[geos-devel] Buffering of invalid polygon seems to produce a less useable result

[Sandro Santilli]

On Mon, Sep 29, 2014 at 07:05:28PM +0000, Casper Børgesen (CABO) wrote:

> Are there any methods to better ensure validity of geometries resulting
> from the various geometric functions?

By contract, if the inputs are invalid, the output are not guaranteed
not only to be valid but also to be computable.

A valid input should always result in a valid output, or it would be a bug.

Turning an invalid geometry to a valid one can be tricky, you may want
to look at the ST_MakeValid funcition in PostGIS to see how it is
implemented.

--strk; 

 ()  ASCII ribbon campaign  --  Keep it simple !
 /\  http://strk.keybit.net/rants/ascii_mails.txt