Description:
------------
key function within foreach array does not start from the very beginning of the array instead it starts from the 2nd element

Reproduce code:
---------------
$courses= array(                                                                                                                                             
               1=>"test",                                                                                                                                    
               2=>"test2",                                                                                                                                   
               3=>"test3"                                                                                                                                    
);                                                                                                                                                           
echo key($courses)."\n";                                                                                                                                     
foreach($courses as $key=>$course){                                                                                                                          
    echo $key ." ". $course."\n";                                                                                                                            
                                                                                                                                                             
}                                                                                                                                                            
reset($courses);                                                                                                                                             
echo "\n";                                                                                                                                                   
echo key($courses)."\n";                                                                                                                                     
foreach($courses as $course){                                                                                                                                
    echo key($courses) ." ". $course."\n";                                                                                                                   
    next($courses);                                                                                                                                          
                                                                                                                                                             
}     

Expected result:
----------------
1
1 test
2 test2
3 test3

1
1 test
2 test2
3 test3

Actual result:
--------------
1
1 test
2 test2
3 test3

1
2 test
3 test2
 test3