Description:
------------
In the code below, you can see a string called 'foo', if you try to make a strstr, strpos, ereg, ..., to this string you get this error:



It seems that a string ending with '==' it's understand as a function call.

Reproduce code:
---------------
<?php
$foo='asdfdgfsg==';
if (strstr($foo,'==')) $foo=substr($foo(0,strlen($foo)-2));
    
echo $foo;
?>

Expected result:
----------------
asdfdgfsg

Actual result:
--------------
PHP Fatal error:  Call to undefined function asdfdgfsg==() in /usr/home/myuser/test.php on line 3
PHP Stack trace:
PHP   1. {main}() /usr/home/myuser/test.php:0