From 082cb79ea1bf91ec488e39b30e7178d7db515f71 Mon Sep 17 00:00:00 2001
From: Tux <write@imaginarycode.com>
Date: Wed, 13 Apr 2016 14:00:40 -0400
Subject: [PATCH] Validate that chat messages are non-blank


diff --git a/proxy/src/main/java/io/github/waterfallmc/waterfall/StringUtil.java b/proxy/src/main/java/io/github/waterfallmc/waterfall/StringUtil.java
new file mode 100644
index 0000000..940ad80
--- /dev/null
+++ b/proxy/src/main/java/io/github/waterfallmc/waterfall/StringUtil.java
@@ -0,0 +1,22 @@
+package io.github.waterfallmc.waterfall;
+
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+@NoArgsConstructor(access = AccessLevel.PRIVATE)
+public class StringUtil {
+    public static boolean isBlank(String str) {
+        if (str.isEmpty()) {
+            return true;
+        }
+
+        int l = str.length();
+        for (int i = 0; i < l; i++) {
+            if (!Character.isWhitespace(str.charAt(i))) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
diff --git a/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java b/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java
index 7565ff9..42bb2fb 100644
--- a/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java
+++ b/proxy/src/main/java/net/md_5/bungee/connection/UpstreamBridge.java
@@ -1,6 +1,7 @@
 package net.md_5.bungee.connection;
 
 import com.google.common.base.Preconditions;
+import io.github.waterfallmc.waterfall.StringUtil;
 import net.md_5.bungee.BungeeCord;
 import net.md_5.bungee.ServerConnection;
 import net.md_5.bungee.UserConnection;
@@ -109,6 +110,7 @@ public class UpstreamBridge extends PacketHandler
     public void handle(Chat chat) throws Exception
     {
         Preconditions.checkArgument( chat.getMessage().length() <= 100, "Chat message too long" ); // Mojang limit, check on updates
+        Preconditions.checkArgument(!StringUtil.isBlank(chat.getMessage()), "Chat message is empty");
 
         ServerConnection server = con.getServer();
 
-- 
2.8.3