Incorrect template type inferred from closure

[muglug]

Bug report

In the code below the type T should not be inferred from the callable param, but from the first arg. Callable params act as an upper bound on the possible type.

Code snippet that reproduces the problem

class C {
	public function foo() : void {}
}

/**
 * @psalm-template T
 * @psalm-param T $t
 * @psalm-param callable(?T):void $callable
 * @return T
 */
function makeConcrete($t, callable $callable) {
	$callable(rand(0, 1) ? $t : null);
	return $t;
}

$c = makeConcrete(new C(), function (?C $c) : void {});
$c->foo();

https://phpstan.org/r/a30bb64f-9723-460b-8d09-33efb3afdc40

Expected output

No issue

Actual output

Cannot call method foo() on C|null

[phpstan-bot]

@muglug After the latest commit in dev-master, PHPStan now reports different result with your code snippet:

@@ @@
-18: Cannot call method foo() on C|null.
+No errors

[ondrejmirtes]

Fixed: phpstan/phpstan-src@a1b7b38

[github-actions]

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