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The following commit(s) were added to refs/heads/master by this push:
new 245d8dffc EqualsBuilder.reflectionEquals() array branch missing cycle
guard causes (#1653)
245d8dffc is described below
commit 245d8dffcdab9ba3286b6493da595e28094d42a9
Author: Gary Gregory <[email protected]>
AuthorDate: Sun May 17 17:07:22 2026 -0400
EqualsBuilder.reflectionEquals() array branch missing cycle guard causes
(#1653)
StackOverflow on self-referential Object arrays
---
.../commons/lang3/builder/EqualsBuilder.java | 38 ++++++++------
.../EqualsBuilderReflectionEqualsCycleTest.java | 61 ++++++++++++++++++++++
2 files changed, 82 insertions(+), 17 deletions(-)
diff --git a/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java
b/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java
index 1bb5ed61d..c478ff335 100644
--- a/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java
+++ b/src/main/java/org/apache/commons/lang3/builder/EqualsBuilder.java
@@ -26,7 +26,6 @@
import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.ClassUtils;
-import org.apache.commons.lang3.builder.AbstractReflection.AbstractBuilder;
import org.apache.commons.lang3.tuple.Pair;
/**
@@ -171,7 +170,7 @@ static Set<Pair<IDKey, IDKey>> getRegistry() {
* <p>
* Used by the reflection methods to avoid infinite loops.
* Objects might be swapped therefore a check is needed if the object pair
- * is registered in given or swapped order.
+ * is registered in the given or swapped order.
* </p>
*
* @param lhs {@code this} object to lookup in registry
@@ -409,7 +408,7 @@ public EqualsBuilder() {
bypassReflectionClasses.add(String.class); //hashCode field being lazy
but not transient
}
- private EqualsBuilder(Builder builder) {
+ private EqualsBuilder(final Builder builder) {
super(builder);
}
@@ -793,24 +792,29 @@ public EqualsBuilder append(final Object lhs, final
Object rhs) {
* @return {@code this} instance.
*/
public EqualsBuilder append(final Object[] lhs, final Object[] rhs) {
- if (!isEquals) {
- return this;
- }
- if (lhs == rhs) {
+ if (!isEquals || isRegistered(lhs, rhs)) {
return this;
}
- if (lhs == null || rhs == null) {
- setEquals(false);
- return this;
- }
- if (lhs.length != rhs.length) {
- setEquals(false);
+ try {
+ register(lhs, rhs);
+ if (lhs == rhs) {
+ return this;
+ }
+ if (lhs == null || rhs == null) {
+ setEquals(false);
+ return this;
+ }
+ if (lhs.length != rhs.length) {
+ setEquals(false);
+ return this;
+ }
+ for (int i = 0; i < lhs.length && isEquals; ++i) {
+ append(lhs[i], rhs[i]);
+ }
return this;
+ } finally {
+ unregister(lhs, rhs);
}
- for (int i = 0; i < lhs.length && isEquals; ++i) {
- append(lhs[i], rhs[i]);
- }
- return this;
}
/**
diff --git
a/src/test/java/org/apache/commons/lang3/builder/EqualsBuilderReflectionEqualsCycleTest.java
b/src/test/java/org/apache/commons/lang3/builder/EqualsBuilderReflectionEqualsCycleTest.java
new file mode 100644
index 000000000..d0192c4e4
--- /dev/null
+++
b/src/test/java/org/apache/commons/lang3/builder/EqualsBuilderReflectionEqualsCycleTest.java
@@ -0,0 +1,61 @@
+/*
+ * 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.builder;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests {@link EqualsBuilder#reflectionEquals(Object, Object, String...)}.
+ * <p>
+ * reflectionEquals array fix enables cyclic-array.
+ * </p>
+ * <p>
+ * Pre-patch: Object[] elements containing themselves cause StackOverflowError
when compared via EqualsBuilder.reflectionEquals because the array branch in
+ * reflectionAppend calls append(lhs, rhs) which recurses without cycle check.
+ * </p>
+ * <p>
+ * Post-patch: the arrays are registered before recursing so cycles are
detected and the comparison terminates (returning false).
+ * </p>
+ */
+class EqualsBuilderReflectionEqualsCycleTest {
+
+ @Test
+ void testSelfReferentialObjectArrays() {
+ final Object[] a = new Object[1];
+ final Object[] b = new Object[1];
+ a[0] = a;
+ b[0] = b;
+ // Pre-patch: StackOverflowError; Post-patch: terminates without error.
+ // With cycle detection, comparing a[0]=a vs b[0]=b sees (a,b) already
registered
+ // and treats the cycle as equal, so the overall result is true
(structurally isomorphic).
+ // The key assertion is that NO StackOverflowError is thrown.
+ assertTrue(EqualsBuilder.reflectionEquals(a, b));
+ }
+
+ @Test
+ void testCrossReferentialObjectArrays() {
+ final Object[] a = new Object[1];
+ final Object[] b = new Object[1];
+ // a[0] -> b, b[0] -> a: mutual cycle
+ a[0] = b;
+ b[0] = a;
+ assertTrue(EqualsBuilder.reflectionEquals(a, b));
+ }
+}
