srcset broken with special characters

Hello,

when uploading an image containing “@” in its name and using wp_get_attachment_image_srcset the returned data is always false.

I debugged this and it’s caused by the loop of wp_calculate_image_srcset. Specifically the code between 1078-1080

if ( ! $src_matched && false !== strpos( $image_src, $dirname . $image['file'] ) ) {
			$src_matched = $is_src = true;
		}

While image_src is provided by you and contains the full url with the escaped “@” (%40) the strpos second parameter have the plain @. This causes the src_matched to never get set to true resulting in “return false” later in the code.

https://wordpress.org/plugins/amazon-s3-and-cloudfront/