From bb4aa709e67e15c57a9e536e74dc76411d4e521f Mon Sep 17 00:00:00 2001
From: Wolfsblvt <wolfsblvt@gmail.com>
Date: Tue, 30 Jul 2024 01:13:43 +0200
Subject: [PATCH] Fix "show more messages" on empty chat

- Fixes lazy loading of chat when all messages were deleted
- Fixes #2586
---
 public/script.js | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/public/script.js b/public/script.js
index f84163bae..b35d140ed 100644
--- a/public/script.js
+++ b/public/script.js
@@ -227,7 +227,7 @@ import { BulkEditOverlay, CharacterContextMenu } from './scripts/BulkEditOverlay
 import { loadFeatherlessModels, loadMancerModels, loadOllamaModels, loadTogetherAIModels, loadInfermaticAIModels, loadOpenRouterModels, loadVllmModels, loadAphroditeModels, loadDreamGenModels } from './scripts/textgen-models.js';
 import { appendFileContent, hasPendingFileAttachment, populateFileAttachment, decodeStyleTags, encodeStyleTags, isExternalMediaAllowed, getCurrentEntityId } from './scripts/chats.js';
 import { initPresetManager } from './scripts/preset-manager.js';
-import { MacrosParser, evaluateMacros } from './scripts/macros.js';
+import { MacrosParser, evaluateMacros, getLastMessageId } from './scripts/macros.js';
 import { currentUser, setUserControls } from './scripts/user.js';
 import { POPUP_RESULT, POPUP_TYPE, Popup, callGenericPopup, fixToastrForDialogs } from './scripts/popup.js';
 import { renderTemplate, renderTemplateAsync } from './scripts/templates.js';
@@ -1720,16 +1720,24 @@ export async function replaceCurrentChat() {
 }
 
 export function showMoreMessages() {
-    let messageId = Number($('#chat').children('.mes').first().attr('mesid'));
+    const firstDisplayedMesId = $('#chat').children('.mes').first().attr('mesid');
+    let messageId = Number(firstDisplayedMesId);
     let count = power_user.chat_truncation || Number.MAX_SAFE_INTEGER;
 
+    // If there are no messages displayed, or the message somehow has no mesid, we default to one higher than last message id,
+    // so the first "new" message being shown will be the last available message
+    if (!messageId) {
+        messageId = getLastMessageId() + 1;
+    }
+
     console.debug('Inserting messages before', messageId, 'count', count, 'chat length', chat.length);
     const prevHeight = $('#chat').prop('scrollHeight');
 
     while (messageId > 0 && count > 0) {
+        let newMessageId = messageId - 1;
+        addOneMessage(chat[newMessageId], { insertBefore: messageId >= chat.length ? null : messageId, scroll: false, forceId: newMessageId });
         count--;
         messageId--;
-        addOneMessage(chat[messageId], { insertBefore: messageId + 1, scroll: false, forceId: messageId });
     }
 
     if (messageId == 0) {