Description:
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Hi,

documentation says that valid callables might be string name of functions, closure, or:

"A method of an instantiated object is passed as an array containing an object at index 0 and the method name at index 1. Accessing protected and private methods from within a class is allowed.

Static class methods can also be passed without instantiating an object of that class by passing the class name instead of an object at index 0. As of PHP 5.2.3, it is also possible to pass 'ClassName::methodName'."

ref http://php.net/manual/en/language.types.callable.php

However "is_callable" does not behave as I would expect when passing an array with a class and a non static method, true is returned instead of false.

Is this an expected behavior? Shouldn't we rely on "is_callable" before calling "call_user_func"?

If not please update or let me know if I should open another issue for:

http://php.net/manual/en/function.is-callable.php

since it currently says:

"Verify that the contents of a variable can be called as a function. This can check that a simple variable contains the name of a valid function, or that an array contains a properly encoded object and function name."

If we change the test script I provide to "echo" a regular string like "object call" instead of using an object property, the string is printed after the warning triggered by "is_callable", so "call_user_func" is actually called.

Since I'm just a php beginner and don't know anything about the internal, I don't know if the error comes with "is_callable" because "call_user_func" is actually callable or if it comes from "call_user_func" because "is_callable" returns true.

But my guess is that "call_user_func" should test internally if the array is callable (second case), and throw an invalid argument exception instead.

The a user like me should be able to use "is_callable" before using it and getting the invalid argument exception.

However the current fatal error got from the provided test script looks really wrong to me.

Note that it happens in my local environment but not on my server holding the script online.

Thank you for your time reading this and for working on PHP, it is an awesome open-source project!

(sorry for any mistake, this is my first issue report and I'm not a native speaker).

Test script:
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http://heahprod.com/php/bug-is_callable.php

Expected result:
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static call static call object call object message

Actual result:
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static call 
Strict Standards: call_user_func() expects parameter 1 to be a valid callback, non-static method SomeClass::someObjectMethod() should not be called statically in /test.php on line 39
object call 
Strict Standards: call_user_func() expects parameter 1 to be a valid callback, non-static method SomeClass::getMessage() should not be called statically in /test.php on line 45

Fatal error: Using $this when not in object context in /test.php on line 19