[mapserver-dev] Offset x -99 AGG crash

[thomas bonfort]

thanks for reporting.
I'll have a look and commit asap.

--
thomas

On Mon, Nov 24, 2008 at 15:47, Torsten Weber <TWeber at traffic-consult.de> wrote:
> Hi all,
>
> I don't know, if this is the correct way to report this.
>
> Mapserver runs on a segfault in the following very special case using the agg
> renderer (GD Renderer works).
> Possibly this stands in context with #2732 and #2659 (discussed
> fixes/modifications are applied):
>
> We have a line layer which has some lines with only two points at the same
> location. (not really meaningful, I know) Normal rendering works, rendering
> with "OFFSET x -99" crashes.
>
> I had a look at the source and found a simple solution. There is a Query at
> maputils.c at line 1493 (from the 5.2 final source) to ignore duplicate
> points. In this special case it reduces the line to one point and mapserver
> crashes.
>
> I've changed the line from
>  if (dx==0) {
>    if (dy==0) {
>      continue;
>    }
>  ....
> to
>  if (dx==0) {
>    if (dy==0 && first==0) {
>      continue;
>    }
>  ...
> so only duplicated points in the middle of a line are ignored and the chrash
> disappears. Tested with shp2img and php_mapscript.
>
> Our Environment:
> SuSE Linux 10.3 with kernel 2.6.22.18 64bit
> Intel Quadcore
> 4GB RAM
> MapServer version 5.2.0 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP
> OUTPUT=SVG SUPPORTS=PROJ SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=ICONV
> SUPPORTS=WMS_SERVER SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER
> SUPPORTS=WFS_CLIENT SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=THREADS
> INPUT=TIFF INPUT=EPPL7 INPUT=ORACLESPATIAL INPUT=OGR INPUT=GDAL
> INPUT=SHAPEFILE
>
> Regards,
>
> Torsten Weber
> --
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