Return type T does not accept T&null

[jlherren]

Bug report

After upgrading to PHPStan 1.0, I find that a function that should return T does not accept returning T&null, where T is a template type.

Code snippet that reproduces the problem

/**
 * @template T
 * @param T $t
 * @return T
 */
function test($t) {
	if ($t === null) {
		return $t; // <-- Error: Function test() should return T but returns T&null.
	}
	return $t;
}

https://phpstan.org/r/984459d4-1124-4ca9-888c-dc3d31b979fb

Expected output

No error

Did PHPStan help you today? Did it make you happy in any way?

I'm all excited about the 1.0 release :)

[voku]

Looks like a doublicate issue, or?: #5591

[ondrejmirtes]

/cc @arnaud-lb Also this one :)

[phpstan-bot]

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

@@ @@
-9: Function test() should return T but returns T&null.
+No errors

[ondrejmirtes]

Fixed: phpstan/phpstan-src@9f12f0f

[github-actions]

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