@Kubik-Rubik
Is there a good way to test it? Or a case that show a error?
The Patch looks good for me

Here is a backport to 2.5: #3466

Actually, you can not test it. It is more a coding standard problem. The Not operator (!) has a higher precedence then the Assignment operator (=). See the operator precedence list for more information: http://www.php.net/manual/en/language.operators.precedence.php

Viktor is right that it's not the best codestyle. However PHP makes it work neverthless
From the note on the page linked:

Although = has a lower precedence than most other operators, PHP will still allow expressions similar to the following: if (!$a = foo()), in which case the return value of foo() is put into $a.

Which means, it's valid code. But adding the brackets would improve readability and be "cleaner" code.
I'm not aware that we have a codestyle rule for that currently, so maybe we want to add that to our rules.

+1 for merge it.

Merged, thanks!

Now for real...

This one should really have become 2 lines. It's just calling for future trouble. Assignments should not be made in ifs.

@beat Yes, agree. I also don't like assignments in if statements.

I also don't like assignments in if statements.

So why not fix it the right way and avoid those assignment in condition ?

@elkuku Yes, should be done for the whole code...