From 115f32171d58b2789beb1876a746faab6fa4c91c Mon Sep 17 00:00:00 2001
From: nkzawa <naoyuki.kanezawa@gmail.com>
Date: Tue, 11 Jul 2017 18:16:49 +0900
Subject: [PATCH] parser: check empty arg

---
 src/main/java/io/socket/engineio/parser/Parser.java     | 4 ++++
 src/test/java/io/socket/engineio/parser/ParserTest.java | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/src/main/java/io/socket/engineio/parser/Parser.java b/src/main/java/io/socket/engineio/parser/Parser.java
index 010ba9c..c34dce5 100644
--- a/src/main/java/io/socket/engineio/parser/Parser.java
+++ b/src/main/java/io/socket/engineio/parser/Parser.java
@@ -76,6 +76,10 @@ public class Parser {
     }
 
     public static Packet<String> decodePacket(String data, boolean utf8decode) {
+        if (data == null) {
+            return err;
+        }
+
         int type;
         try {
             type = Character.getNumericValue(data.charAt(0));
diff --git a/src/test/java/io/socket/engineio/parser/ParserTest.java b/src/test/java/io/socket/engineio/parser/ParserTest.java
index a904312..86b7c7f 100644
--- a/src/test/java/io/socket/engineio/parser/ParserTest.java
+++ b/src/test/java/io/socket/engineio/parser/ParserTest.java
@@ -156,6 +156,13 @@ public class ParserTest {
         });
     }
 
+    @Test
+    public void decodeEmptyPayload() {
+        Packet<String> p = decodePacket((String)null);
+        assertThat(p.type, is(Packet.ERROR));
+        assertThat(p.data, is(ERROR_DATA));
+    }
+
     @Test
     public void decodeBadFormat() {
         Packet<String> p = decodePacket(":::");