Error: *** glibc detected *** double free or corruption (!prev)

[Umberto Nicoletti]

Dominik,
this is getting very hard to do if you don't know a bit about programming.

If you want to try anyway, run shp2img under gdb with the following command:

#gdb /path/to/shp2img
>run -m pathtothefile.map -o /tmp/map.png

When it segfaults issue this command in the gdb shell:

#backtrace

and post its output here.

Umberto

On 7/9/07, Dominik Schmid <dominik.schmid at ilu.ch> wrote:
> I have recompiled 4.0.1 with debug enabled. I then replaced the existing
> shp2img and mapserv.cgi with the newly compiled binaries. Next I ran
> shp2img with '-all_debug 9' and 'layer_debug 9' for the offending layer
> (data from zp_au). Since I have no idea what possible debug levels there
> are or what numbers can be set I have chosen to use a value of 9. Here's
> the output of shp2img:
>
> [Mon Jul  9 12:18:03 2007].176107 msPOSTGISLayerOpen called
> datastatement: the_geom from zp_au
> [Mon Jul  9 12:18:03 2007].185943 msPOSTGISLayerFreeItemInfo called
> [Mon Jul  9 12:18:03 2007].186621 msPOSTGISLayerInitItemInfo called
> [Mon Jul  9 12:18:03 2007].189609 msPOSTGISLayerWhichShapes called
> [Mon Jul  9 12:18:03 2007].190383 msPOSTGISLayerParseData: unique column
> = OID, srid='', geom_column_name = the_geom, table_name=zp_au
> [Mon Jul  9 12:18:03 2007].192024 query_string_0_6:DECLARE mycursor
> BINARY CURSOR FOR SELECT
> grundnut::text,asbinary(force_collection(force_2d(the_geom)),'NDR'),OID::text
> from zp_au WHERE the_geom && setSRID('BOX3D(760644.999999999
> 249797.999999997,769195.000000001 261197.000000002)'::BOX3D,
> find_srid('','zp_au','the_geom') )
> *** glibc detected *** double free or corruption (!prev): 0x0956da40 ***
>
>
> Since this debug information doesn't help me pinpoint the problem I have
> to ask back here at the list if this tells anyone here anything.
>
> Any help is appreciated.
>
> Dominik
>
>
> Umberto Nicoletti wrote:
> > If you still have the 4.0.1 sources recompile them with enable debug
> > and run shp2img under gdb. This at least will tell you where the
> > double free is happening and then you might even be able to fix it.
> >
> > Umberto
> >
> > On 7/4/07, Dominik Schmid <dominik.schmid at ilu.ch> wrote:
> >> Hi
> >>
> >> I have run into this persistent problem and I have already spent hours
> >> upon
> >> hours without any result whatsoever. First of all my setup:
> >>
> >> - Centos 4.4
> >> - apache 2.0.52
> >> - php 5.1.6
> >> - postgresql 8.1.8
> >> - mapserver 4.0.1 (I know, I should update mapserver, but having to
> >> rebuild
> >> all the legends in our system and possibly avoid some other side effects
> >> would be a major headache and have so far kept me from doing this)
> >> - gdal 1.4.0
> >> - postgis 1.2.1
> >> - geos 2.2.3
> >> - proj 4.5.0
> >> - glibc 2.3.4-2.25
> >>
> >> The error in the httpd error_log reads as stated in the subject.
> >>
> >> I have added some multipolygon data that I had previously obtained by
> >> converting it from a shape file using shp2pgsql.
> >>
> >> The odd part about this error is, that I use the same syntax in the
> >> map file
> >> as for a working multipolygon layer that I had imported using older
> >> versions
> >> of postgis etc. and the older data works just fine.
> >> I have reimported said working data from the original shape file and
> >> compared it to the existing data in the working table. the_geom and other
> >> relevant stuff is identical. And still the newly imported data
> >> produces this
> >> error.
> >>
> >> I have checked projection, db access privs and just about everything else
> >> that crossed my mind as playing a part to no avail.
> >>
> >> So, is this problem a known issue? What else could I try/look into?
> >> Any advice?
> >>
> >> Thanks
> >> Dominik
> >>
> >
>
>
> --
> Dominik Schmid
> Dipl. Umweltnaturwissenschafter ETH
>
> ilu AG
> Zentralstrasse 2a
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>
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>
> mailto:dominik.schmid at ilu.ch
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>