[Maxima-bugs] [ maxima-Bugs-2943400 ] 'linel' command can crash 'maxima'

[SourceForge.net <no...@so...>]

Bugs item #2943400, was opened at 2010-01-31 23:42
Message generated for change (Comment added) made by sergeiste
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2943400&group_id=4933

Please note that this message will contain a full copy of the comment thread,
including the initial issue submission, for this request,
not just the latest update.
Category: Xmaxima or other UI
Group: None
Status: Open
Resolution: Wont Fix
Priority: 5
Private: No
Submitted By: Sergei (sergeiste)
Assigned to: Nobody/Anonymous (nobody)
Summary: 'linel' command can crash 'maxima'

Initial Comment:
I am new to 'maxima'. As I understand it, 'linel' is supposed to change assumed terminal length -> change wrapping of displayed lines.

Here is an example of scree session which crashes 'maxima':

"
/mnt/sdb8/sergei/AFSWD_debug/install/rlwrap-0.36/binsh/rlwrap -D -A /mnt/sdb8/sergei/AFSWD_debug/install/maxima-5.20.1/binsh/maxima
Maxima 5.20.1 http://maxima.sourceforge.net
using Lisp SBCL 1.0.34
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) linel: 200000000;
Heap exhausted during garbage collection: 0 bytes available, 8 requested.
 Gen StaPg UbSta LaSta LUbSt Boxed Unboxed LB   LUB  !move  Alloc  Waste   Trig    WP  GCs Mem-age
   0:     0     0     0     0     0     0     0     0     0        0     0  2000000    0   0  0.0000
   1:     0     0     0     0     0     0     0     0     0        0     0  2000000    0   0  0.0000
   2: 112602     0     0     0 74809    10     0     0     0 306433880 24744  2000000    0   0  1.0145
   3:     0     0     0     0     0     0     0     0     0        0     0  2000000    0   0  0.0000
   4:     0     0     0     0     0     0     0     0     0        0     0  2000000    0   0  0.0000
   5:     0     0     0     0     0     0     0     0     0        0     0  2000000    0   0  0.0000
   6:     0     0     0     0 11071  2106     0     0     0 53972992     0  2000000 10995   0  0.0000
   Total bytes allocated    = 536821152
   Dynamic-space-size bytes = 536870912
GC control variables:
          *GC-INHIBIT* = true
          *GC-PENDING* = in progress
 *STOP-FOR-GC-PENDING* = false
fatal error encountered in SBCL pid 19049(tid 3085022912):
Heap exhausted, game over.

Welcome to LDB, a low-level debugger for the Lisp runtime environment.
ldb>
".

In my opinion changing line length is a simple operation and shouldn't crash a tool.



----------------------------------------------------------------------

>Comment By: Sergei (sergeiste)
Date: 2010-02-01 05:47

Message:
Regarding "You are mistaken that maxima is not using the value" - now that
I was explained in another bug report of mine about 2d display and
centering by default, I understand that the value is used. And altogether
the _defaults_ (i.e. default use of 2d display/centering) are of poor
choice.

I was very much surprised how quickly I managed to crash 'maxima' just
trying to adjust display settings. I would understand a crash due to lack
of memory while processing a complex expression or, in general, solving a
complex problem,

A crash during adjustment of display settings simply undermines trust.

If you can't change code, please at least update the documentation to
clearly explain the likely limits and implications.

----------------------------------------------------------------------

Comment By: Raymond Toy (rtoy)
Date: 2010-02-01 04:24

Message:
You are mistaken that maxima is not using the value.  The value is set, and
maxima wants to print out the value of linel now.  Hence the new value is
being used.

I suppose it's possible to add a check that linel will be some reasonable
value.

----------------------------------------------------------------------

Comment By: Sergei (sergeiste)
Date: 2010-02-01 02:46

Message:
In any normal language/tool just _setting_ line length _without_ _using_
the setting should crash the tool. The fact that just _setting_ line length
crashes the tool tells that something is implemented in a terribly wrong
manner inside the tool.

----------------------------------------------------------------------

Comment By: Dieter Kaiser (crategus)
Date: 2010-02-01 01:19

Message:
Yes, linel is the assumed width (in characters) of the console display (See
the manual or type ? linel to get the documentation).

The default value is 79. Perhaps a value of 100 or 200 might be useful for
your display too. 
But I can not imagine that a value of 2*10^8 is useful. I think it is a
curiosity to try such a huge value.

Closing this bug report as "wont fix".
Dieter Kaiser

----------------------------------------------------------------------

You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=104933&aid=2943400&group_id=4933