Mixed type of return value for a static variable that is assigned a specific type

[cazak]

This works for a typical variable: https://psalm.dev/r/8c1cff78af

But it doesn't work for a static variable: https://psalm.dev/r/32db7cf425

[psalm-github-bot[bot]]

I found these snippets:

https://psalm.dev/r/8c1cff78af

<?php

final class A
{
	public function getB(): B
    {
    	$b = null;
        
        if ($b === null) {
        	$b = new B();
        }
        
        return $b;
    }
}

final class B
{
}

Psalm output (using commit 73ebe22):

No issues!

https://psalm.dev/r/32db7cf425

<?php

final class A
{
	public function getB(): B
    {
    	static $b = null;
        
        if ($b === null) {
        	$b = new B();
        }
        
        return $b;
    }
}

final class B
{
}

Psalm output (using commit 73ebe22):

INFO: MixedReturnStatement - 13:16 - Possibly-mixed return value

INFO: MixedReturnStatement - 13:16 - Could not infer a return type

INFO: MixedInferredReturnType - 5:26 - Could not verify return type 'B' for A::getB

[MauricioFauth]

Here's a simpler example: https://psalm.dev/r/652f9d7938

[psalm-github-bot[bot]]

I found these snippets:

https://psalm.dev/r/652f9d7938

<?php

function counter(): int {
    static $i = 0;
    return $i++;
}

Psalm output (using commit 3c90054):

INFO: MixedOperand - 5:12 - Left operand cannot be mixed

INFO: MixedAssignment - 5:12 - Unable to determine the type that $i is being assigned to

INFO: MixedReturnStatement - 5:12 - Could not infer a return type

[discordier]

Even simpler, also occurs in global scope.

https://psalm.dev/r/0ec3512e62

[psalm-github-bot[bot]]

I found these snippets:

https://psalm.dev/r/0ec3512e62

<?php

static $counter = 0;
$counter++;

Psalm output (using commit 4b2c698):

INFO: MixedOperand - 4:1 - Left operand cannot be mixed

INFO: MixedAssignment - 4:1 - Unable to determine the type that $counter is being assigned to

[rzvc]

Related: #3101