[mapserver-users] Topology error prevents rendering

[Stephen Woodbridge]

On 2/14/2012 3:37 AM, Rahkonen Jukka wrote:
> Hi,
> OpenStreetMap data tend to contain topology errors and Mapserver sends
> an empty map when it finds an error on one layer of a multi-layer map.
> Cases are like this:
> msOGRFileNextShape(): OGR error. TopologyException: side location
> conflict at 1.48639e+006 6.89386e+006
> [Tue Feb 14 09:41:37 2012].113000 msDrawMap(): Image handling error.
> Failed to draw layer named 'landuse_layer1'.
> Topology errors would be best to correct in the data but I wonder if
> Mapserver could be somehow more robust and just skip the faulty feature
> or that certain layer instead of giving in totally. Sometimes it would
> be better to get an incomplete map than no map at all.
> -Jukka Rahkonen-

Jukka,

This is actually an issue in OGR. If you put the same data in a 
shapefile, mapserver will serve it with no problem but when you go 
through the OGR interface, OGR is throwing the error. It might be 
possible to make the OGR driver in mapserver more forgiving, but that 
probably depends on whether or not the OGR error is recoverable and it 
can continue.

I would write a ticket for this issue and assign it to the OGR driver 
module.

-Steve W