GROOVY-11467: SC: super interface method reference from an abstract type

Author: eric-milles

src/main/java/org/codehaus/groovy/classgen/asm/sc/StaticTypesMethodReferenceExpressionWriter.java

@@ -45,6 +45,7 @@
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 import static java.util.Comparator.comparingInt;
 import static java.util.stream.Collectors.joining;
@@ -308,10 +309,14 @@ private MethodNode chooseMethodRefMethod(final List<MethodNode> methods, final E
 
     private List<MethodNode> findVisibleMethods(final String name, final ClassNode type) {
         List<MethodNode> methods = type.getMethods(name);
-        // GROOVY-10791: include interface default methods in search
-        for (ClassNode cn : getInterfacesAndSuperInterfaces(type)) {
+        // GROOVY-10791, GROOVY-11467: include non-static interface methods
+        Set<ClassNode> implemented = getInterfacesAndSuperInterfaces(type);
+        implemented.remove(type);
+        for (ClassNode cn : implemented) {
             for (MethodNode mn : cn.getDeclaredMethods(name)) {
-                if (mn.isDefault()) methods.add(mn);
+                if (mn.isDefault() || (mn.isPublic() && !mn.isStatic() && type.isAbstract())) {
+                    methods.add(mn);
+                }
             }
         }
         methods.addAll(findDGMMethodsForClassNode(controller.getSourceUnit().getClassLoader(), type, name));

src/test/groovy/transform/stc/MethodReferenceTest.groovy

@@ -1531,4 +1531,24 @@ final class MethodReferenceTest {
             assert result == 'something'
         '''
     }
+
+    @Test // GROOVY-11467
+    void testSuperInterfaceMethodReference() {
+        assertScript imports + '''
+            interface A { int m() }
+            interface B extends A { }
+            class C implements B { int m() { 42 } }
+
+            @CompileStatic
+            class D {
+                B b = new C()
+                void test() {
+                    IntSupplier s = b::m
+                    assert s.getAsInt() == 42
+                }
+            }
+
+            new D().test()
+        '''
+    }
 }