[Proj] Misplaced SHP obtained with PROJ 4.8.0 called from gvSIG CE

[Jorge Arevalo]

Hello,

I'm trying to fix a bug related with PROJ in gvSIG CE. This desktop
client creates its own JNI wrapper, based on PROJ sources. The
reprojection of shapefiles using grid files works with the wrapper
based on PROJ 4.5.0, but it fails if we construct the same wrapper
based on any upper version of PROJ (PROJ 4.8.0, for example).

Here, the use case that causes the problem:

- We want to reproject this shapefile from epsg:23030 to epsg:25830:
https://dl.dropboxusercontent.com/u/6599273/gis_data/EPSG23030_data.zip

- We want to use this grid file to perform the operation:
https://dl.dropboxusercontent.com/u/6599273/gis_data/sped2et.gsb

The operation done with the JNI wrapper based on PROJ 4.5.0 works
fine. But if we use PROJ 4.8.0 as base, we get a misplaced file. Here,
a screenshot. In blue, the original shapefile. In green, the shapefile
correctly reprojected (PROJ 4.5.0). In red, the misplaced shapefile
(PROJ 4.8.0)

https://dl.dropboxusercontent.com/u/6599273/errors/gvsigce/gvsigce_misplacing_reproj.png

Debugging, we found the problem is in pj_transform.c. I guess it's
related with the way we pass information to PROJ functions. I've made
a diff between both versions (pj_transform in PROJ 4.5.0 and PROJ
4.8.0), but I see several changes, and I don't know where to focus.
Any clue?

Many thanks in advance, and best regards,

-- 
Jorge Arévalo
http://geomati.co