Magic instance property is not defined

[rarila]

The following code gets no errors up to v5.25.
(The Psalm version on psalm.dev is at time of writing quite old, May 5th, so no problems there)

https://psalm.dev/r/6e53e9fc0c

Starting with v5.26 you get the error Magic instance property FooValue::$foo is not defined on line 56.

I tracked that down to pull request #11081.
Reversing commit 3cf1942 makes things work again, so the problem seems to be there.

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/6e53e9fc0c

<?php

declare(strict_types=1);

abstract class AbstractValue
{
    public function __get(string $name): mixed
    {
        return 123;
    }
    
    public function __set(string $name, mixed $value): void
    {
    }
}

/** @property int $foo */
final class FooValue extends AbstractValue
{
}

/** @template T of AbstractValue */
abstract class AbstractClass
{
    /** @var T */
    private AbstractValue $value;

    /** @param T $value */
    public function __construct(AbstractValue $value)
    {
        $this->value = $value;
    }

    /** @return T */
    protected function getValue(): AbstractValue
    {
        return $this->value;
    }
}

/** @extends AbstractClass<FooValue> */
final class Test extends AbstractClass
{
    public function __construct()
    {
        parent::__construct(new FooValue());

        // Works:
        echo $this->getValue()->foo;

        // Works:
        $v = $this->getValue();
        $v->foo = 1;

        // Fails with: Magic instance property FooValue::$foo is not defined
        $this->getValue()->foo = 1;
    }
}

Psalm output (using commit 16b24bd):

No issues!