From 0eea8bb4ace4761f95b5728f74b3b27c847e64b6 Mon Sep 17 00:00:00 2001
From: Prakhar Pratyush <prakhar@zulip.com>
Date: Fri, 15 Nov 2024 16:26:18 +0530
Subject: [PATCH] delete_topic: Add support for empty topic name.

---
 zerver/openapi/zulip.yaml | 7 +++++++
 zerver/views/streams.py   | 2 ++
 2 files changed, 9 insertions(+)

diff --git a/zerver/openapi/zulip.yaml b/zerver/openapi/zulip.yaml
index dac8bf6f55..621e2a719d 100644
--- a/zerver/openapi/zulip.yaml
+++ b/zerver/openapi/zulip.yaml
@@ -20451,6 +20451,13 @@ paths:
                 topic_name:
                   description: |
                     The name of the topic to delete.
+
+                    Note: When the value of `realm_empty_topic_display_name` found in
+                    the [POST /register](/api/register-queue) response is used for this
+                    parameter, it is interpreted as an empty string.
+
+                    **Changes**: Before Zulip 10.0 (feature level 334), empty string
+                    was not a valid topic name for channel messages.
                   type: string
                   example: new coffee machine
               required:
diff --git a/zerver/views/streams.py b/zerver/views/streams.py
index e095db020c..feeea02dae 100644
--- a/zerver/views/streams.py
+++ b/zerver/views/streams.py
@@ -80,6 +80,7 @@ from zerver.lib.subscription_info import gather_subscriptions
 from zerver.lib.topic import (
     get_topic_history_for_public_stream,
     get_topic_history_for_stream,
+    maybe_rename_general_chat_to_empty_topic,
     messages_for_topic,
 )
 from zerver.lib.typed_endpoint import ApiParamConfig, PathOnly, typed_endpoint
@@ -965,6 +966,7 @@ def delete_in_topic(
     topic_name: str,
 ) -> HttpResponse:
     stream, ignored_sub = access_stream_by_id(user_profile, stream_id)
+    topic_name = maybe_rename_general_chat_to_empty_topic(topic_name)
 
     messages = messages_for_topic(
         user_profile.realm_id, assert_is_not_none(stream.recipient_id), topic_name