[GRASS-dev] [GRASS GIS] #719: v.edit tool=break: breaking more then 6 coords and producing of an unexpected line

[GRASS GIS]

#719: v.edit tool=break:  breaking more then 6 coords and producing of an
unexpected line
--------------------------+-------------------------------
  Reporter:  achim        |      Owner:  martinl
      Type:  defect       |     Status:  reopened
  Priority:  major        |  Milestone:  7.0.3
 Component:  Vector       |    Version:  7.0.2
Resolution:               |   Keywords:  v.edit tool=break
       CPU:  Unspecified  |   Platform:  Linux
--------------------------+-------------------------------

Comment (by GG12345):

 Hello and Happy Christmas to all !
 Sorry for the delay, was doing additional testing.

 This bug seems to like Xmas time...
 I reopened the ticket because I still have the same artifacts on 7.0.2.

 Below is a simple way to reproduce the bug :

 In a location based on EPSG:27572

 {{{
 v.in.ogr --overwrite -o input=/.../test_break_lines2.shp output=ptnet
 v.edit --verbose --overwrite map=ptnet layer=1 type=line tool=break
 coords=531934.28,1851818.17,531949.15,1851831.79 threshold=0.01
 v.out.ogr --overwrite -cs input=ptnet olayer=ptnet format=ESRI_Shapefile
 type=line output=/.../test dsco="SHPT=ARC"
 }}}
 Data is attached.

 v.edit behaves differently depending on the precision of breaking
 coordinates. For the following examples I used only one point to break the
 lines.
 - With 8 decimals (531934.283798572,1851818.16932773) it selects the
 features but does not brake them. Debug=3 shows that spdist value of
 Vect_line_distance is 0 which is wrong. I wasn't able to track the bug
 further.
 - With 2 decimals (531934.28,1851818.17) it selects 2 features but breaks
 2 which is wrong
 - With 3 decimals (531934.283,1851818.169) it selects 3 features and
 breaks 2 which are both wrong

 Is it the same bug as for 6.5 ? Any solution ?

 Thanks for the help !
 Cev.


 g.version shows :
 {{{
 GRASS 7.0.2 (2015)
 PROJ.4: 4.8.0
 GDAL/OGR: 1.10.1
 GEOS: 3.4.2
 SQLite: 3.8.7.1
 }}}
 g.proj shows :
 {{{
 -PROJ_INFO-------------------------------------------------
 name       : Lambert Conformal Conic
 proj       : lcc
 ellps      : clark80IGN
 lat_1      : 46.8
 lat_0      : 46.8
 lon_0      : 0
 k_0        : 0.99987742
 x_0        : 600000
 y_0        : 2200000
 towgs84    : -168,-60,320,0,0,0,0
 pm         : paris
 no_defs    : defined
 -PROJ_EPSG-------------------------------------------------
 epsg       : 27572
 -PROJ_UNITS------------------------------------------------
 unit       : meter
 units      : meters
 meters     : 1
 }}}
 g.region shows :
 {{{
 projection: 99 (Lambert Conformal Conic)
 zone:       0
 datum:      towgs84=-168,-60,320,0,0,0,0
 ellipsoid:  clark80IGN
 north:      1
 south:      0
 west:       0
 east:       1
 nsres:      1
 ewres:      1
 rows:       1
 cols:       1
 cells:      1
 }}}

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Ticket URL: <https://trac.osgeo.org/grass/ticket/719#comment:18>
GRASS GIS <https://grass.osgeo.org>