From e9c996a17ebf05ec2bde8f2516c8eaa608268c85 Mon Sep 17 00:00:00 2001
From: Kusal Kithul-Godage <git@kusal.io>
Date: Mon, 13 Nov 2023 23:58:41 +1100
Subject: [PATCH] WW-5363 Velocity: read chained contexts before ValueStack

---
 .../views/velocity/StrutsVelocityContext.java | 49 +++++++++++++------
 1 file changed, 33 insertions(+), 16 deletions(-)

diff --git a/plugins/velocity/src/main/java/org/apache/struts2/views/velocity/StrutsVelocityContext.java b/plugins/velocity/src/main/java/org/apache/struts2/views/velocity/StrutsVelocityContext.java
index cca2b5dc31..96c213252b 100644
--- a/plugins/velocity/src/main/java/org/apache/struts2/views/velocity/StrutsVelocityContext.java
+++ b/plugins/velocity/src/main/java/org/apache/struts2/views/velocity/StrutsVelocityContext.java
@@ -24,6 +24,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.function.Function;
 
 public class StrutsVelocityContext extends VelocityContext {
 
@@ -54,7 +55,7 @@ public StrutsVelocityContext(ValueStack stack) {
     /**
      * @deprecated please use {@link #StrutsVelocityContext(List, ValueStack)}
      */
-    @Deprecated()
+    @Deprecated
     public StrutsVelocityContext(VelocityContext[] chainedContexts, ValueStack stack) {
         this(new ArrayList<>(Arrays.asList(chainedContexts)), stack);
     }
@@ -64,28 +65,44 @@ public boolean internalContainsKey(String key) {
     }
 
     public Object internalGet(String key) {
-        Object val = super.internalGet(key);
-        if (val != null) {
-            return val;
-        }
-        if (stack != null) {
-            val = stack.findValue(key);
+        return chainedGets(key, super::internalGet, this::chainedContextGet, this::stackGet, this::stackContextGet);
+    }
+
+    @SafeVarargs
+    protected static Object chainedGets(String key, Function<String, Object> ...contextGets) {
+        for (Function<String, Object> contextGet : contextGets) {
+            Object val = contextGet.apply(key);
             if (val != null) {
                 return val;
             }
-            val = stack.getContext().get(key);
+        }
+        return null;
+    }
+
+    protected Object stackGet(String key) {
+        if (stack == null) {
+            return null;
+        }
+        return stack.findValue(key);
+    }
+
+    protected Object stackContextGet(String key) {
+        if (stack == null) {
+            return null;
+        }
+        return stack.getContext().get(key);
+    }
+
+    protected Object chainedContextGet(String key) {
+        if (chainedContexts == null) {
+            return null;
+        }
+        for (VelocityContext chainedContext : chainedContexts) {
+            Object val = chainedContext.internalGet(key);
             if (val != null) {
                 return val;
             }
         }
-        if (chainedContexts != null) {
-            for (VelocityContext chainedContext : chainedContexts) {
-                val = chainedContext.internalGet(key);
-                if (val != null) {
-                    return val;
-                }
-            }
-        }
         return null;
     }
 }