From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <36c13887672c32979c9849347bc8d07a@google.com>
To: 9fans@cse.psu.edu
Subject: Re: [9fans] acme suicide
From: "rob pike, esq." <r@geekmail.cc>
In-Reply-To: <f3b7bff415d0.f415d0f3b7bf@cwru.edu>
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Date: Mon,  8 Mar 2004 21:28:46 -0800
Topicbox-Message-UUID: 24e66a5a-eacd-11e9-9e20-41e7f4b1d025

> I tried 'Edit , | man 2 9p' in the tag of an acme window and got:
> 
> panic: D2B called on non-block 11a8c8 (double-free?)
> acme 1436: suicide: sys: trap: fault read addr=0x0 pc=0x0003aed5

this is kind of amazing. i was testing something for rsc and crashed acme.
tracked it down, fixed it.  it was a day 1 bug; amazing it had never happened.
then i decided to track down your bug.  turns out it's the same thing.
amazing coincidence.

here's the fix:

r% yesterday -d /sys/src/cmd/acme/elog.c
diff /n/dump/2004/0308/sys/src/cmd/acme/elog.c /sys/src/cmd/acme/elog.c
173c173
< 	if(f->elog.type==Insert && q0==f->elog.q0 && (q0+nr)-f->elog.q0<Maxstring){
---
> 	if(f->elog.type==Insert && q0==f->elog.q0 && f->elog.nr+nr<Maxstring){
r% 

-rob