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[netCDF #GAJ-689004]: Corrupted netCDF when adding dimension

I did a quick test with the current master and using HDF5 1.10.3.
It seems to work ok. I think some work was done on the handling
of coordinate variables and dimensions recently, so that  may
have inadvertently fixed the problem. You might try again with
release netcdf 4.6.3.



> Package Version: netCDF 4.6.2, HDF5 1.8.21
> Operating System: Linux
> Hardware:
> Description of problem: I find a strange error when adding a dimension to an 
> already existing netCDF file.
> 
> Using the attached "step1-generate.c" code, I generate a small netCDF file. 
> It contains just a coordinate variable inside the "data" group. So far, 
> everything is ok. This is the output from "ncdump":
> 
> netcdf output {
> group: data {
> dimensions:
> coordinate_variable = 10 ;
> variables:
> short coordinate_variable(coordinate_variable) ;
> data:
> coordinate_variable = _, _, _, _, _, _, _, _, _, _ ;
> } // group data
> }
> 
> Afterwards, I append the file and insert a new dimension and its 
> corresponding variable, using "step2-append.c".
> 
> Both programs are apparently successful, because they do not throw any error. 
> However, when I try "ncdump" I get the following error:
> 
> netcdf output {
> dimensions:
> coordinate_variable = 10 ;
> variables:
> NetCDF: Invalid dimension ID or name
> Location: file ncdump.c; line 1740
> short my_var
> [AND NO MORE LINES!]
> 
> Some comments:
> * the "coordinate_variable" was created inside the "data" group, not at root 
> level.
> * The problem seems to be directly related to the existence of a coordinate 
> variable ("variable" and "dimension" having the same name).
> * netCDF commands ("ncdump", "nccopy") do not work.
> * HDF5 commands work well (for example, "h5repack").
> * This test presented here has been implemented in C, but the same happens in 
> Python.
> 
> Therefore:
> * This issue seems to be related to netCDF and not HDF5.
> * This issue requires the existence of at least a coordinate variable.
> * When all dimensions and variables are located at root level, it works well. 
> This issue requires the coordinate variable to be in a group.
> * The behavior is erratic. When the variable ("my_var") in "step2-append.c" 
> is not added (because that code is commented out), then simply "my_dim" 
> dimension is invisible when using "ncdump".
> 
> Thank you in advance.
> 
> 

=Dennis Heimbigner
  Unidata


Ticket Details
===================
Ticket ID: GAJ-689004
Department: Support netCDF
Priority: Normal
Status: Open
===================
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