v.buffer: strange result for lines

[martinl]

Sample data attached: attachment:silnice.txt​

Buffer 1000m - OK (attachment:vector_1000.png)

v.buffer input=silnice output=silnice1000 distance=1000

Buffer 100m (using GEOS) - surprisingly wrong (attachment:vector_100_geos.png)

v.buffer input=silnice output=silnice100 distance=100

Buffer 100m (using GRASS) - wrong - not surprisingly (attachment:vector_100_grass.png)

export GRASS_VECTOR_BUFFER=1
v.buffer input=silnice output=silnice100 distance=100

[martinl]

sample data

[martinl]

Buffer 1000m

[martinl]

Buffer 100m (GRASS)

[martinl]

Buffer 100m (GEOS)