From 4574cb251c01495a06cfafcef585c4909a8e8623 Mon Sep 17 00:00:00 2001
From: Andreas Dangel <andreas.dangel@pmd-code.org>
Date: Sun, 5 Nov 2023 21:42:29 +0100
Subject: [PATCH] [apex] Fix AvoidNonExistentAnnotationsRule for enum values

---
 .../errorprone/AvoidNonExistentAnnotationsRule.java    |  3 +++
 .../errorprone/xml/AvoidNonExistentAnnotations.xml     | 10 ++++++++++
 2 files changed, 13 insertions(+)

diff --git a/pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/errorprone/AvoidNonExistentAnnotationsRule.java b/pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/errorprone/AvoidNonExistentAnnotationsRule.java
index d90c5d0a38..4d34bec452 100644
--- a/pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/errorprone/AvoidNonExistentAnnotationsRule.java
+++ b/pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/errorprone/AvoidNonExistentAnnotationsRule.java
@@ -59,6 +59,9 @@ public class AvoidNonExistentAnnotationsRule extends AbstractApexRule {
     }
 
     private Object checkForNonExistentAnnotation(final ApexNode<?> node, final ASTModifierNode modifierNode, final Object data) {
+        if (modifierNode == null) {
+            return data;
+        }
         for (ASTAnnotation annotation : modifierNode.findChildrenOfType(ASTAnnotation.class)) {
             if (!annotation.isResolved()) {
                 addViolationWithMessage(data, node, "Use of non existent annotations will lead to broken Apex code which will not compile in the future.");
diff --git a/pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/errorprone/xml/AvoidNonExistentAnnotations.xml b/pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/errorprone/xml/AvoidNonExistentAnnotations.xml
index e5793809e9..1b57d75dc6 100644
--- a/pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/errorprone/xml/AvoidNonExistentAnnotations.xml
+++ b/pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/errorprone/xml/AvoidNonExistentAnnotations.xml
@@ -80,4 +80,14 @@ public class Foo {
 }
         ]]></code>
     </test-code>
+
+    <test-code>
+        <description>NPE for enum values (#4722)</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class MyClass {
+    public enum MyEnum { A, B }
+}
+]]></code>
+    </test-code>
 </test-data>