[postgis-devel] Unknown SRID <= 0 status report
strk at keybit.net
Mon Oct 10 00:58:05 PDT 2011
This mail to summarize the current state of code after
taking SRID <= 0 as unknown.
Serializer and deserializer have been changed to clamp
the SRID so to fall in the valid range: 1..999999.
Such clamping will return an ERROR if a SRID > 999999
is encountered (this was already the case before the change),
and it will return a NOTICE if a SRID < 1 is passed which is
not the _official_ SRID_UNKNOWN value. Here's an example:
=# select st_srid(st_setsrid('POINT(0 0)'::geometry, -1));
NOTICE: SRID value -1 converted to the officially unknown SRID value 0
Having the NOTICE will help figuring out how many occurrences of
explicit "unknown" SRID values are in use out there. Our own testsuite
had a few such occurrences, fixed by omitting the SRID parameter when
possible or hushing the NOTICE otherwise. Here's a list of such fixes:
Using invalid SRID values at the LWGEOM level is still possible, except
when costructing objects via WKB/WKT parsing, which does the clamping.
() Free GIS & Flash consultant/developer
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