[GRASS-dev] [GRASS GIS] #2583: v.net: crash on Windows

[GRASS GIS]

#2583: v.net: crash on Windows
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  Reporter:  mlennert     |       Owner:  grass-dev@…              
      Type:  defect       |      Status:  reopened                 
  Priority:  critical     |   Milestone:  7.0.0                    
 Component:  LibVector    |     Version:  svn-releasebranch70      
Resolution:               |    Keywords:  v.net                    
  Platform:  MSWindows 8  |         Cpu:  Unspecified              
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Comment(by mmetz):

 Replying to [comment:30 mlennert]:
 > Replying to [comment:29 wenzeslaus]:
 > > The test for v.net is now at 50%. This is a little bit suspicious. The
 values changed from yesterday before the last fixes (r64644, r64656). Test
 suite for v.net was added in r64639 and the values were obtained before
 the last fixes which can mean that r64644 or r64656 changed the results.
 Which results are the right ones? Is this even expected?
 >
 > MarkusM is the only one who can tell for sure, but I would not be
 surprised that changes in topology handling induce changes in primitive
 counts.

 The difference is caused by the fix for the uninitialized values in
 `v.net`, therefore I am sure that the new result is correct. Uninitialized
 double values (here: z coordinates) can have weird effects, I noticed that
 earlier somewhere else. Unfortunately, this bug has been present in
 `v.net` since GRASS 6.4.0 or earlier.
 >
 > At least I can confirm the difference between RC2 and current
 releasebranch results.
 >
 > Another strange thing I noticed: using the -s (snap nodes to network)
 flag, I get
 >
 > "156 lines (network arcs) written to output"
 >
 > Why are the new network arcs written when nodes are snapped to the
 network ?

 Because a line is broken up into 2 lines at the point on the line closest
 to the node, thus the old line is modified and a new line is written out
 and reported as a new arc. Of course only if the point on the line closest
 to the node is not one of the line's end points.

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2583#comment:32>
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