#589 Lambda and nested interface - cannot obfuscate

[Adam Bartoszewicz]

Hello,
I use Proguard v. 5.2.1, jdk 1.8.45 Windows 10 and Eclipse IDE.

Proguard fails when obfuscating lambda expression containing anonymous class.
There is simple workaround: change anonymous class to lamda

My 4 simple files:
/////NestedInterfaceTest.java

package proguard;

public class NestedInterfaceTest {
    private IPrint1 iPrint;

    public NestedInterfaceTest(IPrint1 iPrint) {
        this.iPrint = iPrint;
    }

    public static void main(String[] args) {
        NestedInterfaceTest nestedInterfaceTest = new NestedInterfaceTest(()->{
            DataToPrint dataToPrint = new DataToPrint();
            dataToPrint.setIPrint2(new IPrint2() {
                @Override
                public String convert(String s) {
                    return s.toUpperCase();
                }
            });

            //
            // this works:
            //dataToPrint.setIPrint2(s->s.toUpperCase());
            //
            dataToPrint.setValue("aaaaaaaa");
            System.out.println(dataToPrint.getValue());
        });
        nestedInterfaceTest.iPrint.printValue();
    }
}

////DataToPrint.java

package proguard;

public class DataToPrint {
    private String value;
    private IPrint2 iPrint2;

    public void setValue(String value) {
        this.value = iPrint2.convert(value);
    }

    public void setIPrint2(IPrint2 iPrint2) {
        this.iPrint2 = iPrint2;
    }

    public String getValue() {
        return value;
    }
}

////IPrint1.java

package proguard;
public interface IPrint1 {
    public void printValue();
}

////IPrint2.java

package proguard;
public interface IPrint2 {
    public String convert(String s);
}

Proguard output:

ProGuard, version 5.2.1
Reading program jar [C:\gxdevel\gx\proguard_test\nestedinterfacetest.jar]
Reading library jar [C:\Program Files\Java\jdk1.8.0_45\jre\lib\rt.jar]
Warning: proguard.NestedInterfaceTest$1: can't find enclosing method 'void lambda$1()' in program class proguard.NestedInterfaceTest
Warning: there were 1 unresolved references to program class members.
         Your input classes appear to be inconsistent.
         You may need to recompile the code.
         (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedprogramclassmember)
Error: Please correct the above warnings first.

Thanks
Adam

[Renwei Liou]

This problem still happens in the latest release 5.3.2. I can reproduce it with a simple example:
Stream.of(1).map(i -> new Object() {}).forEach(o -> System.out.println(o));

which generates the error
Warning: <class name="">: can't find enclosing method 'java.lang.Object lambda$28(java.lang.Integer)' in program class ...</class>

This is common usage and should not cause any errors.
Thanks.