snprintf(3) doesn't set errno in the tested cases.
- If the same argument reference (for example %1) was specified more than
once, the command didn't necessarily fit to the final command buffer. Fix
this using a dynamic sbuf buffer. Add a few regression tests for the case.
PR: bin/95079
No objections: freebsd-hackers
of the recent WARNS commits. The idea is:
1) FreeBSD id tags should follow vendor tags.
2) Vendor tags should not be compiled (though copyrights probably should).
3) There should be no blank line between including cdefs and __FBSDIF.