fix LANG-1815

Author: inponomarev

src/main/java/org/apache/commons/lang3/AnnotationUtils.java

@@ -212,6 +212,7 @@ public static boolean equals(final Annotation a1, final Annotation a2) {
             for (final Method m : type1.getDeclaredMethods()) {
                 if (m.getParameterTypes().length == 0
                         && isValidAnnotationMemberType(m.getReturnType())) {
+                    m.setAccessible(true);
                     final Object v1 = m.invoke(a1);
                     final Object v2 = m.invoke(a2);
                     if (!memberEquals(m.getReturnType(), v1, v2)) {
@@ -220,7 +221,7 @@ && isValidAnnotationMemberType(m.getReturnType())) {
                 }
             }
         } catch (final ReflectiveOperationException ex) {
-            return false;
+            throw new IllegalStateException(ex);
         }
         return true;
     }

src/test/java/org/apache/commons/lang3/external/AnnotationEqualsTest.java

@@ -0,0 +1,46 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.lang3.external;
+
+import org.apache.commons.lang3.AnnotationUtils;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+// CAUTION: in order to reproduce https://issues.apache.org/jira/browse/LANG-1815,
+// this test MUST be located OUTSIDE org.apache.commons.lang3 package.
+// Do NOT move it to the org.apache.commons.lang3 package!
+public class AnnotationEqualsTest {
+    @Retention(RetentionPolicy.RUNTIME)
+    @interface Tag {
+        String value();
+    }
+
+    @Tag("value")
+    private final Object a = new Object();
+    @Tag("value")
+    private final Object b = new Object();
+
+    @Test
+    void equalsWorksOnPackagePrivateAnnotations() throws Exception {
+        Tag tagA = getClass().getDeclaredField("a").getAnnotation(Tag.class);
+        Tag tagB = getClass().getDeclaredField("b").getAnnotation(Tag.class);
+        Assertions.assertTrue(AnnotationUtils.equals(tagA, tagB));
+    }
+}