[GRASS5] v.extract problems

[rgrmill at rt66.com]

Glynn,

I think the change you made is a good one, but I found another problem 
that might not be related.  I ran the updated code against a vector file 
with more than 10,000 categories and tried to extract subsets ranging 
from 11 to more than 8,000 categories and consistently got seg faults.  
The problem always happens at line 272 in main.c.

The problem might be related to skipped values in the category list, but 
I can't confirm that.  It's hard enough putting together a file with 
several thousand categories.  Doing it with several thousand categories 
perfectly in sequence might be a bit much to expect :)


Roger