From 81dc6e267babbca337c058dacb27ab9335027cf8 Mon Sep 17 00:00:00 2001
From: JOO200 <github@joo200.de>
Date: Sun, 19 Apr 2020 00:41:22 +0200
Subject: [PATCH] Don't allow infinite recursive annotations (#258)

---
 core/src/main/java/co/aikar/commands/Annotations.java | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/core/src/main/java/co/aikar/commands/Annotations.java b/core/src/main/java/co/aikar/commands/Annotations.java
index 48ef4e33..92e840a2 100644
--- a/core/src/main/java/co/aikar/commands/Annotations.java
+++ b/core/src/main/java/co/aikar/commands/Annotations.java
@@ -27,6 +27,8 @@ import java.lang.annotation.Annotation;
 import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.IdentityHashMap;
 import java.util.Map;
 
@@ -50,7 +52,7 @@ class Annotations <M extends CommandManager> extends AnnotationLookups {
     }
 
     String getAnnotationValue(AnnotatedElement object, Class<? extends Annotation> annoClass, int options) {
-        Annotation annotation = getAnnotationRecursive(object, annoClass);
+        Annotation annotation = getAnnotationRecursive(object, annoClass, new HashSet<>());
         String value = null;
 
         if (annotation != null) {
@@ -103,13 +105,15 @@ class Annotations <M extends CommandManager> extends AnnotationLookups {
         return value;
     }
 
-    private static Annotation getAnnotationRecursive(AnnotatedElement object, Class<? extends Annotation> annoClass) {
+    private static Annotation getAnnotationRecursive(AnnotatedElement object, Class<? extends Annotation> annoClass, Collection<Annotation> checked) {
         if (object.isAnnotationPresent(annoClass)) {
             return object.getAnnotation(annoClass);
         } else {
             for (Annotation otherAnnotation : object.getDeclaredAnnotations()) {
                 if (!otherAnnotation.annotationType().getPackage().getName().startsWith("java.")) {
-                    final Annotation foundAnnotation = getAnnotationRecursive(otherAnnotation.annotationType(), annoClass);
+                    if (checked.contains(otherAnnotation)) return null;
+                    checked.add(otherAnnotation);
+                    final Annotation foundAnnotation = getAnnotationRecursive(otherAnnotation.annotationType(), annoClass, checked);
                     if (foundAnnotation != null) {
                         return foundAnnotation;
                     }