From ed2d776844b66b5fe684d18033706daf1d6719c9 Mon Sep 17 00:00:00 2001
From: hneemann <helmut.neemann@arcor.de>
Date: Fri, 30 Apr 2021 09:41:00 +0200
Subject: [PATCH] fixes an issue in the telnet ByteBuffer

---
 .../java/de/neemann/digital/core/io/telnet/ByteBuffer.java  | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/main/java/de/neemann/digital/core/io/telnet/ByteBuffer.java b/src/main/java/de/neemann/digital/core/io/telnet/ByteBuffer.java
index b43ddd338..2aee42ec9 100644
--- a/src/main/java/de/neemann/digital/core/io/telnet/ByteBuffer.java
+++ b/src/main/java/de/neemann/digital/core/io/telnet/ByteBuffer.java
@@ -52,8 +52,10 @@ public class ByteBuffer {
      * deletes a byte from the tail of the buffer
      */
     synchronized public void delete() {
-        oldest = inc(oldest);
-        inBuffer--;
+        if (inBuffer > 0) {
+            oldest = inc(oldest);
+            inBuffer--;
+        }
     }
 
     /**