[GRASS-dev] G7: parser - suppressing label in scripts

[Glynn Clements]

Markus Neteler wrote:

> we have a problem with the introduction of labels:
> http://trac.osgeo.org/grass/changeset/39886/grass/trunk/lib/gis/parser_standard_options.c

Actually, the problem only arose with the addition of standard options
in r47421.

> It would be good to be able to suppress "label" with the a reserved word
> like "None" or "NULL":
> 
> #%option G_OPT_V_INPUTS
> #% key: vector
> #% label: NULL
> #% description: Name of input vector map(s) used by GRASS script
> #% required: no
> #%end

> Any suggestions how to implement this suppressing "label" in the parser?

In parse.c, I suggest adding e.g.:

	static char *xstrdup(const char *arg) {
	    return (strcmp(arg, "{NULL}") == 0)
	        ? NULL 
	        : strdup(arg);
	}

and replacing all references to strdup() with xstrdup(). Also,
translate() will need a test for NULL pointers.