core: fix anonymous class codegen

jadx-core/src/main/java/jadx/core/codegen/InsnGen.java

@@ -524,10 +524,10 @@ public class InsnGen {
 		if (cls != null && cls.isAnonymous()) {
 			// anonymous class construction
 			ClassInfo parent;
-			if (cls.getSuperClass() != null && !cls.getSuperClass().isObject()) {
-				parent = cls.getSuperClass();
-			} else {
+			if (cls.getInterfaces().size() == 1) {
 				parent = cls.getInterfaces().get(0);
+			} else {
+				parent = cls.getSuperClass();
 			}
 			MethodNode defCtr = cls.getDefaultConstructor();
 			if (RegionUtils.notEmpty(defCtr.getRegion())) {
@@ -535,7 +535,7 @@ public class InsnGen {
 			} else {
 				defCtr.getAttributes().add(AttributeFlag.DONT_GENERATE);
 			}
-			code.add("new ").add(useClass(parent)).add("() ");
+			code.add("new ").add(parent == null ? "Object" : useClass(parent)).add("() ");
 			code.incIndent(2);
 			new ClassGen(cls, mgen.getClassGen().getParentGen(), fallback).makeClassBody(code);
 			code.decIndent(2);

jadx-core/src/main/java/jadx/core/dex/nodes/ClassNode.java

@@ -338,15 +338,17 @@ public class ClassNode extends LineAttrNode implements ILoadable {
 	}
 
 	public boolean isAnonymous() {
-		MethodNode defConstrExists = getDefaultConstructor();
-		return defConstrExists != null && getShortName().startsWith(Consts.ANONYMOUS_CLASS_PREFIX);
+		return clsInfo.isInner()
+				&& getShortName().startsWith(Consts.ANONYMOUS_CLASS_PREFIX)
+				&& getDefaultConstructor() != null;
 	}
 
 	public MethodNode getDefaultConstructor() {
 		for (MethodNode mth : methods) {
 			if (mth.getAccessFlags().isConstructor()
 					&& mth.getMethodInfo().isConstructor()
-					&& mth.getArguments(false).isEmpty()) {
+					&& (mth.getMethodInfo().getArgsCount() == 0
+						|| (mth.getArguments(false) != null && mth.getArguments(false).isEmpty()))) {
 				return mth;
 			}
 		}

jadx-samples/src/main/java/jadx/samples/TestInner.java

@@ -63,6 +63,19 @@ public class TestInner extends AbstractTest {
 		}.run();
 	}
 
+	public String func3() {
+		return new Object() {
+			{
+				count += 7;
+			}
+			@Override
+			public String toString() {
+				count += 8;
+				return Integer.toString(count);
+			}
+		}.toString();
+	}
+
 	@SuppressWarnings("serial")
 	public static class MyException extends Exception {
 		public MyException(String str, Exception e) {
@@ -94,6 +107,8 @@ public class TestInner extends AbstractTest {
 		thread.join();
 		thread2.join();
 
-		return TestInner.count == 26;
+		assertEquals(func3(), "41");
+
+		return TestInner.count == 41;
 	}
 }