8339384: Unintentional IOException in jdk.jdi module when JDWP end of…

… stream occurs

Reviewed-by: kevinw
Backport-of: 2305d18

src/jdk.jdi/share/classes/com/sun/tools/jdi/TargetVM.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -123,8 +123,9 @@ public void run() {
                 byte b[] = connection.readPacket();
                 if (b.length == 0) {
                     done = true;
+                } else {
+                    p = Packet.fromByteArray(b);
                 }
-                p = Packet.fromByteArray(b);
             } catch (IOException e) {
                 done = true;
             }