From c2af272e7bed37082aa524ab938c3dc6f4db0160 Mon Sep 17 00:00:00 2001
From: Dominik Downarowicz <dominik.downarowicz@sonepar.at>
Date: Tue, 15 Mar 2022 22:50:29 +0100
Subject: [PATCH] Check if connection is available

---
 .../java/at/downardo/j3270Server/Telnet.java  | 70 +++++++++----------
 1 file changed, 35 insertions(+), 35 deletions(-)

diff --git a/src/main/java/at/downardo/j3270Server/Telnet.java b/src/main/java/at/downardo/j3270Server/Telnet.java
index bbc6be6..d862f9f 100644
--- a/src/main/java/at/downardo/j3270Server/Telnet.java
+++ b/src/main/java/at/downardo/j3270Server/Telnet.java
@@ -139,44 +139,44 @@ public static int[] TelnetRead(BufferedInputStream in, int[] buf) throws IOExcep
 		int state = NORMAL;
 		int n = 0;		
 		while(n <= (buf.length-1)) {
-			int bufRead = in.read();
-			
-			
-			
-			if(bufRead == 0) {
-				continue;
-			}
-			
-			
-			switch(state) {
-			case NORMAL:
-				if(bufRead == IAC) {
-					state = COMMAND;
-				}else {
-					buf[n] = bufRead;
-					n++;
+			if(in.available() > 0) {
+				int bufRead = in.read();
+				
+				if(bufRead == 0) {
+					continue;
 				}
-				break;
-			case COMMAND:
-				if(bufRead == 0xff) {
-					buf[n] = 0xff;
+				
+				
+				switch(state) {
+				case NORMAL:
+					if(bufRead == IAC) {
+						state = COMMAND;
+					}else {
+						buf[n] = bufRead;
+						n++;
+					}
+					break;
+				case COMMAND:
+					if(bufRead == 0xff) {
+						buf[n] = 0xff;
+						
+						n++;
+						state = NORMAL;
+					}else if(bufRead == SB) {
+						state = SUBNEG;
+					}else {
+						state = NORMAL;
+					}
+					break;
+				case SUBNEG:
+					if(bufRead == SE) {
+						state = NORMAL;
+					}else {
+						//remain in subnegotiation consumin bytes until we get SE
+					}
+					break;
 					
-					n++;
-					state = NORMAL;
-				}else if(bufRead == SB) {
-					state = SUBNEG;
-				}else {
-					state = NORMAL;
 				}
-				break;
-			case SUBNEG:
-				if(bufRead == SE) {
-					state = NORMAL;
-				}else {
-					//remain in subnegotiation consumin bytes until we get SE
-				}
-				break;
-				
 			}
 			
 		}