From 7dff37e354ed04757a5e2f014aab6a4b7afe5e9b Mon Sep 17 00:00:00 2001
From: Ed Sanders <esanders@wikimedia.org>
Date: Mon, 28 Aug 2023 19:53:28 +0100
Subject: [PATCH] Show new topics subscription button on history pages

Bug: T345096
Change-Id: I5da6ac0bca900f9fe3482d247d20aaf24feb61f2
---
 includes/Hooks/HookUtils.php | 10 ++++++++--
 includes/Hooks/PageHooks.php |  2 ++
 modules/dt.init.js           |  9 ++++++++-
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/includes/Hooks/HookUtils.php b/includes/Hooks/HookUtils.php
index 7b13dbbd5..3d12d70ea 100644
--- a/includes/Hooks/HookUtils.php
+++ b/includes/Hooks/HookUtils.php
@@ -406,8 +406,14 @@ class HookUtils {
 			// Don't try to call $output->getActionName if testing for NEWTOPICTOOL as we use
 			// the hook onGetActionName to override the action for the tool on empty pages.
 			// If we tried to call it here it would set up infinite recursion (T312689)
-			$feature !== static::NEWTOPICTOOL &&
-			!in_array( $output->getActionName(), [ 'view', 'edit', 'submit' ], true )
+			$feature !== static::NEWTOPICTOOL && !(
+				in_array( $output->getActionName(), [ 'view', 'edit', 'submit' ], true ) ||
+				// Subscriptions (specifically page-level subscriptions) are available on history pages (T345096)
+				(
+					$output->getActionName() === 'history' &&
+					$feature === static::TOPICSUBSCRIPTION
+				)
+			)
 		) {
 			return false;
 		}
diff --git a/includes/Hooks/PageHooks.php b/includes/Hooks/PageHooks.php
index db81d8cfb..e88b50221 100644
--- a/includes/Hooks/PageHooks.php
+++ b/includes/Hooks/PageHooks.php
@@ -584,6 +584,8 @@ class PageHooks implements
 				'data-mw-subscribed' => $button['isSubscribed'] ? '1' : '0',
 				'href' => $button['href'],
 			];
+
+			$output->addModules( [ 'ext.discussionTools.init' ] );
 		}
 	}
 
diff --git a/modules/dt.init.js b/modules/dt.init.js
index 3a41b4451..92f71d1ba 100644
--- a/modules/dt.init.js
+++ b/modules/dt.init.js
@@ -77,11 +77,18 @@ if ( url.searchParams.get( 'dtdebug' ) ) {
 	mw.hook( 'wikipage.content' ).add( mw.dt.init );
 }
 
+var topicSubscriptions;
+
 if ( mw.config.get( 'wgCanonicalSpecialPageName' ) === 'TopicSubscriptions' ) {
-	var topicSubscriptions = require( './topicsubscriptions.js' );
+	topicSubscriptions = require( './topicsubscriptions.js' );
 	topicSubscriptions.initSpecialTopicSubscriptions();
 }
 
+if ( mw.config.get( 'wgAction' ) === 'history' ) {
+	topicSubscriptions = require( './topicsubscriptions.js' );
+	topicSubscriptions.initNewTopicsSubscription();
+}
+
 // Clean up old localStorage entries that were erroneously set with no expiration (T339042).
 // We are no longer using these keys since T329299.
 // TODO: Remove this code after a few weeks.