We're still a very long way from tolerant of weird SMF files (libsmf takes a "crash if input is not exactly perfect" philosophy, if we're going to be polite and elevate such a thing to "philosophy"), but at least we'll get what's there from files truncated by old broken versions of Ardour or other situations.
This is a stripped down version of libsmf 1.2 by Edward Tomasz Napiera for internal use by Evoral. See COPYING for licensing information. The complete version can be found at <http://libsmf.sf.net>.