fix: always cast null objects in overloaded method (#707)

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

@@ -807,11 +807,22 @@ public class InsnGen {
 				return false;
 			}
 		}
+		if (isCastNeeded(arg, origType)) {
+			code.add('(');
+			useType(code, origType);
+			code.add(") ");
+			return true;
+		}
+		return false;
+	}
+
+	private boolean isCastNeeded(InsnArg arg, ArgType origType) {
 		ArgType argType = arg.getType();
-		if (argType.equals(origType)
-				// null cast to object
-				&& (!arg.isLiteral() || ((LiteralArg) arg).getLiteral() != 0
-						|| (!argType.isArray() && !argType.isObject()))) {
+		if (arg.isLiteral() && ((LiteralArg) arg).getLiteral() == 0
+				&& (argType.isObject() || argType.isArray())) {
+			return true;
+		}
+		if (argType.equals(origType)) {
 			return false;
 		}
 		if (origType.isGeneric()) {
@@ -828,9 +839,6 @@ public class InsnGen {
 				((InsnWrapArg) arg).getWrapInsn().add(AFlag.EXPLICIT_GENERICS);
 			}
 		}
-		code.add('(');
-		useType(code, origType);
-		code.add(") ");
 		return true;
 	}
 

jadx-core/src/test/java/jadx/tests/integration/others/TestCastOfNull.java

@@ -1,5 +1,7 @@
 package jadx.tests.integration.others;
 
+import java.util.List;
+
 import org.junit.jupiter.api.Test;
 
 import jadx.core.dex.nodes.ClassNode;
@@ -15,6 +17,7 @@ public class TestCastOfNull extends IntegrationTest {
 		public void test() {
 			m((long[]) null);
 			m((String) null);
+			m((List<String>) null);
 		}
 
 		public void m(long[] a) {
@@ -22,6 +25,9 @@ public class TestCastOfNull extends IntegrationTest {
 
 		public void m(String s) {
 		}
+
+		public void m(List<String> list) {
+		}
 	}
 
 	@Test
@@ -31,5 +37,6 @@ public class TestCastOfNull extends IntegrationTest {
 
 		assertThat(code, containsOne("m((long[]) null);"));
 		assertThat(code, containsOne("m((String) null);"));
+		assertThat(code, containsOne("m((List<String>) null);"));
 	}
 }