[PROJ] proj_create_crs_to_crs_from_pj fails with no error

[Even Rouault]

Eric,

nothing strikes me as obviously wrong in your code, but as it is not a self contained snippet, I 
cannot reproduce exactly

I've tried with the projinfo utility:

$ projinfo -s "+type=crs +proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs" -t 
"+type=crs +proj=geocent +units=m" -o PROJ -q

and it outputs a correct pipeline:

+proj=pipeline +step +proj=unitconvert +xy_in=deg +z_in=m +xy_out=rad +z_out=m +step 
+proj=cart +ellps=WGS84

The following also works fine:

cs2cs +proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs +to  +proj=geocent

This is with latest PROJ. It might be a bug in the version you use.

Even


> I'm upgrading old code to use modern proj routines and use WKS strings
> instead.  To handle old PROJ strings (because I don't know the correct
> WKS string), I hack in an extra "+type=crs".
> 
> When I do this, the call to proj_create succeeds, but
> proj_create_crs_to_crs_from_pj() returns NULL and proj_errno(NULL)
> returns 0. I want an error message!
> 
> Are my expectations for error reporting wrong here?
> 
> Here's the code snippet that's failing (throws "failed with no error")
> with crs_string2 =
>   "+type=crs +proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs"
> 
> <code>
>     PJptr const crs1 = proj_create (PJ_DEFAULT_CTX, crs_string2.c_str());
>     if (crs1.ptr == NULL)
>       throw std::runtime_error
>         (std::string ("proj_create (dest):")
>          + proj_errno_string (proj_errno (crs1.ptr)));
> 
>     PJptr const crs_ecef = proj_create (PJ_DEFAULT_CTX,
>                                         "+type=crs +proj=geocent +units=m");
> if (crs_ecef.ptr == NULL)
>       throw std::runtime_error
>         (std::string ("proj_create (ecef):")
>          + proj_errno_string (proj_errno (crs1.ptr)));
> 
>     PJ* proj0 = proj_create_crs_to_crs_from_pj
>       (PJ_DEFAULT_CTX, crs1.ptr, crs_ecef.ptr, NULL, NULL);
>     if (proj0 == NULL)
>       {
>         int const err_no = proj_errno (NULL);
>         char const * err_str = proj_errno_string (err_no);
>         if (err_str == NULL)
>           throw std::runtime_error
>             ("proj_create_crs_to_crs failed with no error");
>         else
>           throw std::runtime_error (std::string ("proj_crs_to_crs")
>                                     + proj_errno_string (proj_errno
> (NULL))); }
> </code>
> 
> I'd appreciate any advice!
> 
> -Eric
> _______________________________________________
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> PROJ at lists.osgeo.org
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