From e6c4855a930f670fc3db633443a8a61b8dc06db4 Mon Sep 17 00:00:00 2001
From: Liam Miller-Cushon <cushon@google.com>
Date: Mon, 19 Jan 2026 10:49:44 +0100
Subject: [PATCH] Only resolve object methods on interfaces

---
 .../sun/tools/javac/comp/LambdaToMethod.java   | 14 ++++++++------
 ...ableObjectMethodReferencesOnInterfaces.java | 18 ++++++++++++++++++
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java
index f9af7d7b803..3c9ec8ff938 100644
--- a/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java
+++ b/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/LambdaToMethod.java
@@ -702,12 +702,14 @@ public class LambdaToMethod extends TreeTranslator {
         String functionalInterfaceClass = classSig(targetType);
         String functionalInterfaceMethodName = samSym.getSimpleName().toString();
         String functionalInterfaceMethodSignature = typeSig(types.erasure(samSym.type));
-        Symbol baseMethod = types.overriddenObjectMethod(refSym.enclClass(), refSym);
-        if (baseMethod != null) {
-            // The implementation method is a java.lang.Object method, runtime will resolve this method to
-            // a java.lang.Object method, so do the same.
-            // This case can be removed if JDK-8172817 is fixed.
-            refSym = ((MethodSymbol) baseMethod).asHandle();
+        if (refSym.enclClass().isInterface()) {
+            Symbol baseMethod = types.overriddenObjectMethod(refSym.enclClass(), refSym);
+            if (baseMethod != null) {
+                // The implementation method is a java.lang.Object method, runtime will resolve this method to
+                // a java.lang.Object method, so do the same.
+                // This case can be removed if JDK-8172817 is fixed.
+                refSym = ((MethodSymbol) baseMethod).asHandle();
+            }
         }
         String implClass = classSig(types.erasure(refSym.owner.type));
         String implMethodName = refSym.getQualifiedName().toString();
diff --git a/test/langtools/tools/javac/lambda/SerializableObjectMethodReferencesOnInterfaces.java b/test/langtools/tools/javac/lambda/SerializableObjectMethodReferencesOnInterfaces.java
index 27fb3ac9aa5..dfe4d64d1e3 100644
--- a/test/langtools/tools/javac/lambda/SerializableObjectMethodReferencesOnInterfaces.java
+++ b/test/langtools/tools/javac/lambda/SerializableObjectMethodReferencesOnInterfaces.java
@@ -63,9 +63,15 @@ public class SerializableObjectMethodReferencesOnInterfaces {
             R apply(T t);
         }
 
+        enum E {
+            ONE
+        }
+
         void f() throws Exception {
             F<I1, Integer> f1 = I1::hashCode;
             F<I2, Integer> f2 = I2::hashCode;
+            F<E, Integer> f3 = E::hashCode;
+            F<Object, Integer> f4 = Object::hashCode;
         }
     }
 
@@ -91,6 +97,18 @@ public class SerializableObjectMethodReferencesOnInterfaces {
                 getFunctionalInterfaceMethodSignature (Ljava/lang/Object;)Ljava/lang/Object;
                 getImplClass java/lang/Object
                 getImplMethodSignature ()I
+                getImplMethodKind 5
+                getFunctionalInterfaceClass SerializableObjectMethodReferencesOnInterfaces$Test$F
+                getFunctionalInterfaceMethodName apply
+                getFunctionalInterfaceMethodSignature (Ljava/lang/Object;)Ljava/lang/Object;
+                getImplClass java/lang/Enum
+                getImplMethodSignature ()I
+                getImplMethodKind 5
+                getFunctionalInterfaceClass SerializableObjectMethodReferencesOnInterfaces$Test$F
+                getFunctionalInterfaceMethodName apply
+                getFunctionalInterfaceMethodSignature (Ljava/lang/Object;)Ljava/lang/Object;
+                getImplClass java/lang/Object
+                getImplMethodSignature ()I
                 """;
         if (!actual.equals(expected)) {
             throw new AssertionError(