[GRASS5] [bug #976] (grass) v.transform would not read that header of files

[rgrmill at rt66.com]

Radim,

> The code for transformation of attributes was not changed, and i 
cannot get
> the segfault - i tested warious combinations of non existing files 
> /directories and incorect records in dig_att. So i don't know.
> 
> You could maybe 'strace v.transform' so that we know if dig_att was 
opened.

I ran it through gdb.  The error occurs when opening the new dig_att 
file.  It is caused because the pointer to the mapset (Trans.mapset) had 
an initial value of 0X64.  The code in G__file_name assumes that the 
mapset value that it is passed is either 0 or that it points to an 
accessible location; 0X64 isn't an accessible location.

I can get around the problem by initializing with Trans.mapset=NULL.

The mapset name for the current dig_att file (Current.mapset) was also 
uninitialized, but it had an initial value of 0x0, so it passed the test 
used in G__file_name without tripping a seg fault.

The program was compiled with gcc 2.95.2 and (I think) libc6.2 on a SuSE 
7.1 Linux system.  I invoked the command with:

v.transform i=plume_area o=tr_plume_area p=592newpoints


Roger Miller