[netcdfgroup] Fwd: Fortran API issues with uninitialized data

• To: netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: [netcdfgroup] Fwd: Fortran API issues with uninitialized data
• From: W Spector <w6ws@xxxxxxxxxxxxx>
• Date: Wed, 21 May 2014 12:31:25 -0700

Dear NetCDFers,

==26685== Thread 1:
==26685== Conditional jump or move depends on uninitialised value(s)
==26685==    at 0x72FC83E: nf_inq_dimid_ (nf_dim.f90:136)
==26685==    by 0x736B13F: __netcdf_MOD_nf90_inq_dimid (netcdf_dims.f90:21)
==26685==    by 0x6181E82: __esmfnf_mod_MOD_pio_inq_dimid (nf_mod.F90:1218)

If one looks around line 136 in nf_dim.f90, the issue is that I have
unit tests where the eventual call to nc_inq_dimid is made with a bad
ncid.  This results in a return code /= NC_NOERR.  Then, at line 136,
undefined stack trash from cdimid is used in the if test.

There are a few ways this could be fixed, including:

1.) cdimid could be initialized to something before the call to
nc_inq_dimid is made,

2.) over on the C side, nc_inq_dimid could return a reliable value for
cdimid when an error occurs,

3.) nf_inq_dimid could check for NC_NOERR before attempting to use cdimid

Other procedures in the nf_dim.f90 file have the same issue.  And of
course other files should also be checked.

Walter