PHP fgetcsv() behavior on empty lines

The PHP documentation for fgetcsv() states that A blank line in a CSV file will be returned as an array comprising a single null field, and will not be treated as an error. Here’s a quick demonstration of this behavior.

fgetcsv.php:

<?php
 
while ($fields = fgetcsv(STDIN, 0, ';'))
  print_r($fields);
 
exit(0);

Execute the script and feed it some CSV with empty lines:

php -q fgetcsv.php
"Veld 1";"Veld 2";"Veld 3";;"Veld 5"
 
"Field 1";;"Field 3";"Field 4";
;;;;
;"Campo 2";;;"Campo 5"

After pressing Ctrl+D, I’m presented with the following output:

Array
(
    [0] => Veld 1
    [1] => Veld 2
    [2] => Veld 3
    [3] => 
    [4] => Veld 5
)
Array
(
    [0] => 
)
Array
(
    [0] => Field 1
    [1] => 
    [2] => Field 3
    [3] => Field 4
    [4] => 
)
Array
(
    [0] => 
    [1] => 
    [2] => 
    [3] => 
    [4] => 
)
Array
(
    [0] => 
    [1] => Campo 2
    [2] => 
    [3] => 
    [4] => Campo 5
)
Array
(
    [0] => 
)

This behaviour on empty lines is a little bit annoying if you want to test if the line is empty():

$a = array(null);
print_r($a);
 
if ( empty($a) )
  echo '$a is empty';
else
  echo '$a is not empty';
 
echo "\n";

This code will print:

Array
(
    [0] => 
)
$a is not empty

Hence, the following function:

/**
 * This function tests if the given array (as returned by fgetcsv())
 * is the result of an empty line in the CSV file.
 *
 * It does not work for lines that contain only delimiters.
 * From the POV of this function, these are simply records with
 * many empty fields.
 */
function fgetcsv_empty_line($row_array) {
  return ( !isset($row_array[1]) and empty($row_array[0]) );
}

Now, if I change the call to empty() in my test to a call to fgetcsv_empty_line():

$a is empty