unnecessary SRID lookup makes coordinate transform from custom SRS to standard SRS fail

[reidpr@…]

Running the attached script crashes with django.contrib.gis.gdal.error.SRSException: Unsupported SRS.. It shouldn't, as the CoordTransform object contains complete information for the transformation.

The problem seems to be that the SRID of point b is looked up before the transformation, and this lookup fails (as is expected, because it's a custom SRS). But the lookup is not necessary, because the SRID of point b is ignored during the transformation (which can be demonstrated by substituting a bogus SRID on b before the transformation -- the results are still correct).

This is Django version 1.4.1 on:

• Fedora 14 with custom-compiled GDAL 1.9.2, GEOS 3.3.5, and PROJ4 4.8.0
• Debian Wheezy with GDAL 1.9.0, GEOS 3.3.3, and PROJ4 4.7.0 that came with the OS.

[reidpr@…]

script to demonstrate bug

[Claude Paroz]

Transform should work with custom srid

[Claude Paroz]

As the crash was happening during the build of the ogr geometry equivalent, I'd rather fix the issue at that level, and default to a "naive" ogr geometry when a SRSException occurred.

[Claude Paroz <claude@…>]

In 360217fc87db82575c8b07704143ced07c2a234c:

Fixed #19171 -- Allowed coordinate transforms with custom SRIDs

Thanks reidpr at lanl.gov for the report.