Invalid type detect after AND condition

[vjik]

https://psalm.dev/r/d946add113

In this case RedundantCondition is invalid.

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/d946add113

<?php

class Obj {
    public function __construct(
    	private int $value,
    ) {}    
    public function isEqual(Obj $b): bool
    {
        return $this->value === $b->value;
    }
}

function isEqual(?Obj $a, ?Obj $b): bool
{
    if ($a === null && $b === null) {
        return true;
    }
    
    /** @psalm-trace $a, $b */
    
    if (
        ($a === null && $b !== null)
        || ($a !== null && $b === null)
    ) {
        return false;
    }

    return $a->isEqual($b);
}

Psalm output (using commit 16b24bd):

ERROR: RedundantCondition - 22:25 - Obj can never contain null

ERROR: RedundantCondition - 23:13 - Obj can never contain null

INFO: Trace - 21:5 - $a: Obj

INFO: Trace - 21:5 - $b: Obj