CLJ-2898 Add additional check to prevent FI conversion if object is both IFn and FI

puredanger · puredanger · commit 97b57d6868a6 · 2025-02-25T15:00:06.000-06:00
diff --git a/src/jvm/clojure/lang/Compiler.java b/src/jvm/clojure/lang/Compiler.java
@@ -1651,7 +1651,7 @@ private static Class toInvokerParamType(Class c) {
 	 * If targetClass is FI and has an adaptable functional method
 	 *   Find fn invoker method matching adaptable method of FI
 	 *   Emit bytecode for (expr is emitted):
-	 *     if(expr instanceof IFn)
+	 *     if(expr instanceof IFn && !(expr instanceof FI))
 	 *       invokeDynamic(targetMethod, fnInvokerImplMethod)
 	 * Else emit nothing
 	 */
@@ -1686,15 +1686,18 @@ static boolean maybeEmitFIAdapter(ObjExpr objx, GeneratorAdapter gen, Expr expr,
 		try {
 			java.lang.reflect.Method fnInvokerMethod = FnInvokers.class.getMethod(invokerMethodName, invokerParams);
 
-			// if(exp instanceof IFn) { emitInvokeDynamic(targetMethod, fnInvokerMethod) }
+			// if not (expr instanceof IFn), go to end label
 			expr.emit(C.EXPRESSION, objx, gen);
 			gen.dup();
 			gen.instanceOf(ifnType);
-
-			// if not instanceof IFn, go to end
 			Label endLabel = gen.newLabel();
 			gen.ifZCmp(Opcodes.IFEQ, endLabel);
 
+			// if (expr instanceof FI), go to end label
+			gen.dup();
+			gen.instanceOf(samType);
+			gen.ifZCmp(Opcodes.IFNE, endLabel);
+
 			// else adapt fn invoker method as impl for target method
 			emitInvokeDynamicAdapter(gen, targetClass, targetMethod, FnInvokers.class, fnInvokerMethod);
 
diff --git a/test/clojure/test_clojure/java_interop.clj b/test/clojure/test_clojure/java_interop.clj
@@ -859,3 +859,15 @@
 
    (testing "Static method accepting FI arg, provided overloaded static class FI"
      (is (= \S (FunctionalTester/staticMethodWithFIArg "Static" 0 FunctionalTester/getChar)))))
+
+(deftest CLJ-2898-reified-objs-both-IFn-and-FI
+  (let [tl (ThreadLocal/withInitial
+             (reify
+               java.util.function.Supplier
+               (get [_] 100)
+
+               clojure.lang.IFn
+               (applyTo [_ _] 201)
+               (invoke [_] 200)))]
+    ;; should not be adapted and use Supplier.get() impl on tl
+    (is (= 100 (.get tl)))))
