settings: Correctly handle passing empty anonymous group.

If empty anonymous group is passed for a setting value in
an API request, the setting is set to "Nobody" group.

zerver/views/realm.py

@@ -41,11 +41,13 @@ from zerver.lib.user_groups import (
     GroupSettingChangeRequest,
     access_user_group_for_setting,
     get_group_setting_value_for_api,
+    get_system_user_group_by_name,
     parse_group_setting_value,
     validate_group_setting_value_change,
 )
 from zerver.lib.validator import check_capped_url, check_string
 from zerver.models import Realm, RealmReactivationStatus, RealmUserDefault, UserProfile
+from zerver.models.groups import SystemGroups
 from zerver.models.realms import DigestWeekdayEnum, OrgTypeEnum
 from zerver.views.user_settings import (
     check_information_density_setting_values,
@@ -352,6 +354,7 @@ def update_realm(
             else:
                 data[k] = v
 
+    nobody_group = get_system_user_group_by_name(SystemGroups.NOBODY, user_profile.realm_id)
     for setting_name, permission_configuration in Realm.REALM_PERMISSION_GROUP_SETTINGS.items():
         expected_current_setting_value = None
         assert setting_name in req_group_setting_vars
@@ -359,10 +362,12 @@ def update_realm(
             continue
 
         setting_value = req_group_setting_vars[setting_name]
-        new_setting_value = parse_group_setting_value(setting_value.new)
+        new_setting_value = parse_group_setting_value(setting_value.new, nobody_group)
 
         if setting_value.old is not None:
-            expected_current_setting_value = parse_group_setting_value(setting_value.old)
+            expected_current_setting_value = parse_group_setting_value(
+                setting_value.old, nobody_group
+            )
 
         current_value = getattr(realm, setting_name)
         current_setting_api_value = get_group_setting_value_for_api(current_value)

zerver/views/streams.py

@@ -93,6 +93,7 @@ from zerver.lib.user_groups import (
     access_user_group_for_setting,
     get_group_setting_value_for_api,
     get_role_based_system_groups_dict,
+    get_system_user_group_by_name,
     parse_group_setting_value,
     validate_group_setting_value_change,
 )
@@ -100,6 +101,7 @@ from zerver.lib.user_topics import get_users_with_user_topic_visibility_policy
 from zerver.lib.users import access_bot_by_id, bulk_access_users_by_email, bulk_access_users_by_id
 from zerver.lib.utils import assert_is_not_none
 from zerver.models import Realm, Stream, UserMessage, UserProfile, UserTopic
+from zerver.models.groups import SystemGroups
 from zerver.models.users import get_system_bot
 
 
@@ -393,6 +395,7 @@ def update_stream_backend(
             check_stream_name_available(user_profile.realm, new_name)
         do_rename_stream(stream, new_name, user_profile)
 
+    nobody_group = get_system_user_group_by_name(SystemGroups.NOBODY, user_profile.realm_id)
     request_settings_dict = locals()
     for setting_name, permission_configuration in Stream.stream_permission_group_settings.items():
         assert setting_name in request_settings_dict
@@ -400,11 +403,13 @@ def update_stream_backend(
             continue
 
         setting_value = request_settings_dict[setting_name]
-        new_setting_value = parse_group_setting_value(setting_value.new)
+        new_setting_value = parse_group_setting_value(setting_value.new, nobody_group)
 
         expected_current_setting_value = None
         if setting_value.old is not None:
-            expected_current_setting_value = parse_group_setting_value(setting_value.old)
+            expected_current_setting_value = parse_group_setting_value(
+                setting_value.old, nobody_group
+            )
 
         current_value = getattr(stream, setting_name)
         current_setting_api_value = get_group_setting_value_for_api(current_value)
@@ -618,7 +623,11 @@ def add_subscriptions_backend(
         assert setting_name in request_settings_dict
         if request_settings_dict[setting_name] is not None:
             setting_request_value = request_settings_dict[setting_name]
-            setting_value = parse_group_setting_value(setting_request_value)
+            if system_groups_name_dict is None:
+                system_groups_name_dict = get_role_based_system_groups_dict(realm)
+            setting_value = parse_group_setting_value(
+                setting_request_value, system_groups_name_dict[SystemGroups.NOBODY]
+            )
             group_settings_map[setting_name] = access_user_group_for_setting(
                 setting_value,
                 user_profile,

zerver/views/user_groups.py

@@ -33,6 +33,7 @@ from zerver.lib.user_groups import (
     get_direct_memberships_of_users,
     get_group_setting_value_for_api,
     get_subgroup_ids,
+    get_system_user_group_by_name,
     get_user_group_direct_member_ids,
     get_user_group_member_ids,
     is_user_in_group,
@@ -43,6 +44,7 @@ from zerver.lib.user_groups import (
 )
 from zerver.lib.users import access_user_by_id, user_ids_to_users
 from zerver.models import NamedUserGroup, UserProfile
+from zerver.models.groups import SystemGroups
 from zerver.models.users import get_system_bot
 from zerver.views.streams import compose_views
 
@@ -71,12 +73,15 @@ def add_user_group(
 
     group_settings_map = {}
     request_settings_dict = locals()
+    nobody_group = get_system_user_group_by_name(SystemGroups.NOBODY, user_profile.realm_id)
     for setting_name, permission_config in NamedUserGroup.GROUP_PERMISSION_SETTINGS.items():
         if setting_name not in request_settings_dict:  # nocoverage
             continue
 
         if request_settings_dict[setting_name] is not None:
-            setting_value = parse_group_setting_value(request_settings_dict[setting_name])
+            setting_value = parse_group_setting_value(
+                request_settings_dict[setting_name], nobody_group
+            )
             setting_value_group = access_user_group_for_setting(
                 setting_value,
                 user_profile,
@@ -159,6 +164,7 @@ def edit_user_group(
         do_update_user_group_description(user_group, description, acting_user=user_profile)
 
     request_settings_dict = locals()
+    nobody_group = get_system_user_group_by_name(SystemGroups.NOBODY, user_profile.realm_id)
     for setting_name, permission_config in NamedUserGroup.GROUP_PERMISSION_SETTINGS.items():
         if setting_name not in request_settings_dict:  # nocoverage
             continue
@@ -167,11 +173,13 @@ def edit_user_group(
             continue
 
         setting_value = request_settings_dict[setting_name]
-        new_setting_value = parse_group_setting_value(setting_value.new)
+        new_setting_value = parse_group_setting_value(setting_value.new, nobody_group)
 
         expected_current_setting_value = None
         if setting_value.old is not None:
-            expected_current_setting_value = parse_group_setting_value(setting_value.old)
+            expected_current_setting_value = parse_group_setting_value(
+                setting_value.old, nobody_group
+            )
 
         current_value = getattr(user_group, setting_name)
         current_setting_api_value = get_group_setting_value_for_api(current_value)