From 824675d072f94888ebc91d0abdbc386e3703d4dc Mon Sep 17 00:00:00 2001
From: Joakim Erdfelt <joakim.erdfelt@gmail.com>
Date: Tue, 16 Apr 2013 06:49:33 -0700
Subject: [PATCH] Guarding ExtensionStack.toString() from NPE

---
 .../common/extensions/ExtensionStack.java     | 38 +++++++++++++------
 .../common/extensions/ExtensionStackTest.java |  8 ++++
 2 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStack.java b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStack.java
index c3e266e6b1c..29450cf82a9 100644
--- a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStack.java
+++ b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStack.java
@@ -251,19 +251,35 @@ public class ExtensionStack extends ContainerLifeCycle implements IncomingFrames
     {
         StringBuilder s = new StringBuilder();
         s.append("ExtensionStack[");
-        s.append("extensions=[");
-        boolean delim = false;
-        for (Extension ext : extensions)
+        s.append("extensions=");
+        if (extensions == null)
         {
-            if (delim)
-            {
-                s.append(',');
-            }
-            s.append(ext.getName());
-            delim = true;
+            s.append("<null>");
         }
-        s.append("],incoming=").append(this.nextIncoming.getClass().getName());
-        s.append(",outgoing=").append(this.nextOutgoing.getClass().getName());
+        else
+        {
+            s.append('[');
+            boolean delim = false;
+            for (Extension ext : extensions)
+            {
+                if (delim)
+                {
+                    s.append(',');
+                }
+                if (ext == null)
+                {
+                    s.append("<null>");
+                }
+                else
+                {
+                    s.append(ext.getName());
+                }
+                delim = true;
+            }
+            s.append(']');
+        }
+        s.append(",incoming=").append((this.nextIncoming == null)?"<null>":this.nextIncoming.getClass().getName());
+        s.append(",outgoing=").append((this.nextOutgoing == null)?"<null>":this.nextOutgoing.getClass().getName());
         s.append("]");
         return s.toString();
     }
diff --git a/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStackTest.java b/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStackTest.java
index 8b2825a97ee..096dc82d2d2 100644
--- a/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStackTest.java
+++ b/jetty-websocket/websocket-common/src/test/java/org/eclipse/jetty/websocket/common/extensions/ExtensionStackTest.java
@@ -160,4 +160,12 @@ public class ExtensionStackTest
             stack.stop();
         }
     }
+
+    @Test
+    public void testToString()
+    {
+        ExtensionStack stack = createExtensionStack();
+        // Shouldn't cause a NPE.
+        LOG.debug("Shouldn't cause a NPE: {}",stack.toString());
+    }
 }