[GRASS5] new raster fixes

[Markus Neteler]

On Mon, Nov 12, 2001 at 12:22:10AM +0100, Markus Neteler wrote:
> Hi,
> 
> I have fixed a few things:
>  - r.thin writes NULL instead of 0 (src/raster/r.thin/cmd/io.c)
>  - r.digit writes NULL instead of zero
>    (fix applied in src/raster/r.in.poly/raster.c)
>    For the latter I am not sure how we treat 0 categories.
>    But the NULL fix was needed to avoid other problems.

I just realized that r.mfiler also outputs 0 instead
of NULL.

All r.thin, r.digit (r.in.poly), r.mfiler seem to use unusual
write routines (or not?). At least I am not very sure how
zero shall be treated. In general 0 should be supported.
Maybe my above changes switched that off for r.thin and r.digit?
r.mfiler is untouched so far.

I am clueless here,

 Markus