[GRASS-dev] [GRASS GIS] #1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
-----------------------+----------------------------------------------------
Reporter: GG1234 | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Keywords: | Platform: MSWindows 7
      Cpu: x86-64 |
-----------------------+----------------------------------------------------
Hello to all,

First of all thank you all for the great work you are all collectively
doing, I'm very often impressed by the power of open GIS.

I have been struggling with a problem on Grass 6.4.3RC1 and 6.4.3RC2 with
the v.overlay.and function.
I tried to clip a line network on a single polygon, and the output is
wrong : some lines are missing, some lines are there that should not be.
The problems occur with lines that intersect with the polygon's boundary.

I tried with different sets of data, and with simple features I created
for the test in Grass. Same wrong results.

I tried to use the same data with Grass 6.4.2 on my computer and on other
computers runnig 6.4.2 and it worked on all PCs.

I tried to upgade one PC in 6.4.2 to 6.4.3 and did the same test :
v.overlay.and produced the same erroneous output.

NB : I setup Grass 6.4.3 on my PC through osgeo4w, and 6.4.2 through the
windows standalone installer. I also just tried with the 6.4.3.RC2
standalone installer and the output was also wrong.

If it wasn't for my boss, I would switch from Windosw to the Dark Side of
the Force...

Can someone else test this function in 6.4.3 ?

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875&gt;
GRASS GIS <http://grass.osgeo.org>

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
-----------------------+----------------------------------------------------
Reporter: GG1234 | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Keywords: | Platform: MSWindows 7
      Cpu: x86-64 |
-----------------------+----------------------------------------------------

Comment(by GG1234):

I don't know if it is linked but I have the attached message when I setup
Grass 6.4.3

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875#comment:1&gt;
GRASS GIS <http://grass.osgeo.org>

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
-----------------------+----------------------------------------------------
Reporter: GG1234 | Owner: grass-dev@…
     Type: defect | Status: new
Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Keywords: | Platform: MSWindows 7
      Cpu: x86-64 |
-----------------------+----------------------------------------------------

Comment(by mmetz):

Replying to [ticket:1875 GG1234]:
>
> I have been struggling with a problem on Grass 6.4.3RC1 and 6.4.3RC2
with the v.overlay.and function.
> I tried to clip a line network on a single polygon, and the output is
wrong : some lines are missing, some lines are there that should not be.
The problems occur with lines that intersect with the polygon's boundary.

Please try GRASS 6.4 r54954, it works now for me.

Markus M

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875#comment:2&gt;
GRASS GIS <http://grass.osgeo.org>

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
--------------------------+-------------------------------------------------
  Reporter: GG1234 | Owner: grass-dev@…
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Resolution: fixed | Keywords:
  Platform: MSWindows 7 | Cpu: x86-64
--------------------------+-------------------------------------------------
Changes (by GG1234):

  * status: new => closed
  * resolution: => fixed

Comment:

Great ! It works !

Thank you for the quick help and debug.
Since I'm there just a few additional questions :

- QGS project file periodically and very regularly crashes QGIS, often
when upgrading versions on my Windows OSGEO4W setup. About once every
three months, per project which is quite a lot. Is it the same on Ubuntu
or other Linux distributions ?
When I try repairing these files, it seems to me (but with little
investigation) that openlayers plugin seem to be the cause. Am I the only
one to suffer from this and if not could it be possible to make Qgis more
stable with these files, loading only valid layers and poping the usual
warning when necessary ?
- When multiple Grass are setup with OSGEO4W, how can I know which Grass
is used in the Qgis-Grass plugin and could it be possible to switch
between Grass versions ? (more a OSGEO4W question) Same question but with
a standalone Grass setup ?
- Out of curiosity, what was the cause of this bug ? Was it a side effect
of a code optimisation of the function ?
- Regarding the Avira message, to your opinion is it an Avira deffect or a
Grass deffect ? Am I the only one having this ?

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875#comment:3&gt;
GRASS GIS <http://grass.osgeo.org>

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
--------------------------+-------------------------------------------------
  Reporter: GG1234 | Owner: grass-dev@…
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Resolution: fixed | Keywords:
  Platform: MSWindows 7 | Cpu: x86-64
--------------------------+-------------------------------------------------

Comment(by GG1234):

Regarding the QGS file crash, I believe they systematically crash when
openlayers is not setup and an openlayers layer is loaded. Should I file a
new bug ?

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875#comment:4&gt;
GRASS GIS <http://grass.osgeo.org>

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
--------------------------+-------------------------------------------------
  Reporter: GG1234 | Owner: grass-dev@…
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Resolution: fixed | Keywords:
  Platform: MSWindows 7 | Cpu: x86-64
--------------------------+-------------------------------------------------

Comment(by mmetz):

Replying to [comment:3 GG1234]:
> Great ! It works !
>
> Thank you for the quick help and debug.
> Since I'm there just a few additional questions :
>
> - QGS project file periodically and very regularly crashes QGIS, often
when upgrading versions on my Windows OSGEO4W setup. About once every
three months, per project which is quite a lot. Is it the same on Ubuntu
or other Linux distributions ?
> When I try repairing these files, it seems to me (but with little
investigation) that openlayers plugin seem to be the cause. Am I the only
one to suffer from this and if not could it be possible to make Qgis more
stable with these files, loading only valid layers and poping the usual
warning when necessary ?

You will most probably get more feedback on the QGIS mailing list about
these problems.

> - When multiple Grass are setup with OSGEO4W, how can I know which Grass
is used in the Qgis-Grass plugin and could it be possible to switch
between Grass versions ? (more a OSGEO4W question) Same question but with
a standalone Grass setup ?

For Windows, this is probably hard-coded in QGIS. Better ask on the QGIS
mailing list to make sure.

> - Out of curiosity, what was the cause of this bug ? Was it a side
effect of a code optimisation of the function ?

Yes, it was a side effect of optimization. v.overlay was until recently
terribly slow and had some bugs when overlaying areas areas, I fixed it in
trunk but did not backport all fixes.

> - Regarding the Avira message, to your opinion is it an Avira deffect or
a Grass deffect ? Am I the only one having this ?

An Avira mystery. I have a Windows machine for testing, also with Avira,
and do not get this message.

Markus M

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875#comment:5&gt;
GRASS GIS <http://grass.osgeo.org>

#1875: Wrong output of v.overlay.and between lines and polygon in 6.4.3
--------------------------+-------------------------------------------------
  Reporter: GG1234 | Owner: grass-dev@…
      Type: defect | Status: closed
  Priority: normal | Milestone: 6.4.3
Component: LibVector | Version: 6.4.3 RCs
Resolution: fixed | Keywords:
  Platform: MSWindows 7 | Cpu: x86-64
--------------------------+-------------------------------------------------

Comment(by GG1234):

Ok, thanks again Markus.
Done for the Feature #7114 and the Bug #7113

Gen.

--
Ticket URL: <http://trac.osgeo.org/grass/ticket/1875#comment:6&gt;
GRASS GIS <http://grass.osgeo.org>