https://github.com/Simsys/qhexedit2/pull/139
From d314aab25eeab0db131fc87f20daf7c4ad587ee2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=AF=B7=E5=8F=AB=E6=88=91=E8=88=B9=E9=95=BF?=
 <38233142+thinkSJ@users.noreply.github.com>
Date: Sat, 13 Nov 2021 18:35:25 +0800
Subject: [PATCH] Update qhexedit.cpp

crashed when press ctrl alt keys....
---
 src/qhexedit.cpp | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/qhexedit.cpp b/src/qhexedit.cpp
index d7e532c..4137192 100644
--- a/src/qhexedit.cpp
+++ b/src/qhexedit.cpp
@@ -766,11 +766,15 @@ void QHexEdit::keyPressEvent(QKeyEvent *event)
             (QApplication::keyboardModifiers() == Qt::GroupSwitchModifier))
         {
             /* Hex and ascii input */
-            int key;
-            if (_editAreaIsAscii)
-                key = (uchar)event->text().at(0).toLatin1();
-            else
-                key = int(event->text().at(0).toLower().toLatin1());
+            int key = 0;
+            QString text = event->text();
+            if (!text.isEmpty())
+            {
+                if (_editAreaIsAscii)
+                    key = (uchar)text.at(0).toLatin1();
+                else
+                    key = int(text.at(0).toLower().toLatin1());
+            }
 
             if ((((key >= '0' && key <= '9') || (key >= 'a' && key <= 'f')) && _editAreaIsAscii == false)
                 || (key >= ' ' && _editAreaIsAscii))