Apparently the kernel module to read hfs-formated disks is less functional than the one for hfsplus-formated disks. I managed to crash my system mounting an hfs-formatted CD. A good alternative are the hfs utilities (hfsutils). There is also an easy GUI for them called xhfsutil.
UPDATE (25.12.2023): I needed to mount an HFS+ formatted partition from a 2011 MacbookPro (macOS Sierra) to copy some data before disposing of it. Strangely, my Ubuntu 20.04 still cannot automatically manage to mount these if they are wrapped in a CoreStorage volume (which started in macOS 10.10). In order to mount these, you need to specify a size limit (for details, see https://superuser.com/questions/961401/mounting-hfs-partition-on-arch-li...). To figure out the exact size limit, you use testdisk. You need to find out the size of the partition (which testdisk gives you in sectors). You need to multiply the sector number with the sector size (which you can figure out with fdisk; it's usually 512). The command for mounting the partition is:
mount -t hfsplus -o ro,sizelimit=N /dev/sdXn /mnt