Description:
------------
If no error_reporting is defined ( not in php.ini, not in .htaccess, not in source)
then ini_get('error_reporting') returns an empty string.
however, error_reporting() does return a value ("22519" on 7.1.4)

in addition phpinfo()  shows 

master value: "no value"  
local Value: "22519"

after setting error_reporting to the current error_reporting() value 
the ini value is suddenly set 




Test script:
---------------
<?php
echo "<pre>";

var_dump(ini_get('error_reporting'));
var_dump(error_reporting());

error_reporting(error_reporting());

var_dump(ini_get('error_reporting'));
var_dump(error_reporting());


Expected result:
----------------
/var/www/127.0.0.1/index.php:4:string '22519' (length=5)
/var/www/127.0.0.1/index.php:5:int 22519

/var/www/127.0.0.1/index.php:8:string '22519' (length=5)
/var/www/127.0.0.1/index.php:9:int 22519


Actual result:
--------------
/var/www/127.0.0.1/index.php:4:string '' (length=0)
/var/www/127.0.0.1/index.php:5:int 22519

/var/www/127.0.0.1/index.php:8:string '22519' (length=5)
/var/www/127.0.0.1/index.php:9:int 22519