get_file_data() is obtuse

[nacin]

get_file_data() employs two odd-looking constructs. This is to make keys equal the values:

$extra_headers = array_flip( $extra_headers );
foreach( $extra_headers as $key=>$value ) {
	$extra_headers[$key] = $key;
}

A single array_combine() will clean this up.

Later, it uses ${$field}, followed by a return compact( array_keys( ) ), rather than simply building the output array in the format for which it is returned.

Attached is a simple patch that shortens the function while making it easier to understand, and introduces some small performance gains.

In fairness, array_combine() was not available in PHP4.

In [20088]:

Use array_combine() in get_file_data() and avoid variable variables when an array is just fine. fixes #20126.