Re: Possible SERIOUS bug in alpha6

• Date: Wed, 17 Jan 1996 17:54:00 PST
• From:
  Pavel Curtis <pavel@parc.xerox.com>
• Cc: MOO-Cows.PARC@xerox.com
• In-Reply-To: "sysop@calbbs.com's message of \"Wed, 17 Jan 1996 17:33:04 PST\" <TCPSMTP.16.1.17.-15.33.4.2239992234.191293@bbs.calbbs.com><f18mcke"

sysop@calbbs.com writes:
> I had some verb code mysteriously "morph" on me tonight.  I had been
> implementing the new {arg,arg,arg}=args; logic in a multitude of verbs...

There is, indeed, quite a serious bug in the implementation of scattering
assignment; in particular:
	a) In a !d verb, if there's either too few or too many list elements
	   for the given list of targets, the server will end up in a very
	   seriously bogus situation, reading and executing putative `opcodes'
	   taken from the *middle* of the SCATTER instruction.  In short: it
	   will be trying to execute essentially random instructions, almost
	   certainly with disastrous results.
	b) In any scattering assignment, if the right-hand side evaluates to a
	   non-list, the server will read putative `list elements' from random
	   locations in memory.
These bugs are almost certainly the cause of both Kipp's and Brian's problems
with the server.

I am working on a patch for these problems and will post it ASAP.  Until then,
I recommend against the use of scattering assignment.

	Pavel

• Possible SERIOUS bug in alpha6
• From: sysop@calbbs.com

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