From 8ddeac1234ce991fb1f34d4b18691bd91e33f33c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 29 Jan 2026 17:16:11 +0000
Subject: [PATCH] Fix LVGL object deletion issue in SetChatMessage

- Refresh child_count after deleting first_child to avoid using stale count
- Add lv_obj_is_valid() checks before accessing deleted objects
- Prevent duplicate deletion by refreshing child_count before system message deletion
- Ensures last_child validation before scrolling to it

Co-authored-by: 78 <4488133+78@users.noreply.github.com>
---
 main/display/lcd_display.cc | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/main/display/lcd_display.cc b/main/display/lcd_display.cc
index c00a8a7d..51ec7d82 100644
--- a/main/display/lcd_display.cc
+++ b/main/display/lcd_display.cc
@@ -513,19 +513,23 @@ void LcdDisplay::SetChatMessage(const char* role, const char* content) {
         lv_obj_t* last_child = lv_obj_get_child(content_, child_count - 1);
         if (first_child != nullptr) {
             lv_obj_del(first_child);
+            // Refresh child count after deletion
+            child_count = lv_obj_get_child_cnt(content_);
         }
         // Scroll to the last message immediately
-        if (last_child != nullptr) {
+        if (last_child != nullptr && lv_obj_is_valid(last_child)) {
             lv_obj_scroll_to_view_recursive(last_child, LV_ANIM_OFF);
         }
     }
     
     // Collapse system messages (if it's a system message, check if the last message is also a system message)
     if (strcmp(role, "system") == 0) {
+        // Refresh child count to get accurate count after potential deletion above
+        child_count = lv_obj_get_child_cnt(content_);
         if (child_count > 0) {
             // Get the last message container
             lv_obj_t* last_container = lv_obj_get_child(content_, child_count - 1);
-            if (last_container != nullptr && lv_obj_get_child_cnt(last_container) > 0) {
+            if (last_container != nullptr && lv_obj_is_valid(last_container) && lv_obj_get_child_cnt(last_container) > 0) {
                 // Get the bubble inside the container
                 lv_obj_t* last_bubble = lv_obj_get_child(last_container, 0);
                 if (last_bubble != nullptr) {