[net.bugs.4bsd] setjmp/longjmp change in 4.1c

smb@ulysses.UUCP (08/03/83)

Due to a change in the implementation of longjmp, certain incorrect
behavior causes trouble in 4.1c.  In particular, some programs (such
as SCCS) say

	longjmp(JBF);

instead of the correct

	lonjmp(JBF, 1);

In 4.1 BSD (and System V), this works, because any non-zero value will
generally work -- and if the stack contains random garbage instead of a
1, there's no trouble.  Longjmp even checks for a zero second argument,
and forces it to 1 in that case.

4.1c longjmp, however, unwinds the stack a frame at a time.  This tends
to confuse matters somewhat more.....

Thanx to Bob Rodriguez (ulysses!rr) for finding the problem.

		--Steve