[GRASS-dev] r39578 v.build: open vector map in update

[Markus Metz]

Hi Martin,

I think with r39578 you want to prevent that topo, cidx and sidx is 
written for a vector not in the current mapset, right? That makes 
perfect sense. But if a vector is opened in update mode, the files coor, 
hist, dbln, and head are also modified, not so when opened in read only 
mode with Vect_open_old(). I think this update mode mainly targets the 
coor file which is the most important file of a grass vector. You can 
get a working vector after deleting and manually restoring all files but 
the coor file. This one is the most precious one so to speak, and I 
would modify the coor file only if really necessary. Therefore I would 
suggest to open vectors in v.build with Vect_open_old(), but first make 
sure that the vector is in the current mapset as is done in 
Vect__open_old() with update requested. I know this is a bit against 
current standard because it should be done by libraries only, but in 
this case I would make an exception. What do you think?

Best,

Markus