BIG bug!

[Dave Sainty <David.Sainty@Comp.VUW.AC.NZ>]

This bug has a very weird effect that could cause a lot of strife! The
effect appears to be that at the end of .'ing a script (including
login scripts), zsh is likely to jump back into the middle of the
script and start again! This causes infinite loops, or weird errors
with no apparent cause (I could not see where the unmatched " was,
because my login script was being jumped into halfway through a line
with a " near the start!)

At the end of the letter is a uuencoded/gzipped script that will show
the bug if "zsh -f script-name"'d. It is my login script with
everything removed that doesn't affect the bug. Also, the exact size
of the file is vital, which is why I'm mailing it as binary. It has a
"return" statement strategically placed in the middle of the script,
that xtrace shows is executed at the end of the script! Magic! :-)
This is visible on Solaris and Alpha/OSF boxes at any rate.

This is new since beta 8. In fact, it seems to be Peter Stephenson's
fault, if I may point the finger... ;-) The fault appears after
applying patch 6160 to exec.c (In which a typo was fixed also by patch
6197, but this does not solve the problem here).

This code does very little new, simply exiting under certain
conditions, so there must be a logic problem in the condition it exits
on. But I don't have a clue what is going on in this code, so I'll
leave it to someone who does. (Peter?)

And yeah.... That did take a lot of hunting! But I have so much work
to do, I was just looking for a reason to procrastinate! :-)

Dave.