[mapserver-users] Expression segmentation fault
thomas bonfort
thomas.bonfort at gmail.com
Fri Sep 6 07:40:09 PDT 2013
Frank,
I'm able to reproduce this with a geometrycollection empty. What's
strange is I was obliged to force postgis to return the feature, as
the bounding box where clause was filtering it out and it was
therefore never returned to mapserver.
I'll come up with a patch soon, would you mind opening an issue for this please?
thanks,
thomas
On Fri, Sep 6, 2013 at 2:20 PM, Frank Broniewski <brfr at metrico.lu> wrote:
> Ok, so I did a little bit of geometry testing. Don't know why that should
> cause an expression crash, but well ...
>
> here's the query I ran on planet_osm_line and planet_osm_polygon in PostGIS:
>
> select
>
> osm_id, boundary, admin_level, tags,
> st_isvalid(way) as isvalid,
> st_isvalidreason(way) as reason,
> st_isclosed(way) as isclosed,
> st_isempty(way) as isempty,
> st_geometrytype(way) as geometrytype,
> st_length(way) as length,
> st_perimeter(way) as perimeter,
> st_numgeometries(way) as numgeometries,
> st_numinteriorrings(way) as numinteriorrings,
> st_astext(way) as wkt
>
> from planet_osm_polygon
>
> where way && st_transform(st_setsrid('BOX3D(0 0, 150000 200000)'::box3d,
> 2169), 3857)
> and tags ?& ARRAY['boundary', 'admin_level']
>
> order by geometrytype, admin_level, name
>
> There's one record that differs from the rest in the planet_osm_polygon
> table. I've pasted the result below. It has a geometrytype of
> GEOMETRYCOLLECTION and is empty, so that may cause a crash ...
>
> 229382895;"administrative";"8";""area"=>"yes", "name"=>"RW 10",
> "boundary"=>"administrative", "admin_level"=>"8", "flood_prone"=>"no",
> "is_in:hamlet"=>"MENTENG DALAM", "is_in:district"=>"Jakarta Selatan",
> "is_in:province"=>"DKI Jakarta", "is_in:subdistrict"=>"TEBET"";t;"Valid
> Geometry";;t;"ST_GeometryCollection";0;0;0;;"GEOMETRYCOLLECTION EMPTY"
>
>
> The attributes confirm, that this record could be a remain of
> http://www.openstreetmap.org/browse/way/229382895 , but I really wonder why
> it gets caught in the bbox which should center around Luxembourg with parts
> of the surrounding countries. But when the geometry is a black hole you
> never know :-)
>
>
>
> Am 2013-09-05 16:30, schrieb Stephen Woodbridge:
>
>> Hi,
>>
>> This is a great idea. Regardless we should try to identify the case that
>> is causing the crash and trap that. Mapserver should never crash as a
>> general rule so finding the specific case is important so Thomas can
>> reproduce it.
>>
>> If you have (or can load) the data in a database table, then it should
>> be fairly easy to do a manual binary search to find the offending object
>> by adding " where gid between <lower> and <upper>" to your query and
>> adjusting the value of lower and upper to narrow the search to the
>> problem object.
>>
>> Thanks,
>> -Steve W
>>
>> On 9/5/2013 10:11 AM, Rahkonen Jukka wrote:
>>>
>>> Hi,
>>>
>>> Osm2pgsql can create invalid polygons with self-intersections and/or
>>> three-vertex A-B-A rings. It might be good to run MakeValid or simply
>>> find possibly invalid features with IsValid and delete them and then
>>> see if Mapserver gets happy. Actually, run IsValid and save the
>>> faulty geometries somewhere before correcting or deleting them. It
>>> would be nice to catch them if they happen to be the reason for the
>>> crash.
>>>
>>> -Jukka Rahkonen-
>>>
>>> Frank Broniewski wrote:
>>>>
>>>>
>>>> Ok, this is weird. It is, as I know now, data source related. I was
>>>> poking in the layer configuration to find out why the core dump
>>>> happens. Reinstalling didn't solve the issue, btw.
>>>>
>>>> So first I converted the data to shapefile with ogr2ogr (as always
>>>> very handy!) and changed the layer accordingly. And no core dump
>>>> happened! Then I tried several versions of the data and filter
>>>> statements without success. Since this is a osm2pgsql database I
>>>> swapped finally the table from planet_osm_polygon to
>>>> planet_osm_line (same table schema apart from the geometry) - and
>>>> voilà - no core dump.
>>>>
>>>> So I can relate the problem to the planet_osm_polygon table - but
>>>> I'm not sure what difference actually is responsible for the crash
>>>> ...
>>>>
>>>> The most apparent difference is of course the geometry type:
>>>> planet_osm_line is linestring, planet_osm_polygon is geometry ...
>>>>
>>>> I will investigate the attributes further tomorrow, but now I need
>>>> to earn some money. It's always the deadlines ...
>>>>
>>>>
>>>> Frank
>>>>
>>>>
>>>> Am 2013-09-05 09:47, schrieb thomas bonfort:
>>>>>
>>>>> Frank, This is such a simple use-case that I doubt it's a bug in
>>>>> the code per-se. Can you make sure that you are using a clean
>>>>> build (make clean && make && make install) as I suspect this
>>>>> could be happening due to a compilation problem (as a rule of
>>>>> thumb, with mapserver <6.4, always run make clean after
>>>>> re-running configure)
>>>>>
>>>>> -- thomas
>>>>>
>>>>>
>>>>> On Wed, Sep 4, 2013 at 2:39 PM, Frank Broniewski
>>>>> <brfr at metrico.lu> wrote:
>>>>>>
>>>>>> Am 2013-09-04 14:33, schrieb thomas bonfort:
>>>>>>
>>>>>>> Frank, please supply a backtrace of the crash (`bt` in gdb
>>>>>>> once it has halted at the segfault)
>>>>>>>
>>>>>>> -- thomas
>>>>>>>
>>>>>>> On Wed, Sep 4, 2013 at 2:25 PM, Frank Broniewski
>>>>>>> <brfr at metrico.lu>
>>>>
>>>> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> I just updated my mapserver installation to the latest
>>>>>>>> version (6.2.1). I'm running FreeBSD 9.1 and I'm getting a
>>>>>>>> segmentation fault related to expression usage in my
>>>>>>>> mapfile. I've already compiled mapserver with debug symbols
>>>>>>>> and I loaded the core file into gdb:
>>>>>>>>
>>>>>>>>> gdb /usr/local/www/apache22/cgi-bin/mapserv mapserv.core
>>>>>>>>
>>>>>>>>
>>>>>>>> <snip> Reading symbols from /lib/libc.so.7...done. Loaded
>>>>>>>> symbols for /lib/libc.so.7 Reading symbols from
>>>>>>>> /usr/local/lib/libintl.so.9...done. Loaded symbols for
>>>>>>>> /usr/local/lib/libintl.so.9 Reading symbols from
>>>>>>>> /usr/lib/libsupc++.so.1...done. Loaded symbols for
>>>>>>>> /usr/lib/libsupc++.so.1 Reading symbols from
>>>>>>>> /libexec/ld-elf.so.1...done. Loaded symbols for
>>>>>>>> /libexec/ld-elf.so.1 #0 0x00000008008e2520 in yylex
>>>>>>>> (lvalp=0x7fffffffd250, p=0x7fffffffd3b0) at
>>>>>>>> mapparser.y:649 649 mapparser.y: No such file or
>>>>>>>> directory. in mapparser.y [New Thread 809007400 (LWP
>>>>>>>> 101134/mapserv)]
>>>>>>>>
>>>>>>>> So apparently there seems to be a file missing!? Looking at
>>>>>>>> the source code (git), line 649 is a blank line, so I'm not
>>>>>>>> sure what's missing exactly. I've got yacc, bison and flex
>>>>>>>> installed. For testing purposes I'm using the mapserver cgi
>>>>>>>> on the command line:
>>>>>>>>
>>>>>>>> /usr/local/www/apache22/cgi-bin/mapserv -nh
>>>>>>>>
>>>>>>>>
>>>> "QUERY_STRING=map=/data/web/mapserver/cnra/cnra.map&mode=map&laye
>>>> r=boundaries"
>>>>>>>>
>>>>>>>>
>>>>>>>> The boundaries layer:
>>>>>>>>
>>>>>>>> Layer
>>>>>>>>
>>>>>>>> # Classitem "level" Connection "host=10.0.0.2 dbname=osm
>>>>>>>> user=user
>>>>
>>>> password=guessme"
>>>>>>>>
>>>>>>>> Connectiontype Postgis Data "geom FROM (SELECT osm_id, way
>>>>>>>> AS geom, name, admin_level
>>>>
>>>> AS
>>>>>>>>
>>>>>>>> level, tags FROM planet_osm_polygon) AS foo USING UNIQUE
>>>>>>>> osm_id USING
>>>>
>>>> SRID=3857"
>>>>>>>>
>>>>>>>> Filter "tags ?& ARRAY['boundary', 'admin_level']" Name
>>>>>>>> "boundaries" Processing "CLOSE_CONNECTION=DEFER" Status on
>>>>>>>> Type line Units meters
>>>>>>>>
>>>>>>>> Metadata "ows_title" "Boundary Map" "ows_abstract"
>>>>>>>> "Boundary map - data from OpenStreetMap, ODbl licensed"
>>>>>>>> End
>>>>>>>>
>>>>>>>> Projection "init=epsg:3857" End
>>>>>>>>
>>>>>>>> Class
>>>>>>>>
>>>>>>>> Expression ("[level]" = "6") # Expression "6" Name
>>>>>>>> "communes"
>>>>>>>>
>>>>>>>> Style Color 10 10 10 Opacity 50 Width 2 End
>>>>>>>>
>>>>>>>> End End
>>>>>>>>
>>>>>>>>
>>>>>>>> The classitem / simple expression (Expression "6") works
>>>>>>>> with the mapserver cgi, but python mapscript throws an
>>>>>>>> error: _mapscript.MapServerError: msEvalExpression():
>>>>>>>> General error message. Invalid item index.
>>>>>>>>
>>>>>>>> I've read the mapserver expressions documentation [1] and
>>>>>>>> the note that says something about the working environment
>>>>>>>> might be linked to more than
>>>>
>>>> one
>>>>>>>>
>>>>>>>> expression library. But my operating system skills are not
>>>>>>>> high enough to turn this paragraph into something useful
>>>>>>>> for me.
>>>>>>>>
>>>>>>>> So any help is greatly appreciated.
>>>>>>>>
>>>>>>>> Frank
>>>>>>>>
>>>>>>>>
>>>>>>>> Frank BRONIEWSKI
>>>>>>>>
>>>>>>>> METRICO s.à r.l. géomètres technologies d'information
>>>>>>>> géographique rue des Romains 36 L-5433 NIEDERDONVEN
>>>>>>>>
>>>>>>>> tél.: +352 26 74 94 - 28 fax.: +352 26 74 94 99
>>>>>>>> http://www.metrico.lu
>>>>>>>> _______________________________________________
>>>>>>>> mapserver-users mailing list
>>>>>>>> mapserver-users at lists.osgeo.org
>>>>>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> Hi Thomas,
>>>>>>
>>>>>> thanks for the fast response! Here's the bt:
>>>>>>
>>>>>> (gdb) bt
>>>>>>
>>>>>> #0 0x00000008008e2520 in yylex (lvalp=0x7fffffffd250,
>>>>>> p=0x7fffffffd3b0) at mapparser.y:649 #1 0x00000008008e0146 in
>>>>>> yyparse (p=0x7fffffffd3b0) at mapparser.c:1500 #2
>>>>>> 0x00000008009239b2 in msEvalExpression (layer=0x809009000,
>>>>>> shape=0x7fffffffd4e0, expression=0x8090a0280, itemindex=-1) at
>>>>>> maputil.c:478 #3 0x0000000800923f03 in msShapeGetClass
>>>>>> (layer=0x809009000, map=0x8090bd800, shape=0x7fffffffd4e0,
>>>>>> classgroup=0x0, numclasses=1) at maputil.c:581 #4
>>>>>> 0x0000000800980ab2 in msDrawVectorLayer (map=0x8090bd800,
>>>>>> layer=0x809009000, image=0x8090a91c0) at mapdraw.c:989 #5
>>>>>> 0x00000008009800ed in msDrawLayer (map=0x8090bd800,
>>>>
>>>> layer=0x809009000,
>>>>>>
>>>>>> image=0x8090a91c0) at mapdraw.c:808 #6 0x000000080097ed18 in
>>>>>> msDrawMap (map=0x8090bd800, querymap=0)
>>>>
>>>> at
>>>>>>
>>>>>> mapdraw.c:437 #7 0x0000000800a16e6e in
>>>>>> msCGIDispatchImageRequest
>>>>
>>>> (mapserv=0x8090b2300) at
>>>>>>
>>>>>> mapservutil.c:1448 #8 0x0000000800a179c2 in
>>>>>> msCGIDispatchRequest (mapserv=0x8090b2300)
>>>>
>>>> at
>>>>>>
>>>>>> mapservutil.c:1690 #9 0x00000000004012c1 in main (argc=3,
>>>>>> argv=0x7fffffffd9f0) at mapserv.c:259 (gdb)
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> -- Frank BRONIEWSKI
>>>>>>
>>>>>> METRICO s.à r.l. géomètres technologies d'information
>>>>>> géographique rue des Romains 36 L-5433 NIEDERDONVEN
>>>>>>
>>>>>> tél.: +352 26 74 94 - 28 fax.: +352 26 74 94 99
>>>>>> http://www.metrico.lu
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> -- Frank BRONIEWSKI
>>>>
>>>> METRICO s.à r.l. géomètres technologies d'information géographique
>>>> rue des Romains 36 L-5433 NIEDERDONVEN
>>>>
>>>> tél.: +352 26 74 94 - 28 fax.: +352 26 74 94 99
>>>> http://www.metrico.lu
>>>> _______________________________________________ mapserver-users
>>>> mailing list mapserver-users at lists.osgeo.org
>>>> http://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>
>>> _______________________________________________ mapserver-users
>>> mailing list mapserver-users at lists.osgeo.org
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>>>
>>
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>
>
>
> --
> Frank BRONIEWSKI
>
> METRICO s.à r.l.
> géomètres
> technologies d'information géographique
> rue des Romains 36
> L-5433 NIEDERDONVEN
>
> tél.: +352 26 74 94 - 28
> fax.: +352 26 74 94 99
> http://www.metrico.lu
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users
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