curl_getinfo($ch, CURLINFO_CONTENT_TYPE) returns false when Content-Type header is not set

Description

The following code:

<?php
$ch = curl_init();
$url = 'https://epapucs.hu/wp-content/uploads/2024/11/F318482161_2.webp';

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, $url);
curl_exec($ch);

$ct = curl_getinfo($ch, CURLINFO_CONTENT_TYPE);

var_dump($ct);

$info = curl_getinfo($ch)['content_type'];

var_dump($info);

curl_close($ch);

Resulted in this output:

bool(false)
NULL

I'd expect these two values to be the same. It's hard to handle errors when a false value is returned when there's no error.

These are the first elements of curl_getinfo associative_array:

array(41) {
  ["url"]=>
  string(63) "https://epapucs.hu/wp-content/uploads/2024/11/F318482161_2.webp"
  ["content_type"]=>
  NULL
  ["http_code"]=>
  int(200)

PHP Version

PHP 8.4.1

Operating System

macOS 15.1

The report provides no repository file or test entry point. Start by running the supplied PHP reproduction against a response without a Content-Type header, then inspect how the scalar and associative curl_getinfo results are produced. Done means the two forms have consistent, documented behavior for this response.