.verify_action(num_events=0, state_change_expected=False) as events:
+            do_reactivate_user(user_profile, acting_user=None)
+
+        user_profile = self.example_user("shiva")
+        do_deactivate_user(user_profile, acting_user=None)
+        with self.verify_action(num_events=1) as events:
+            do_reactivate_user(user_profile, acting_user=None)
+        check_realm_user_update("events[0]", events[0], "is_active")
+
     def test_do_deactivate_realm(self) -> None:
         realm = self.user_profile.realm