Re: [Gnuplot-developers] [ gnuplot-Bugs-1194035 ] gnuplot 4.1 coredump with hidden3d set

[Ethan M. <merritt@u.washington.edu>]

On Monday 02 May 2005 01:32 pm, Way...@su... wrote:
> Bugs item #1194035, was opened at 2005-05-02 13:32
> Message generated for change (Tracker Item Submitted) made by Item Submitter
> You can respond by visiting: 
> https://sourceforge.net/tracker/?func=detail&atid=102055&aid=1194035&group_id=2055

> Summary: gnuplot 4.1 coredump with hidden3d set

>    We think this is a 4.1 bug because we have been
>    running the same a.gp file using gnuplot4.0.0
>    for months...without problems. and i think gnuplto4.1
>    should not core dump but gives a meaningful
>    error msg before it exits.

It turns out that this was a "hidden bug".
The error was already present in 4.0, but it did not cause
a segfault.   Consider the following patch a band-aid, rather than a 
proper fix, because I do not yet understand when/why these illegal
vertices are being created in the first place.  I do note, however,
that the other plotting styles were already testing for (thisvertex<0);
it was only POINTSTYLE that failed to check.

--- gnuplot/src/hidden3d.c      2004-11-08 11:27:29.000000000 -0800
+++ gnuplot-cvs/src/hidden3d.c  2005-05-02 15:50:00.619201816 -0700
@@ -1287,6 +1287,8 @@
 
                case POINTSTYLE:
                default:        /* treat all the others like 'points' */
+                   if (thisvertex < 0) /* Ignore invalid vertex; but how does this happen? */
+                       break;
                    store_edge(thisvertex, edir_point, crvlen, lp, above);
                    break;
                } /* switch */



-- 
Ethan A Merritt       merritt@u.washington.edu
Biomolecular Structure Center
Mailstop 357742
University of Washington, Seattle, WA 98195