[Mapserver-dev] bug in mapswf.c (msDrawLabelCacheSWF)?

[Yewondwossen Assefa]

Hi There,

  Thanks for pointing this out.

  I have done the modifications to the source code to avoid the problem.

   Although the changes you did should avoid the crash, there was a 
potential error when assigning image->img.swf->nCurrentMovie = 
cachePtr->layerindex since the movie index and the layer index are not 
in sync. The crash happened for layerindex > nLayerMovies but the 
assignment could also be wrong without a crash.

If you are willing to do the tests please contact me personally and I 
will send you the modifications before commiting the code. If not I will 
enter a bug and  commit the code when I will do proper testing on my side.

Late


Steve Spicklemire wrote:

> 
> Hi (again) Mapserver folks,
> 
> I have a map where msDrawLabelCacheSWF segfaults mapserver when 
> OUTPUT_MOVIE=MULTIPLE. The problem is that if the last layer is not 
> drawn, drawMap still tries to cache labels on that layer, and 
> (mistakenly) tries to access the movie for that layer, which immediately 
> segfaults since there is no movie for that layer (drawlayer never calls 
> startlayer if the layer isn't visible).
> 
> Anyway... this patch stops the crashing for me:
> 
> Index: mapswf.c
> ===================================================================
> RCS file: /data2/cvsroot/mapserver/mapswf.c,v
> retrieving revision 1.31
> diff -C3 -r1.31 mapswf.c
> *** mapswf.c    16 Jul 2003 16:44:58 -0000      1.31
> --- mapswf.c    2 Dec 2003 20:53:18 -0000
> ***************
> *** 2119,2128 ****
>   /*      set the current layer so the label will be drawn in the       
>   */
>   /*      using the correct SWF handle.                                 
>   */
>   /* 
> ==================================================================== */
> !         image->img.swf->nCurrentMovie = cachePtr->layerindex;
> 
> !         //msImageStartLayerSWF(map, layerPtr, image);
> !         image->img.swf->nCurrentLayerIdx = cachePtr->layerindex;
>   /* 
> ==================================================================== */
>   /*      at this point the layer (at the shape level is closed). So    
>   */
>   /*      we will open it if necessary.                                 
>   */
> --- 2119,2134 ----
>   /*      set the current layer so the label will be drawn in the       
>   */
>   /*      using the correct SWF handle.                                 
>   */
>   /* 
> ==================================================================== */
> !
> !       if (cachePtr->layerindex >= image->img.swf->nLayerMovies) {
> !         continue;
> !       }
> !
> !       image->img.swf->nCurrentMovie = cachePtr->layerindex;
> !
> 
> !       //msImageStartLayerSWF(map, layerPtr, image);
> !       image->img.swf->nCurrentLayerIdx = cachePtr->layerindex;
>   /* 
> ==================================================================== */
>   /*      at this point the layer (at the shape level is closed). So    
>   */
>   /*      we will open it if necessary.                                 
>   */
> 
> 
> I've not seen any trouble with it so far..
> 
> -steve
> 
> _______________________________________________
> Mapserver-dev mailing list
> Mapserver-dev at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-dev
> 


-- 
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Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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