[GRASS-user] working on a mounted external disk

[Moritz Lennert]

On 08/04/09 15:37, Vincent Bain wrote:
> In raster/r.proj/main.c, line 208 I wrote :
> 
>         if (strcmp(inlocation->answer, G_location()) == 0 &&
>            !indbase->answer || strcmp(indbase->answer, G_gisdbase())==
>         0))
>         	G_fatal_error(_("Input and output locations can not be the
>         same"));
>         
>             G_get_window(&outcellhd);
> 
> Then compiled and installed again, but the error remains, and what's
> more puzzling to me is that the message string is different from what I
> have in the modified file ("You have to use a different location for
> input than the current")...
> 
> What have I done wrong ?

This sounds like you modified and compiled a grass6 version, but are 
running grass7.

Apparently a fix for this issue done by Markus a long time ago in 
grass6, but this got lost, when (IIUC) r.proj.seg became r.proj in grass7.

Markus' fix was this:

-if (strcmp(inlocation->answer, G_location()) == 0)
-     G_fatal_error(_("You have to use a different location for input
- than the current"));
+ if (!indbase->answer && strcmp(inlocation->answer, G_location()) == 0) 
+     G_fatal_error(_("Input and output locations can not be the same"));

but this was never applied to r.proj.seg. His fix does not take into 
account the case where someone gives a value for dbase, but this is the 
same as the current location. Probably highly improbable, but not 
impossible, so my fix is a bit more complete...

So, to make this story short:

- You have to figure out which version of grass you are working with.
- In grass6.3+ this shouldn't be an issue, but it is in grass6.2 and 
before and again in grass7.
- The message ""You have to use a different location for input than the 
current" is in grass6.2 and before and in grass7, but was changed to 
"Input and output locations can not be the same" in grass6.3+.

I'll apply my fix (but using Markus' wording) grass7, but I'll leave 
devel6 alone as the Markus' fix should handle most cases.

Moritz