[GRASS-dev] v.extracy fails for type=boundary

[Nikos Alexandris]

Dears,

I get something unexpected using type=boundary with `v.external`:

```
v.extract input=european_grid_10k_boundaries out=test type=boundary --v --o
Using native format
Extracting features...
 100%
Building topology for vector map <test at PERMANENT>...
Registering primitives...
0 primitives registered
0 vertices registered
Topology was built
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
Writing attributes...
```

I tried this in both 7.4 and trunk.

The map does have boundaries,
```
v.info -t european_grid_10k_boundaries
nodes=253
points=0
lines=0
boundaries=422
centroids=177
areas=177
islands=8
primitives=599
map3d=0
```

I can draw the boundaries on-screen using `d.vect type=boundary`.

The vector map is small, so I have attached it here-in, in case someone
can have a quick look.

Thank you, Nikos
-------------- next part --------------
A non-text attachment was scrubbed...
Name: european_grid_10k_boundaries.grasspack
Type: application/octet-stream
Size: 29681 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/grass-dev/attachments/20180504/362fde93/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 228 bytes
Desc: not available
URL: <http://lists.osgeo.org/pipermail/grass-dev/attachments/20180504/362fde93/attachment-0001.sig>