@ryandemmer This works, i tuned the regex a bit. Here is my proposal:

preg_match_all('#(?:[^\s]+)\s*(?:[\d\.]+[wx])?(?:\,\s*)?#i', $match[1], $matches);

foreach ($matches[0] as &$src)
{
    $src = preg_replace('#^(?!/|' . $protocols . '|\#|\')(.+)#', $base . '$1', $src);
}

return ' srcset="' . implode($matches[0]) . '"';

@steffans - Thanks, that looks OK. Perhaps we can neaten things up a bit like this:

preg_match_all('#(?:[^\s]+)\s*(?:[\d\.]+[wx])?(?:\,\s*)?#i', $match[1], $matches);

foreach ($matches[0] as &$src)
{
    $src = preg_replace('#^(?!/|' . $protocols . '|\#|\')(.+)#', $base . '$1', $src);
    $src = trim($src);
}

return ' srcset="' . implode(' ', $matches[0]) . '"';

The spaces are not required if the url contains a descriptor, but it gives a consistent result if the original value is missing spaces between some urls.

@ryandemmer Sure, this works. My goal was it to keep the original srcset as it was generated without normalizing anything. In your case you can move the trim() as preg_replace $src.

$src = preg_replace('#^(?!/|' . $protocols . '|\#|\')(.+)#', $base . '$1', trim($src));

My goal was it to keep the original srcset as it was generated without normalizing anything

I agree. I will revert the change to use your original code.

I see that the version 3.8.2 is in preparing. I posted the issue #18269 with the bug report in version 3.8.1 and I have interest that the bug will be fixed. The pull request, which fixes the bug, was prepared almost one month ago. Why it will be not merged? Is there are exist some reason not merging it?

Why it will be not merged? Is there are exist some reason not merging it?

All pull requests require tests from two individuals other than the person who created it to test and make sure that it fixes the reported issue without introducing other issues. Most pull requests that don't get merged are usually due to a lack of testing or interest.

I have tested this item ✅ successfully on 022419e

I tested the changes suggested by the pull request and can confirm that it fixes the bug reported in the issue #18269

@mbabker Thank you for clearing! I verified the latest state of changes suggestion by the pull request and everything is working OK.

I have tested this item ✅ successfully on 022419e

Srcset broke images on mobile devices with the update to 3.8.2 because the space was trimmed. I added this update and it fixed my broken images.

Ready to Commit after two successful tests.

when will this fix be released?