Description:
------------
The call of test() results into an endless loop. The first for() works well, the for() in the function is the problem.
And the Problem appears even if the first for() is left out.

Reproduce code:
---------------
<?PHP
    

$arr = array ('a' => 1, 'c' => 2);    

for (reset ($arr); $key = key ($arr); next ($arr)) {   
   echo $key;   
}   

echo "PING";

function test() {
   global $arr;
   for (reset ($arr); $key = key ($arr); next ($arr)) {
      echo $key;
   }
}   
    
test();
  
?>

Expected result:
----------------
Output of "acPINGac"

Actual result:
--------------
Endless Loop

Output of "acPINGaaaaaaaaaaaaa ... to be continued"