php static::inside 匿名函数

Question

代码在本地机器上运行良好，但在远程服务器上却很奇怪。远程服务器上的 PHP 5.5.9，本地机器上的 PHP 5.5.28远程服务器(PHP 版本、服务器配置等)出现这种奇怪行为的原因是什么？

class A {
...
    public static f1(){
        ...
        self::$f2 = static::f2();
        ...
    }
    ...
    protected static function f2() {
        ...
        var_dump(static::class); // returns B on the local machine and on the remote server

        $f3 = function () {
            var_dump(static::class); // returns B on the local machine and returns A on the remote server
            ...
            $data = static::f4() ...
            ...
        };
        ...
    }
...
}
class B extends A{...}
...
self::$B = B::f1();

Answer 1

这是一个 known bug已在 PHP 5.5.14 中修复.以下是原始错误报告的引述:

Closures do not correctly capture the late bound class (static::) in some cases

Description:

When a PHP closure is created, it is supposed to capture the late bound class of the enclosing function. There are a number of cases involving derived classes and static methods or static closures (or both) where it doesn't work correctly.

The test script I've included demonstrates the problem. I've tested it on PHP 5.6.0alpha1, but I can also reproduce the problem on various builds of PHP 5.5.