From 176e58d0c4e7e3d23c583093aed1a45de81ea405 Mon Sep 17 00:00:00 2001
From: gregw <gregw@webtide.com>
Date: Wed, 23 Dec 2020 12:34:27 +0100
Subject: [PATCH] Fix #5835 Durable Filters, Servlets and Listeners

Update WebSocketUpgradeFilter to have durable configuration.
---
 .../server/WebSocketUpgradeFilter.java        | 40 ++++++++++---------
 1 file changed, 22 insertions(+), 18 deletions(-)

diff --git a/jetty-websocket/websocket-server/src/main/java/org/eclipse/jetty/websocket/server/WebSocketUpgradeFilter.java b/jetty-websocket/websocket-server/src/main/java/org/eclipse/jetty/websocket/server/WebSocketUpgradeFilter.java
index b691ab313e14..9d25582b02a1 100644
--- a/jetty-websocket/websocket-server/src/main/java/org/eclipse/jetty/websocket/server/WebSocketUpgradeFilter.java
+++ b/jetty-websocket/websocket-server/src/main/java/org/eclipse/jetty/websocket/server/WebSocketUpgradeFilter.java
@@ -20,6 +20,7 @@
 
 import java.io.IOException;
 import java.util.EnumSet;
+import java.util.Objects;
 import javax.servlet.DispatcherType;
 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
@@ -131,12 +132,12 @@ public static WebSocketUpgradeFilter configureContext(ServletContext context) th
 
     private NativeWebSocketConfiguration configuration;
     private String instanceKey;
-    private boolean localConfiguration = false;
+    private boolean durableConfiguration = false;
+    private boolean managedConfiguration = false;
     private boolean alreadySetToAttribute = false;
 
     public WebSocketUpgradeFilter()
     {
-        // do nothing
     }
 
     public WebSocketUpgradeFilter(WebSocketServerFactory factory)
@@ -146,6 +147,7 @@ public WebSocketUpgradeFilter(WebSocketServerFactory factory)
 
     public WebSocketUpgradeFilter(NativeWebSocketConfiguration configuration)
     {
+        durableConfiguration = configuration != null;
         this.configuration = configuration;
     }
 
@@ -182,14 +184,17 @@ public void destroy()
     {
         try
         {
-            // We must clear out the configuration as the configuration is cleared on restart.
             NativeWebSocketConfiguration config = configuration;
-            boolean localConfig = localConfiguration;
-            configuration = null;
-            localConfiguration = false;
-            alreadySetToAttribute = false;
-            if (localConfig)
+            if (!durableConfiguration)
+                configuration = null;
+
+            boolean managed = managedConfiguration;
+            managedConfiguration = false;
+            if (managed)
+            {
                 config.stop();
+            }
+            alreadySetToAttribute = false;
         }
         catch (Exception e)
         {
@@ -332,7 +337,14 @@ public void init(FilterConfig config) throws ServletException
                 configurationKey = NativeWebSocketConfiguration.class.getName();
             }
 
-            if (configuration == null)
+            if (durableConfiguration)
+            {
+                Objects.requireNonNull(this.configuration);
+                // We have a NativeWebSocketConfiguration already present, make sure it exists on the ServletContext
+                config.getServletContext().setAttribute(configurationKey, this.configuration);
+
+            }
+            else
             {
                 this.configuration = (NativeWebSocketConfiguration)config.getServletContext().getAttribute(configurationKey);
                 if (this.configuration == null)
@@ -342,18 +354,10 @@ public void init(FilterConfig config) throws ServletException
                         NativeWebSocketConfiguration.class.getName() + " at ServletContext attribute '" + configurationKey + "'");
                 }
             }
-            else
-            {
-                // We have a NativeWebSocketConfiguration already present, make sure it exists on the ServletContext
-                if (config.getServletContext().getAttribute(configurationKey) == null)
-                {
-                    config.getServletContext().setAttribute(configurationKey, this.configuration);
-                }
-            }
 
             if (!this.configuration.isRunning())
             {
-                localConfiguration = true;
+                managedConfiguration = true;
                 this.configuration.start();
             }