From f4c9324adbd503dca610988db65900d417981999 Mon Sep 17 00:00:00 2001
From: DRC <information@virtualgl.org>
Date: Wed, 1 May 2024 13:00:58 -0400
Subject: [PATCH] Viewer: Truncate overly long conn. history strings

Java Preferences values cannot be more than Preferences.MAX_VALUE_LENGTH
(usually 8192) characters in length.  Attempting to store a longer
string into a Preferences node results in an IllegalArgumentException.

Fixes #410
---
 java/com/turbovnc/vncviewer/ServerDialog.java | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/java/com/turbovnc/vncviewer/ServerDialog.java b/java/com/turbovnc/vncviewer/ServerDialog.java
index 8a5c873c1..f0dad580c 100644
--- a/java/com/turbovnc/vncviewer/ServerDialog.java
+++ b/java/com/turbovnc/vncviewer/ServerDialog.java
@@ -1,4 +1,5 @@
-/* Copyright (C) 2012-2015, 2018, 2020 D. R. Commander.  All Rights Reserved.
+/* Copyright (C) 2012-2015, 2018, 2020, 2024 D. R. Commander.
+ *                                           All Rights Reserved.
  * Copyright (C) 2011-2013 Brian P. Hinz
  * Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
  *
@@ -26,6 +27,7 @@
 import javax.swing.border.*;
 import javax.swing.WindowConstants.*;
 import java.util.*;
+import java.util.prefs.Preferences;
 
 import com.turbovnc.rdr.*;
 import com.turbovnc.rfb.*;
@@ -246,7 +248,16 @@ private boolean commit() {
           sb.append(str);
         }
       }
-      UserPreferences.set("ServerDialog", "history", sb.toString());
+      String history = sb.toString();
+      if (history.length() > Preferences.MAX_VALUE_LENGTH) {
+        int lastComma =
+          history.lastIndexOf(',', Preferences.MAX_VALUE_LENGTH);
+        if (lastComma <= 0)
+          history = "";
+        else
+          history = history.substring(0, lastComma);
+      }
+      UserPreferences.set("ServerDialog", "history", history);
       UserPreferences.save("ServerDialog");
 
     } catch (Exception e) {