Segmentation fault with png-inimage exceptions and quantize_force=on

[mko]

MapServer crashes when exception format is set to vnd.ogc.se_inimage and format is png with quantize_force=on. Applies to version 5.4.0-b1 and 5.2.1. No error if gif or jpeg are used as output format or quantize_force=off.

OUTPUTFORMAT
        NAME png
        DRIVER "GD/PNG"
        MIMETYPE "image/png"
        IMAGEMODE RGBA
        EXTENSION "png"
        FORMATOPTION "INTERLACE=OFF"
        FORMATOPTION "QUANTIZE_FORCE=ON"
        FORMATOPTION "QUANTIZE_COLORS=256"
        TRANSPARENT ON
END

$ gdb ./mapserv
...
Starting program: mapserv "QUERY_STRING=...&REQUEST=GetMap&SERVICE=WMS&FORMAT=image/png&EXCEPTIONS=application/vnd.ogc.se_inimage"
[Thread debugging using libthread_db enabled]
[New Thread -1229445456 (LWP 18936)]
Content-type: image/png


Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1229445456 (LWP 18936)]
0x0812ed28 in msSaveImageRGBAQuantized (img=0x81be070, ctx=0x81bdc08, format=0x81ad6e0) at maprgbapng.c:380
380     maprgbapng.c: No such file or directory.
        in maprgbapng.c
(gdb) bt
#0  0x0812ed28 in msSaveImageRGBAQuantized (img=0x81be070, ctx=0x81bdc08, format=0x81ad6e0) at maprgbapng.c:380
#1  0x080a0c91 in msSaveImageGDCtx (img=0x81be070, ctx=0x81bdc08, format=0x81ad6e0) at mapgd.c:3615
#2  0x080a10dd in msSaveImageGD (img=0x81be070, filename=0x0, format=0x81ad6e0) at mapgd.c:3556
#3  0x0808308b in msWriteErrorImage (map=0x81a6bb0, filename=0x0, blank=0) at maperror.c:472
#4  0x08147591 in msWMSException (map=0x81a6bb0, nVersion=65793, exception_code=0x8189143 "LayerNotDefined") at mapwms.c:106
#5  0x0814cdaa in msWMSLoadGetMapParams (map=0x81a6bb0, nVersion=65793, names=0x81a5de0, values=0x81a5f78, numentries=13) at mapwms.c:1117
#6  0x0814f6d9 in msWMSDispatch (map=0x81a6bb0, req=0x81a5dc0) at mapwms.c:3571
#7  0x080e8c0f in msOWSDispatch (map=0x81a6bb0, request=0x81a5dc0, force_ows_mode=0) at mapows.c:67
#8  0x08055b5f in main (argc=2, argv=0xbff07234) at mapserv.c:1253
(gdb) quit

$ ./mapserv -v
MapServer version 5.4.0-beta1 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP OUTPUT=PDF 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=GEOS SUPPORTS=RGBA_PNG 
INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE

[mko]

In msSaveImageRGBAQuantized() gdImageTrueColorPixel() will fail if no layer was rendered (e.g. wrong layer in url). However, gdImagePalettePixel() works:

//int c=gdImageTrueColorPixel(img,col,row);
  int c = (img->trueColor ? gdImageTrueColorPixel(img,col,row) : gdImagePalettePixel(img,col,row));

[mko]

Actually, this error is based upon the image creation in maperror.c. msWriteErrorImage() does not distinguish between PC256 and RGB. Patch enclosed. Not sure if transparency works for the truecolor part.

[mko]

distinguish between pc256 and rgb in msWriteErrorImage

[hopfgartner]

The patch has been updated to MapServer 5.6.6 and tested on CentOS 5.6.

[hopfgartner]

Updated file for MS 5.6.6

[sdlime]

Applied in r11755. Could someone test please? I guessing this does not affect 6.0+ so I'm marking as fixed.

Steve

[hopfgartner]

Works for me.