[postgis-devel] segfault fix and spatial_ref_sys

[strk at refractions.net]

I've just fixed a bug in the transform_geom function
segfaulting on proj4 error.

proj4 errors should not occur in everyday usage,
anyway it seems we have a problem with spatial_ref_sys
records triggering them.

The problem seems related to the lack of +proj parameter.

The following query would segfault or (if you either applied
the attached patch or are lucky) report an error:

 SELECT transform('SRID=4326;POINT(0 0)', srid)
 FROM spatial_ref_sys WHERE proj4text !~ 'proj';

This is the error (for srid=2046..2055):

 couldn't parse proj4 output string:
 '+ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs ':
 projection not named

This is a list of the 29 corrupted entries, for reference:

 srid  |                       proj4text
-------+--------------------------------------------------------
  2046 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2047 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2048 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2049 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2050 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2051 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2052 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2053 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2054 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
  2055 | +ellps=WGS84 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
 22275 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22277 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22279 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22281 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22283 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22285 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22287 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22289 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22291 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22293 | +a=6378249.145 +b=6356514.966398753 +units=m +no_defs
 22300 | +a=6378249.2 +b=6356515 +pm=paris +units=km +no_defs
 29371 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29373 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29375 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29377 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29379 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29381 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29383 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs
 29385 | +ellps=bess_nam +to_meter=1.0000135965 +no_defs


--strk;
-------------- next part --------------
Index: lwgeom/lwgeom_transform.c
===================================================================
RCS file: /home/cvs/postgis/postgis/lwgeom/lwgeom_transform.c,v
retrieving revision 1.19
retrieving revision 1.21
diff -U2 -r1.19 -r1.21
--- lwgeom/lwgeom_transform.c	5 Apr 2005 10:18:04 -0000	1.19
+++ lwgeom/lwgeom_transform.c	10 Aug 2005 23:16:26 -0000	1.21
@@ -295,5 +295,5 @@
 	if ( (input_pj == NULL) || pj_errno)
 	{
-		//pfree(input_proj4);
+		//pfree(input_proj4); // we need this for error reporting
 		pfree(output_proj4);
 		pfree(geom);
@@ -306,6 +306,5 @@
 	if ((output_pj == NULL)|| pj_errno)
 	{
-		pfree(input_proj4);
-		//pfree(output_proj4);
+		//pfree(output_proj4); // we need this for error reporting
 		pj_free(input_pj);
 		pfree(geom);