Trouble annotating explicit receiver with ECJ (works fine with javac)

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/ast/AbstractMethodDeclaration.java

@@ -675,6 +675,7 @@ public void resolveReceiver() {
 			this.receiver.qualifyingName = null;
 		}
 
+		resolvedReceiverType = this.scope.environment().getShallowUnannotatedType(resolvedReceiverType);
 		if (TypeBinding.notEquals(enclosingReceiver, resolvedReceiverType)) {
 			this.scope.problemReporter().illegalTypeForExplicitThis(this.receiver, enclosingReceiver);
 		}

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/lookup/LookupEnvironment.java

@@ -2451,6 +2451,19 @@ public void addResolutionListener(IQualifiedTypeResolutionListener resolutionLis
 public TypeBinding getUnannotatedType(TypeBinding typeBinding) {
 	return this.typeSystem.getUnannotatedType(typeBinding);
 }
+public TypeBinding getShallowUnannotatedType(TypeBinding typeBinding) {
+	if (typeBinding instanceof ReferenceBinding ref && ref.hasTypeAnnotations()) {
+		TypeBinding original = ref.original();
+		if (ref instanceof ParameterizedTypeBinding ptb && ptb.arguments != null && original instanceof ReferenceBinding originalRef) {
+			for (TypeBinding arg : ptb.arguments) {
+				if (arg.hasTypeAnnotations())
+					return createParameterizedType(originalRef, ptb.arguments, ptb.enclosingType);
+			}
+		}
+		return this.typeSystem.getUnannotatedType(typeBinding);
+	}
+	return typeBinding;
+}
 
 // Given a type, return all its variously annotated versions.
 public TypeBinding[] getAnnotatedTypes(TypeBinding type) {

org.eclipse.jdt.core.tests.compiler/src/org/eclipse/jdt/core/tests/compiler/regression/NullTypeAnnotationTest.java

@@ -19812,4 +19812,27 @@ void expire() {}
 			""";
 	runner.runNegativeTest();
 }
+
+public void testGH4494() throws Exception {
+	runConformTest(new String[] {
+			"AnnotatedExplicitReceiverError.java",
+			"""
+			import java.lang.annotation.ElementType;
+			import java.lang.annotation.Target;
+
+			public class AnnotatedExplicitReceiverError {
+			    @Target({ ElementType.TYPE_USE})
+			    private static @interface A { }
+
+			    @Target({ ElementType.TYPE_USE, ElementType.TYPE_PARAMETER })
+			    private static @interface F { }
+
+			    static class P<@A T> {
+			        public void explicitReceiver(@F P<T> this) { // error here
+			        }
+			    }
+			}
+			"""
+	});
+}
 }