From e21db2619bd95991548d15147144b94bca7a4cad Mon Sep 17 00:00:00 2001
From: Juergen Hoeller <jhoeller@pivotal.io>
Date: Sun, 22 Jul 2018 22:28:48 +0200
Subject: [PATCH] AspectJExpressionPointcut leniently ignores non-composable
 interfaces

Issue: SPR-17003

(cherry picked from commit bccff73)
---
 .../aspectj/AspectJExpressionPointcut.java    | 39 +++++++++++--------
 .../org/springframework/util/ClassUtils.java  |  2 +
 2 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java b/spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java
index 5f3a68e4ca..8a2b25d539 100644
--- a/spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java
+++ b/spring-aop/src/main/java/org/springframework/aop/aspectj/AspectJExpressionPointcut.java
@@ -434,9 +434,15 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 			// Note: AspectJ is only going to take Method.getDeclaringClass() into account.
 			Set<Class<?>> ifcs = ClassUtils.getAllInterfacesForClassAsSet(targetClass);
 			if (ifcs.size() > 1) {
-				Class<?> compositeInterface = ClassUtils.createCompositeInterface(
-						ClassUtils.toClassArray(ifcs), targetClass.getClassLoader());
-				targetMethod = ClassUtils.getMostSpecificMethod(targetMethod, compositeInterface);
+				try {
+					Class<?> compositeInterface = ClassUtils.createCompositeInterface(
+							ClassUtils.toClassArray(ifcs), targetClass.getClassLoader());
+					targetMethod = ClassUtils.getMostSpecificMethod(targetMethod, compositeInterface);
+				}
+				catch (IllegalArgumentException ex) {
+					// Implemented interfaces probably expose conflicting method signatures...
+					// Proceed with original target method.
+				}
 			}
 		}
 		return getShadowMatch(targetMethod, method);
@@ -561,6 +567,19 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 		return sb.toString();
 	}
 
+	//---------------------------------------------------------------------
+	// Serialization support
+	//---------------------------------------------------------------------
+
+	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
+		// Rely on default serialization, just initialize state after deserialization.
+		ois.defaultReadObject();
+
+		// Initialize transient fields.
+		// pointcutExpression will be initialized lazily by checkReadyToMatch()
+		this.shadowMatchCache = new ConcurrentHashMap<>(32);
+	}
+
 
 	/**
 	 * Handler for the Spring-specific {@code bean()} pointcut designator
@@ -657,20 +676,6 @@ public class AspectJExpressionPointcut extends AbstractExpressionPointcut
 	}
 
 
-	//---------------------------------------------------------------------
-	// Serialization support
-	//---------------------------------------------------------------------
-
-	private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
-		// Rely on default serialization, just initialize state after deserialization.
-		ois.defaultReadObject();
-
-		// Initialize transient fields.
-		// pointcutExpression will be initialized lazily by checkReadyToMatch()
-		this.shadowMatchCache = new ConcurrentHashMap<>(32);
-	}
-
-
 	private static class DefensiveShadowMatch implements ShadowMatch {
 
 		private final ShadowMatch primary;
diff --git a/spring-core/src/main/java/org/springframework/util/ClassUtils.java b/spring-core/src/main/java/org/springframework/util/ClassUtils.java
index f274ef24fb..59663421bc 100644
--- a/spring-core/src/main/java/org/springframework/util/ClassUtils.java
+++ b/spring-core/src/main/java/org/springframework/util/ClassUtils.java
@@ -754,6 +754,8 @@ public abstract class ClassUtils {
 	 * @param interfaces the interfaces to merge
 	 * @param classLoader the ClassLoader to create the composite Class in
 	 * @return the merged interface as Class
+	 * @throws IllegalArgumentException if the specified interfaces expose
+	 * conflicting method signatures (or a similar constraint is violated)
 	 * @see java.lang.reflect.Proxy#getProxyClass
 	 */
 	@SuppressWarnings("deprecation")