[mapserver-users] [SOLVED] mapserver 5.0.2 segv using AGG

[Stephen Woodbridge]

Arghhh! This bug is caused by the fact that my output format requests:

     FORMATOPTION "PALETTE=/u/data/maps/palette-google-agg.txt"

and the file does not exist. I ran into this earlier and have already 
written a bug on it. Sorry the SEGV is non-intuitive to the cause and I 
guess I'm slow on the up take :(

Back you your regularly scheduled programing. :)

-Steve W

Stephen Woodbridge wrote:
> Moving this to the dev list ...
> 
> As a follow up to this it is reproducible on the current nightly tarball 
> also.
> 
> So in mapgd.c lines 3595+ are:
> 
>         gdPImg = 
> gdImageCreatePaletteFromTrueColor(img,dither,colorsWanted);
>         /* It seems there is a bug in gd 2.0.33 and earlier that leaves the
>          colors open[] flag set to one. */
>         for( i = 0; i < gdPImg->colorsTotal; i++ )
>             gdPImg->open[i] = 0;
>         gdImagePngCtx( gdPImg, ctx );
>         gdImageDestroy( gdPImg );
> 
> It looks like the call to gdImageCreatePaletteFromTrueColor() is 
> returning NULL and mapserver is not checking and dealing with this 
> condition and passing gdPImg as a NULL pointer to gdImagePngCtx( gdPImg, 
> ctx ); which is causing a SEGV when it is accessed.
> 
> Running with packages on Debian Etch:
> 
> libgd2-noxpm/stable uptodate 2.0.33-5.2
> libgd2-noxpm-dev/stable uptodate 2.0.33-5.2
> 
> I also ran into this same problem in brief experience with Fedora 8.
> 
> -Steve W
> 
> 
> Stephen Woodbridge wrote:
>> Hi all,
>>
>> Is this a known problem? I did could not find a ticket for it. I'm 
>> trying the nightly build next.
>>
>> -Steve
>>
>> woodbri at maps:/u/woodbri/work/mapserver-5.0.2$ gdb mapserv
>> GNU gdb 6.4.90-debian
>> Copyright (C) 2006 Free Software Foundation, Inc.
>> GDB is free software, covered by the GNU General Public License, and 
>> you are
>> welcome to change it and/or distribute copies of it under certain 
>> conditions.
>> Type "show copying" to see the conditions.
>> There is absolutely no warranty for GDB.  Type "show warranty" for 
>> details.
>> This GDB was configured as "x86_64-linux-gnu"...Using host 
>> libthread_db library "/lib/libthread_db.so.1".
>>
>> (gdb) run 
>> QUERY_STRING='map=%2Fu%2Fdata%2Fmaps%2Fgoogle-agg.map&layers=all&map_imagetype=agg%2Fpng24&mode=map&mapext=-88.20558679540737+41.41346751789421+-87.09441320459264+42.28653248210579&imgext=-88.20558679540737+41.41346751789421+-87.09441320459264+42.28653248210579&map_size=700+550&imgx=350&imgy=275&imgxy=700+550' 
>>  > a
>> Starting program: /u/woodbri/work/mapserver-5.0.2/mapserv 
>> QUERY_STRING='map=%2Fu%2Fdata%2Fmaps%2Fgoogle-agg.map&layers=all&map_imagetype=agg%2Fpng24&mode=map&mapext=-88.20558679540737+41.41346751789421+-87.09441320459264+42.28653248210579&imgext=-88.20558679540737+41.41346751789421+-87.09441320459264+42.28653248210579&map_size=700+550&imgx=350&imgy=275&imgxy=700+550' 
>>  > a
>> [Thread debugging using libthread_db enabled]
>> [New Thread 47982973225104 (LWP 20007)]
>> warning: Lowest section in /usr/lib/libicudata.so.36 is .hash at 
>> 0000000000000120
>>
>> Program received signal SIGSEGV, Segmentation fault.
>> [Switching to Thread 47982973225104 (LWP 20007)]
>> 0x00002ba3e360e733 in gdImagePngCtxEx () from /usr/lib/libgd.so.2
>> (gdb) where
>> #0  0x00002ba3e360e733 in gdImagePngCtxEx () from /usr/lib/libgd.so.2
>> #1  0x0000000000453bb3 in msSaveImageGDCtx (img=0x738040, ctx=0x6c1a90,
>>     format=0x6247a0) at mapgd.c:3602
>> #2  0x0000000000453d3e in msSaveImageGD (img=0x738040,
>>     filename=<value optimized out>, format=0x6247a0) at mapgd.c:3543
>> #3  0x0000000000454886 in msSaveImageAGG (img=0x738040, filename=0x0,
>>     format=0x6247a0) at mapagg.cpp:2194
>> #4  0x0000000000428f5b in msSaveImage (map=0x61d560, img=0x738000,
>>     filename=0x0) at maputil.c:604
>> #5  0x000000000040e8d4 in main (argc=<value optimized out>,
>>     argv=<value optimized out>) at mapserv.c:1580
>> (gdb) q
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> 
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