🚀 go-pugleaf

 In article <199511110147.AA00930@moroder.demon.co.uk>
  Stephen Mulrine <robotron@moroder.demon.co.uk> said:-

>In article <816033810_OASIS_@swampdog.demon.co.uk>, 
>guy@swampdog.demon.co.uk (me!) wrote:
>
>> In article <5936_pbaker@mettav.demon.co.uk>
>>  pbaker@mettav.demon.co.uk (Paul Baker) said:-
>>
>>>It works 1001f the time now..
>>          ^^^^^
>>Ah! - the newsgroup mutation I've been waffling on about. Was this 
>>originally:
>>It works 100% of the time now..
>>Anyone else experiencing this?
>
>Yes, I've seen it a few times.  I'm not sure where the articles are 
>getting corrupted, but I have an idea what's causing it: somewhere 
>along the line is a C program with a bug (or a program compiled with a 
>bugged compiler written in C).  What's taking place is something like
>    fprintf(fp,line)          /* very bad */
>instead of
>    fprintf(fp,"%s",line)     /* okay */

I can confirm this. Anybody using NOS can also do so by doubling up 
the % signs. To get the "It works 100% of the time" line printed 
correctly you actually need to type "It works 100%% of the time" (I 
had to type four % signs to get the two % signs you are now 
seeing!). For the non C programmers out there, it is suffice to say 
that this will stop the buggy NOS line pulling non existent arguments 
off the stack.

>This can't be a problem at the Demon end - they'd surely have noticed 
>by now.  It's not at the recipient's end - I've seen the problem using 
>both NOS/SNEWS on the ST and Free Agent on the PC.  And crucially, 
>Paul Baker's article arrived corrupted and Guy Harrison's arrived 
>intact, although they both used percentage signs.  The problem must 
>lie at the sender's end - either with the news-posting software used 
>(easily checked by examining the files in your spool directory before 
>connecting) or in one or more versions of NOS itself.

I am now certain where the problem lies. For me, it originated when 
posting an article to comp.lang.c. First of all it just caused 
mutations then a later article persistently caused NOS 0.42 to bomb 
out, so badly in fact, that it took out the whole of NOS and Oasis. I 
wish I still had that article but I would guess it contained %s or 
%r.

The crash occurred after nntp connected, after the "usage GROUP" 
message but before any other text was output. This was with nntp trace 
level 3. It does *not* occur with email and I have no reason to think 
it occurs when nntp is recieving news either. It is only when nntp 
posts. ie:

Connected
Usage GROUP
(2 bombs - bus error)

This bug will also have ramifications for UU encoded postings.

As the cure is simple and the effects potentially disastrous, could I 
now request on behalf of all NOS users, a re-compilation of the 
offending source code and a posting of "NOS 0.42-and-a-half".


__

Guy Harrison

guy@swampdog.demon.co.uk