From 3d8e96491bb5a228b260e76c1bc9b16d8e960db4 Mon Sep 17 00:00:00 2001
From: Reto Brunner <reto@slightlybroken.com>
Date: Mon, 9 Feb 2026 08:08:15 +0100
Subject: [PATCH 1/2] topic: display topic when no arguments are given

That's what the help says that we do, so do it.

Fixes: https://github.com/thelounge/thelounge/issues/5026
---
 server/plugins/inputs/topic.ts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/server/plugins/inputs/topic.ts b/server/plugins/inputs/topic.ts
index 5fb76994..15a1be4e 100644
--- a/server/plugins/inputs/topic.ts
+++ b/server/plugins/inputs/topic.ts
@@ -19,6 +19,14 @@ const input: PluginInputHandler = function ({irc}, chan, cmd, args) {
 		return;
 	}
 
+	const cleanArgs = args.map((s) => s.trim()).filter((s) => s !== "");
+
+	if (cleanArgs.length === 0) {
+		irc.raw("TOPIC", chan.name);
+		return;
+	}
+
+	// we use the non trimmed args here, the user may have added white space on purpose
 	irc.setTopic(chan.name, args.join(" "));
 	return true;
 };

From 91fb1ee343a733c0a3373a953e0ef46a646db884 Mon Sep 17 00:00:00 2001
From: Reto Brunner <reto@slightlybroken.com>
Date: Mon, 9 Feb 2026 08:16:27 +0100
Subject: [PATCH 2/2] add cleartopic command

Fixes: https://github.com/thelounge/thelounge/issues/4687
---
 client/components/Windows/Help.vue      | 9 +++++++++
 server/plugins/inputs/topic.ts          | 7 ++++++-
 server/types/modules/irc-framework.d.ts | 2 ++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/client/components/Windows/Help.vue b/client/components/Windows/Help.vue
index d0715a2e..e10adf41 100644
--- a/client/components/Windows/Help.vue
+++ b/client/components/Windows/Help.vue
@@ -793,6 +793,15 @@
 				</div>
 			</div>
 
+			<div class="help-item">
+				<div class="subject">
+					<code>/cleartopic</code>
+				</div>
+				<div class="description">
+					<p>Clear the topic in the current channel.</p>
+				</div>
+			</div>
+
 			<div class="help-item">
 				<div class="subject">
 					<code>/unban nick</code>
diff --git a/server/plugins/inputs/topic.ts b/server/plugins/inputs/topic.ts
index 15a1be4e..9b890ac2 100644
--- a/server/plugins/inputs/topic.ts
+++ b/server/plugins/inputs/topic.ts
@@ -4,7 +4,7 @@ import Msg from "../../models/msg";
 import {MessageType} from "../../../shared/types/msg";
 import {ChanType} from "../../../shared/types/chan";
 
-const commands = ["topic"];
+const commands = ["topic", "cleartopic"];
 
 const input: PluginInputHandler = function ({irc}, chan, cmd, args) {
 	if (chan.type !== ChanType.CHANNEL) {
@@ -19,6 +19,11 @@ const input: PluginInputHandler = function ({irc}, chan, cmd, args) {
 		return;
 	}
 
+	if (cmd === "cleartopic") {
+		irc.clearTopic(chan.name);
+		return;
+	}
+
 	const cleanArgs = args.map((s) => s.trim()).filter((s) => s !== "");
 
 	if (cleanArgs.length === 0) {
diff --git a/server/types/modules/irc-framework.d.ts b/server/types/modules/irc-framework.d.ts
index ef9f82df..2e8062af 100644
--- a/server/types/modules/irc-framework.d.ts
+++ b/server/types/modules/irc-framework.d.ts
@@ -206,6 +206,8 @@ declare module "irc-framework" {
 
 		setTopic(channel: string, newTopic: string): void;
 
+		clearTopic(channel: string): void;
+
 		ctcpRequest(target: string, type: string, ...params: Array<string>): void;
 
 		ctcpResponse(target: string, type: string, ...params: Array<string>): void;