From ec03fd022f032abc1669d0ff485c60db5ad1b5c3 Mon Sep 17 00:00:00 2001
From: Decebal Suiu <decebal.suiu@gmail.com>
Date: Tue, 21 Apr 2020 15:30:35 +0300
Subject: [PATCH] Fix #363

---
 .../org/pf4j/AbstractExtensionFinder.java     |  8 ++++---
 .../org/pf4j/AbstractExtensionFinderTest.java | 17 +++++++++++++++
 .../ExtensionAnnotationProcessorTest.java     | 21 +++++++++++++++++++
 3 files changed, 43 insertions(+), 3 deletions(-)

diff --git a/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java b/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java
index e2bd327..a156fab 100644
--- a/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java
+++ b/pf4j/src/main/java/org/pf4j/AbstractExtensionFinder.java
@@ -356,9 +356,11 @@ public abstract class AbstractExtensionFinder implements ExtensionFinder, Plugin
         // search recursively through all annotations
         for (Annotation annotation : clazz.getAnnotations()) {
             Class<? extends Annotation> annotationClass = annotation.annotationType();
-            Extension extensionAnnotation = findExtensionAnnotation(annotationClass);
-            if (extensionAnnotation != null) {
-                return extensionAnnotation;
+            if (!annotationClass.getName().startsWith("java.lang.annotation")) {
+                Extension extensionAnnotation = findExtensionAnnotation(annotationClass);
+                if (extensionAnnotation != null) {
+                    return extensionAnnotation;
+                }
             }
         }
 
diff --git a/pf4j/src/test/java/org/pf4j/AbstractExtensionFinderTest.java b/pf4j/src/test/java/org/pf4j/AbstractExtensionFinderTest.java
index 74ccadb..bcf1535 100644
--- a/pf4j/src/test/java/org/pf4j/AbstractExtensionFinderTest.java
+++ b/pf4j/src/test/java/org/pf4j/AbstractExtensionFinderTest.java
@@ -37,6 +37,7 @@ import java.util.Set;
 
 import static com.google.testing.compile.CompilationSubject.assertThat;
 import static com.google.testing.compile.Compiler.javac;
+import static org.junit.Assert.assertNull;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.mockito.Mockito.eq;
@@ -217,6 +218,22 @@ public class AbstractExtensionFinderTest {
         assertNotNull(extension);
     }
 
+    @Test
+    public void findExtensionAnnotationThatMissing() throws Exception {
+        Compilation compilation = javac().compile(ExtensionAnnotationProcessorTest.Greeting,
+            ExtensionAnnotationProcessorTest.SpinnakerExtension_NoExtension,
+            ExtensionAnnotationProcessorTest.WhazzupGreeting_SpinnakerExtension);
+        assertThat(compilation).succeededWithoutWarnings();
+        ImmutableList<JavaFileObject> generatedFiles = compilation.generatedFiles();
+        assertEquals(3, generatedFiles.size());
+
+        JavaFileObjectClassLoader classLoader = new JavaFileObjectClassLoader();
+        Map<String, Class<?>> loadedClasses = classLoader.loadClasses(new ArrayList<>(generatedFiles));
+        Class<?> clazz = loadedClasses.get("test.WhazzupGreeting");
+        Extension extension = AbstractExtensionFinder.findExtensionAnnotation(clazz);
+        assertNull(extension);
+    }
+
    static class JavaFileObjectClassLoader extends ClassLoader {
 
         public Map<String, Class<?>> loadClasses(List<JavaFileObject> classes) throws IOException {
diff --git a/pf4j/src/test/java/org/pf4j/ExtensionAnnotationProcessorTest.java b/pf4j/src/test/java/org/pf4j/ExtensionAnnotationProcessorTest.java
index 652c754..f966523 100644
--- a/pf4j/src/test/java/org/pf4j/ExtensionAnnotationProcessorTest.java
+++ b/pf4j/src/test/java/org/pf4j/ExtensionAnnotationProcessorTest.java
@@ -103,6 +103,27 @@ public class ExtensionAnnotationProcessorTest {
         "    }",
         "}");
 
+    /**
+     * The same like {@link #SpinnakerExtension} but without {@code Extension} annotation.
+     */
+    public static final JavaFileObject SpinnakerExtension_NoExtension = JavaFileObjects.forSourceLines(
+        "SpinnakerExtension",
+        "package test;",
+        "",
+        "import org.pf4j.Extension;",
+        "import java.lang.annotation.Documented;",
+        "import java.lang.annotation.ElementType;",
+        "import java.lang.annotation.Retention;",
+        "import java.lang.annotation.RetentionPolicy;",
+        "import java.lang.annotation.Target;",
+        "",
+//        "@Extension",
+        "@Retention(RetentionPolicy.RUNTIME)",
+        "@Target(ElementType.TYPE)",
+        "@Documented",
+        "public @interface SpinnakerExtension {",
+        "}");
+
     @Test
     public void getSupportedAnnotationTypes() {
         ExtensionAnnotationProcessor instance = new ExtensionAnnotationProcessor();
-- 
2.39.5