From 9fc5eb2af8b1bc93109ff66936fdaa6d2ae851bb Mon Sep 17 00:00:00 2001
From: Joakim Erdfelt <joakim.erdfelt@gmail.com>
Date: Thu, 11 Apr 2019 07:17:00 -0500
Subject: [PATCH] Issue #3545 - NPE in HttpOutput with print("")

Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>
---
 .../org/eclipse/jetty/server/HttpOutput.java  |  3 +-
 .../eclipse/jetty/server/ResponseTest.java    | 61 ++++++++++---------
 2 files changed, 34 insertions(+), 30 deletions(-)

diff --git a/jetty-server/src/main/java/org/eclipse/jetty/server/HttpOutput.java b/jetty-server/src/main/java/org/eclipse/jetty/server/HttpOutput.java
index 30e65225eea..8d62dcfa022 100644
--- a/jetty-server/src/main/java/org/eclipse/jetty/server/HttpOutput.java
+++ b/jetty-server/src/main/java/org/eclipse/jetty/server/HttpOutput.java
@@ -31,7 +31,6 @@ import java.nio.charset.CodingErrorAction;
 import java.util.ResourceBundle;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
-
 import javax.servlet.RequestDispatcher;
 import javax.servlet.ServletOutputStream;
 import javax.servlet.ServletRequest;
@@ -731,7 +730,7 @@ public class HttpOutput extends ServletOutputStream implements Runnable
                     else
                         continue;
             }
-            else if (crlf.hasRemaining())
+            else if (crlf != null && crlf.hasRemaining())
             {
                 result = encoder.encode(crlf, out, true);
                 if (result.isUnderflow())
diff --git a/jetty-server/src/test/java/org/eclipse/jetty/server/ResponseTest.java b/jetty-server/src/test/java/org/eclipse/jetty/server/ResponseTest.java
index ebf60e994ba..2dbdbc6a768 100644
--- a/jetty-server/src/test/java/org/eclipse/jetty/server/ResponseTest.java
+++ b/jetty-server/src/test/java/org/eclipse/jetty/server/ResponseTest.java
@@ -18,22 +18,6 @@
 
 package org.eclipse.jetty.server;
 
-import static java.nio.charset.StandardCharsets.UTF_8;
-import static org.hamcrest.CoreMatchers.allOf;
-import static org.hamcrest.MatcherAssert.assertThat;
-import static org.hamcrest.Matchers.contains;
-import static org.hamcrest.Matchers.containsInAnyOrder;
-import static org.hamcrest.Matchers.containsString;
-import static org.hamcrest.Matchers.is;
-import static org.hamcrest.Matchers.not;
-import static org.hamcrest.Matchers.nullValue;
-import static org.hamcrest.Matchers.startsWith;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertNotNull;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-import static org.junit.jupiter.api.Assertions.assertTrue;
-
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.LineNumberReader;
@@ -50,7 +34,6 @@ import java.util.Collections;
 import java.util.Enumeration;
 import java.util.Iterator;
 import java.util.Locale;
-
 import javax.servlet.ServletException;
 import javax.servlet.ServletOutputStream;
 import javax.servlet.http.Cookie;
@@ -87,6 +70,22 @@ import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.hamcrest.CoreMatchers.allOf;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.contains;
+import static org.hamcrest.Matchers.containsInAnyOrder;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.nullValue;
+import static org.hamcrest.Matchers.startsWith;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
 public class ResponseTest
 {
 
@@ -579,24 +578,30 @@ public class ResponseTest
         assertEquals("foo2/bar2;charset=utf-8", response.getContentType());
     }
 
+    @Test
+    public void testPrint_Empty() throws Exception
+    {
+        Response response = getResponse();
+        response.setCharacterEncoding(UTF_8.name());
+
+        try(ServletOutputStream outputStream = response.getOutputStream())
+        {
+            outputStream.print("ABC");
+            outputStream.print("");
+            outputStream.println();
+            outputStream.flush();
+        }
+
+        String expected = "ABC\r\n";
+        assertEquals(expected,BufferUtil.toString(_content, UTF_8));
+    }
 
     @Test
     public void testPrintln() throws Exception
     {
         Response response = getResponse();
-        Request request = response.getHttpChannel().getRequest();
-
-        SessionHandler session_handler = new SessionHandler();
-        session_handler.setServer(_server);
-        session_handler.setUsingCookies(true);
-        session_handler.start();
-        request.setSessionHandler(session_handler);
-        HttpSession session = request.getSession(true);
         response.setCharacterEncoding(UTF_8.name());
 
-        assertThat(session,not(nullValue()));
-        assertTrue(session.isNew());
-
         String expected = "";
         response.getOutputStream().print("ABC");
         expected += "ABC";