Description:
------------
The behavior of fwrite/fputcsv and SplFileObject::fwrite and SplFileObject::fputcsv have changed in PHP7.4 when used with a non writable stream. 

see https://3v4l.org/ifpaa

Reading the changelog I fail to see where this is mention so is it the now expected behaviour from PHP7.4+ or is it a bug ?

Test script:
---------------
<?php

$spl = new SplFileObject('php://temp', 'r');
$fh = fopen('php://temp', 'r');

var_export([
    'SplFileObject::fputcsv result on failure' => $spl->fputcsv(['foo', 'bar']),
    'SplFileObject::fwrite result on failure' => $spl->fwrite('foo'),
    'fputcsv result on failure' => fputcsv($fh, ['foo', 'bar']),
    'fwrite result on failure' => fwrite($fh, 'foo'),
]);

Expected result:
----------------
array (
  'SplFileObject::fputcsv result on failure' => 0,
  'SplFileObject::fwrite result on failure' => 0,
  'fputcsv result on failure' => 0,
  'fwrite result on failure' => 0,
)

Actual result:
--------------
array (
  'SplFileObject::fputcsv result on failure' => -1,
  'SplFileObject::fwrite result on failure' => false,
  'fputcsv result on failure' => false,
  'fwrite result on failure' => false,
)