#37 fix signed byte type math

[fanfix.git] / src / jexer / net / TelnetInputStream.java

diff --git a/src/jexer/net/TelnetInputStream.java b/src/jexer/net/TelnetInputStream.java
index 9ae77476de7d5d39305ce356149d58494fd6e2d3..ac010e8f0ab3db06f9c5a038e0ae2464ec209216 100644 (file)
--- a/src/jexer/net/TelnetInputStream.java
+++ b/src/jexer/net/TelnetInputStream.java
@@ -3,7 +3,7 @@
  *
  * The MIT License (MIT)
  *
- * Copyright (C) 2017 Kevin Lamonte
+ * Copyright (C) 2019 Kevin Lamonte
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -40,8 +40,7 @@ import static jexer.net.TelnetSocket.*;
 /**
  * TelnetInputStream works with TelnetSocket to perform the telnet protocol.
  */
-public final class TelnetInputStream extends InputStream
-        implements SessionInfo {
+public class TelnetInputStream extends InputStream implements SessionInfo {
 
     // ------------------------------------------------------------------------
     // Constants --------------------------------------------------------------
@@ -927,25 +926,41 @@ public final class TelnetInputStream extends InputStream
                 if (subnegBuffer.get(i) == (byte)TELNET_IAC) {
                     i++;
                 }
-                windowWidth = subnegBuffer.get(i) * 256;
+                int width = subnegBuffer.get(i);
+                if (width < 0) {
+                    width += 256;
+                }
+                windowWidth = width * 256;
 
                 i++;
                 if (subnegBuffer.get(i) == (byte)TELNET_IAC) {
                     i++;
                 }
-                windowWidth += subnegBuffer.get(i);
+                width = subnegBuffer.get(i);
+                windowWidth += width;
+                if (width < 0) {
+                    windowWidth += 256;
+                }
 
                 i++;
                 if (subnegBuffer.get(i) == (byte)TELNET_IAC) {
                     i++;
                 }
-                windowHeight = subnegBuffer.get(i) * 256;
+                int height = subnegBuffer.get(i);
+                if (height < 0) {
+                    height += 256;
+                }
+                windowHeight = height * 256;
 
                 i++;
                 if (subnegBuffer.get(i) == (byte)TELNET_IAC) {
                     i++;
                 }
-                windowHeight += subnegBuffer.get(i);
+                height = subnegBuffer.get(i);
+                windowHeight += height;
+                if (height < 0) {
+                    windowHeight += 256;
+                }
             }
             break;