v4.8.0 ncgen not handling path names correctly on Windows

[openSourcerer9000]

I'll keep this short since the symptom is pretty simple. Basically ncgen -o output option is taking an absolute path argument and converting it into one long file name. This is a regression from version 4.7. This unexpected behavior only happens on Windows, on Linux it still generates the file in the correct location.

• How to reproduce:
  On windows:

Using version 4.7:
$ ncgen -o C:\Users\you\Desktop\temp\fourpointseven.nc C:\Users\you\Desktop\temp\test_cdl.cdl
<generates the .nc to the path C:\Users\you\Desktop\temp\fourpointseven.nc>

Using version 4.8.0:
$ ncgen -o C:\Users\you\Desktop\temp\fourpointeight.nc C:\Users\you\Desktop\temp\test_cdl.cdl
<generates the .nc to a file named UsersyouDesktoptempfourpointeight.nc in wherever CD is>

Any .cdl will work for the test, I'm using this one:

netcdf timeseries {
dimensions:
    time = 2;
variables:
    double time(time);
        time:standard_name = "time";
        time:long_name = "Time";
        time:axis = "T";
        time:units = "seconds since 1970-01-01T00:00:00Z";
    float lat;
        lat:standard_name = "latitude";
        lat:units = "degrees_north";
        lat:axis = "Y";
        lat:long_name = "Latitude";
    float lon;
        lon:standard_name = "longitude";
        lon:units = "degrees_east";
        lon:axis = "X";
        lon:long_name = "Longitude";
    float z;
        z:standard_name = "depth";
        z:positive = "down";
        z:units = "m";
        z:long_name = "Depth below surface";

    float temperature(time);
        temperature:standard_name = "sea_water_temperature";
        temperature:units = "deg_C";
        temperature:long_name = "Seawater Temperature";
        temperature:coordinates = "time lat lon z";

}

• environmental information (i.e. Operating System, compiler info, java version, python version, etc.)
  I am using libnetcdf with python, I've tested this with python 3.7,3.8,3.9.

[DennisHeimbigner]

I am curious; how does python come in to play here. Are you calling ncgen using python?
In any case, I will investigate.

[openSourcerer9000]

I wouldn't think it affects anything, that's just my exposure to this library, from a python background. It should be reproducible from the CLI only.

[DennisHeimbigner]

I found the problem. There was an issue with certain shell programs (bash notably).
For certain platforms and when given a url that had an escaped '#' character (e.g. #)
bash would not remove the backslash. So I had to add a hack for this. Unfortunately
I overdid it and it removed all '' characters. This is ok for non-windows platforms,
but obviously fails for windows.
I am preparing a fix now, but if you need it in a hurry, the general solution is this:

1. In netcdf-c/ncgen/main.c replace all occurrences of NC_backslashUnescape(XXX) with strdup(XXX).
2. Similarly for netcdf-c/ncdump/ncdump.c
3. Similarly for netcdf-c/ncdump/nccopy.c

[DennisHeimbigner]

Fixed (I hope) by PR #1989