Description of problem: Trying to fsck my /dev/sda1 lets fsck.vfat consume 100% CPU without any disk reads. strace does not show any syscalls after some read(). Version-Release number of selected component (if applicable): dosfstools-3.0.16-2.fc19.x86_64 I dd'ed and xz'ed the partition image. Maybe you can debug fsck.vfat with that. Dropbox link sent to jskarvad in private chat. Please only share with debuggers.
It does seem as ABI mismatch and it seems it was resolved by the latest rebuild. I am unable to reproduce it with the dosfstools-3.0.16-3.fc19. I rechecked with the valgrind, there are some memory leaks due to poor coding (I am going to resolve them later), but none of them should be fatal.
*** Bug 950012 has been marked as a duplicate of this bug. ***
dosfstools-3.0.16-3.fc19 has been submitted as an update for Fedora 19. https://admin.fedoraproject.org/updates/FEDORA-2013-7251/dosfstools-3.0.16-3.fc19
I added this BZ to dosfstools-3.0.16-3.fc19 errata, feel free to reopen if the problem persists.
dosfstools-3.0.16-3.fc19 has been pushed to the Fedora 19 stable repository. If problems still persist, please make note of it in this bug report.