Bug #74558 [Asn->Csd]: Can't rebind closure which returns by Closure::fromCallable()

From: Date: Mon, 16 Nov 2020 13:35:27 +0000
Subject: Bug #74558 [Asn->Csd]: Can't rebind closure which returns by Closure::fromCallable()
References: 1  Groups: php.bugs 
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Edit report at https://bugs.php.net/bug.php?id=74558&edit=1

 ID:                 74558
 Updated by:         cmb@php.net
 Reported by:        igorchernin at yahoo dot com
 Summary:            Can't rebind closure which returns by 
                     Closure::fromCallable()
-Status:             Assigned
+Status:             Closed
 Type:               Bug
 Package:            Scripting Engine problem
 Operating System:   Windows
 PHP Version:        7.1.4
 Assigned To:        cmb
 Block user comment: N
 Private report:     N

 New Comment:

Automatic comment on behalf of cmbecker69@gmx.de
Revision: http://git.php.net/?p=php-src.git;a=commit;h=78773890f6b0d82b29e0b869f3f3b22174cea217
Log: Fix #74558: Can't rebind closure returned by Closure::fromCallable()


Previous Comments:
------------------------------------------------------------------------
[2020-11-12 12:49:35] cmb@php.net

The following pull request has been associated:

Patch Name: Fix #74558: Can't rebind closure returned by Closure::fromCallable()
On GitHub:  https://github.com/php/php-src/pull/6424
Patch:      https://github.com/php/php-src/pull/6424.patch

------------------------------------------------------------------------
[2017-05-08 21:35:06] igorchernin at yahoo dot com

Thank you, for the clarification. So as I undestood. 
If I use the Closure
$cl2 = function () {
    return $this->name;
};
It has an object scope (because $cl2 is an object of Closure).
But Closure::fromCallable() creates a Closure from current scope which is not an object scope in
case of freestanding function. And $this inside freestanding function is not valuable. Maybe it
makes sense to add the information to manual or restrict to use $this inside freestanding functions.
Thank you.

------------------------------------------------------------------------
[2017-05-08 20:52:52] nikic@php.net

The error message should be changed to not mention ReflectionFunctionAbstract::getClosure(), but
otherwise the behavior is intentional. Freestanding functions don't have an object scope, so
you cannot bind one.

------------------------------------------------------------------------
[2017-05-08 20:45:21] igorchernin at yahoo dot com

Description:
------------
---
From manual page: http://www.php.net/closure.fromcallable
---
Get error:  Cannot rebind scope of closure created by ReflectionFunctionAbstract::getClosure()

I am getting the error after converting function to Closure and after rebind the Closure to some
object.
I can't bind (and also bindTo) closure which returned by Closure::fromCallable(). 


Test script:
---------------
<?php
class A {
    private $name;
    public function __construct($name)
    {
        $this->name = $name;
    }
}

// test callable
function getName()
{
    return $this->name;
}
$bob = new A("Bob");

$cl1 = Closure::fromCallable("getName");
$cl1 = $cl1->bindTo($bob, 'A');
$result = $cl1();
echo $result

Expected result:
----------------
Bob

Actual result:
--------------
Warning: Cannot rebind scope of closure created by ReflectionFunctionAbstract::getClosure() on line
18


------------------------------------------------------------------------



--
Edit this bug report at https://bugs.php.net/bug.php?id=74558&edit=1


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