Re: core dump for lack data of xticlabels()

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

On Thursday 31 July 2008, Shigeharu TAKENO wrote:
> shige 08/01 2008
> ----------------
> 
> The gnuplot of current CVS version may make core dump by the 
> following script which includes the lack data of xticlabels(), 
> but gnuplot-4.2.3 may not:
> 
>  plot '-' using 1:2:xtic(3) w l
>  1 2 tic1
>  2 3 tic2
>  3 6 
>  4 4 tic4
>  5 5 tic5
>  e

Thank you for the bug report.

Rather than storing a NULL label and having to test for NULL every time
the list of labels is scanned, I think it would be better not to store a
NULL label at all.

Something like this (not tested thorougly, but seems foolproof):

--- ../../gnuplot/src/axis.c	2008-06-05 21:15:58.000000000 -0700
+++ ./axis.c	2008-07-31 21:39:09.000000000 -0700
@@ -1618,6 +1618,9 @@ add_tic_user(AXIS_INDEX axis, char *label
     struct ticmark *tic, *newtic;
     struct ticmark listhead;
 
+    if (!label)
+	return;
+
     /* Mark this axis as user-generated ticmarks only, unless the */
     /* mix flag indicates that both user- and auto- tics are OK.  */
     if (!axis_array[axis].ticdef.def.mix)




>  OS: Solaris 9 (sparc)
>  compiler: gcc-3.4.3 
> 
> The following patch seems to fix it.
> 
> ----- From here -----
> --- axis.c.ORG	Fri Aug  1 12:20:48 2008
> +++ axis.c	Fri Aug  1 13:03:09 2008
> @@ -872,8 +872,12 @@
>  	    if (!inrange(internal, internal_min, internal_max))
>  		continue;
>  
> -	    if (mark->level < 0) /* label read from data file */
> -		strncpy(label, mark->label, sizeof(label));
> +	    if (mark->level < 0) {/* label read from data file */
> +		if (mark->label != NULL) 
> +		  strncpy(label, mark->label, sizeof(label));
> +		else 
> +		  label[0]='\0';
> +	    }
>  	    else if (axis_array[axis].is_timedata)
>  		gstrftime(label, 24, mark->label ? mark->label : ticfmt[axis], mark->position);
>  	    else
> ----- To here -----
> 
> +========================================================+
>  Shigeharu TAKENO     NIigata Institute of Technology
>                        kashiwazaki,Niigata 945-1195 JAPAN
>  sh...@ie...   TEL(&FAX): +81-257-22-8161
> +========================================================+
> 
> -------------------------------------------------------------------------
> This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
> Build the coolest Linux based applications with Moblin SDK & win great prizes
> Grand prize is a trip for two to an Open Source event anywhere in the world
> http://moblin-contest.org/redirect.php?banner_id=100&url=/
> _______________________________________________
> gnuplot-beta mailing list
> gnu...@li...
> https://lists.sourceforge.net/lists/listinfo/gnuplot-beta
> 



-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742