In jshell-11, why does a redeclared reference variable that resets to null still have a type?

Question

When redeclaring Integer \'a\' in line 33, why does jshell show the reference variable as an instance of Integer (refer to lines 38 & 39)? After the redeclaration, line 34 s

Answer 1

I've raised it as a bug and it's been accepted.

https://bugs.openjdk.java.net/browse/JDK-8211694

Good spot.

Answer 2

The problem is that, though it says it is set to null, it actually isn't. See added comments in bug for more detail.

I've changed the bug title to: JShell: Redeclared variable should be reset

I'll attempt to fix in JDK 12.

The second issue is not a bug, Java does not allow instanceof operators that cannot be true -- behavior matches javac exactly.