[GRASS-user] Defect v.edit tool=break with multiple coordinates

GRASS GRASS user
, ,
1

Hi all,

I presumably detected an problem/bug with v.edit and its tool “break”. I wanted to break a line at multiple coordinates. But the result is an overlay of multiple lines instead of the original line that is broken into segments. Here a small reproducible example using the NC dataset:

from grass.script import core as grass

# Copy data from PERMANENT mapset
grass.run_command("g.copy",
    overwrite=True,
    vector="railroads@PERMANENT,railroads")
grass.run_command("v.extract",
    overwrite=True,
    input="firestations@PERMANENT",
    cat="58,66,29,35,31,32",
    output="firestations")

# Connectors to find exact break points coords
grass.run_command("v.distance",
    overwrite=True,
    to="railroads",
    from_="firestations",
    output="firestations_connectors")
firestations_connectors_coors = grass.read_command("v.to.db",
    flags="p",
    map="firestations_connectors",
    option="end",
    separator="comma").splitlines()
firestations_connectors_coors = [[",".join(x.split(",")[1:3])] for x in firestations_connectors_coors[1:]]

# Break at point coords
grass.run_command("v.edit",
      tool="break",
      map="railroads",
      coords=firestations_connectors_coors,
      threshold=50,
      layer=1,
      cats="1-99999999")

My system:

GRASS version: 7.4.1
GRASS SVN revision: r72807M
Build date: 2018-06-13
Build platform: x86_64-apple-darwin17.6.0
GDAL: 2.0.0
PROJ.4: 5.1.0
GEOS: 3.6.2
SQLite: 3.19.3
Python: 2.7.15
wxPython: 4.0.0
Platform: Darwin-17.7.0-x86_64-i386-64bit

I seems that this issue has already been detected long time ago (see https://trac.osgeo.org/grass/ticket/2903). I extended the bug ticket with my experience and details using the new GRASS versions. Interestingly, all people that reported about this problem were working on MacOS?!

Can anybody else reproduce this problem? Or does someone know a solution?

Cheers,
Johannes