fix: #8538, go to first unread instead of last read

public/src/client/topic.js

@@ -136,7 +136,7 @@ define('forum/topic', [
 				timeout: 0,
 				type: 'info',
 				clickfn: function () {
-					navigator.scrollToIndex(parseInt(bookmark - 1, 10), true);
+					navigator.scrollToIndex(parseInt(bookmark, 10), true);
 				},
 				closefn: function () {
 					storage.removeItem('topic:' + tid + ':bookmark');
@@ -259,7 +259,7 @@ define('forum/topic', [
 					if (err) {
 						return app.alertError(err.message);
 					}
-					ajaxify.data.bookmark = index;
+					ajaxify.data.bookmark = index + 1;
 				});
 			} else {
 				storage.setItem(bookmarkKey, index);

src/topics/index.js

@@ -119,7 +119,9 @@ Topics.getTopicsByTids = async function (tids, options) {
 			topic.isOwner = topic.uid === parseInt(uid, 10);
 			topic.ignored = isIgnored[i];
 			topic.unread = !hasRead[i] && !isIgnored[i];
-			topic.bookmark = sortOldToNew ? Math.max(1, topic.postcount + 2 - bookmarks[i]) : bookmarks[i];
+			topic.bookmark = sortOldToNew ?
+				Math.max(1, topic.postcount + 2 - bookmarks[i]) :
+				Math.min(topic.postcount, bookmarks[i] + 1);
 			topic.unreplied = !topic.teaser;
 
 			topic.icons = [];