From 49d07c6100034103aa3e08316f452cb0829d173c Mon Sep 17 00:00:00 2001
From: Yuval Tassa <tassa@google.com>
Date: Wed, 5 Feb 2025 05:35:36 -0800
Subject: [PATCH] Fix text edit buffer underrun.

PiperOrigin-RevId: 723474334
Change-Id: Ibff6d83d67275e6c6333a00cabe33967913dceb1
---
 src/ui/ui_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/ui/ui_main.c b/src/ui/ui_main.c
index 6cfa003b..7996c610 100644
--- a/src/ui/ui_main.c
+++ b/src/ui/ui_main.c
@@ -1106,7 +1106,7 @@ static void revealcursor(mjrRect r, mjUI* ui, const mjrContext* con) {
 
   // scan backwards
   int i = ui->editcursor;
-  while (width >= 0 && i >= ui->editscroll) {
+  while (width >= 0 && i >= ui->editscroll && i > 0) {
     i--;
     width -= con->charWidth[(unsigned char)ui->edittext[i]];
   }