Guarded pattern with total primary pattern inside instanceof

[Tagir Valeev]

Hello!

I tried the following code:

public class Demo {
  static void test(Object obj) {
    if (obj instanceof (Object o && String.valueOf(o).equals("null"))) {
      System.out.println("null");
    }
  }

  public static void main(String[] args) {
    test(null);
    test("null");
  }
}

As (Object o && String.valueOf(o).equals("null")) is not a total
pattern, I expect this code to be compilable successfully (and it
should print "null" once). However, javac has its own opinion:

Demo.java:5: error: expression type Object is a subtype of pattern type Object
    if (obj instanceof (Object o && String.valueOf(o).equals("null"))) {
            ^

I'm using
openjdk version "17" 2021-09-14
OpenJDK Runtime Environment (build 17+35-2724)

Spec is quite unambiguous here [1], so I believe it's a javac problem.

[1] https://docs.oracle.com/javase/specs/jls/se17/preview/specs/patterns-switch-jls.html#jls-15.20.2