Yesterday I found some time to send some patches for btrfs-progs upstream. Unfortunately the information on the btrfs wiki pages about the source code repositories are completely outdated, either the repo didn't exist or the branch wasn't there as in case of the 'for-chris' branch of the 'Integration repository'. Finally I send them against the repo of Chris Mason listed at git.kernel.org.
The patches fix some possible segfaults and some compiler warnings, you can find them at the mailing list.