[GRASS-dev] [GRASS GIS] #2438: Vect_get_line_type cannot handle line out of range

[GRASS GIS]

#2438: Vect_get_line_type cannot handle line out of range
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  Reporter:  artegion     |       Owner:  grass-dev@…              
      Type:  defect       |      Status:  reopened                 
  Priority:  normal       |   Milestone:  7.0.0                    
 Component:  LibVector    |     Version:  unspecified              
Resolution:               |    Keywords:                           
  Platform:  Unspecified  |         Cpu:  Unspecified              
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Changes (by mmetz):

  * milestone:  6.4.5 => 7.0.0


Comment:

 Replying to [comment:2 artegion]:
 > Replying to [comment:1 mmetz]:
 > > Replying to [ticket:2438 artegion]:
 > > > calling Vect_get_line_type with line out of range (i.e. line=0)
 > > > Vect_line_alive returns -1 but Vect_get_line_type ignores it (not -1
 is False just like not 1) -> access violation reading ....
 > >
 > > This is a programmer's error. 'Vect_get_line_type()' assumes that the
 programmer first tested if the provided line id is indeed valid. You did
 call 'Vect_line_alive()' first, you can only proceed if the line is alive.
 Fix your code.
 >
 > For sure calling 'Vect_get_line_type()' with a wrong line id is a
 programmer error but 'Vect_get_line_type()' already call
 'Vect_line_alive()'.
 >
 >
 > Testing  if (!Vect_line_alive(Map, line)) is wrong because
 Vect_line_alive returns[[BR]]
 >
 > 1 feature alive[[BR]]
 >
 > 0 feature is dead[[BR]]
 >
 > -1 on error[[BR]]
 >
 >
 > a small change ( if (Vect_line_alive(Map, line!=1)) may improve code
 robustness.

 The problem comes from r55582 which introduced return -1 on error for the
 Vect_*_alive functions. Unfortunately, the existing calls to
 Vect_*_alive() were not adjusted. I have restored the behaviour of the
 Vect_*_alive() functions in r62370,1, no more need to change
 Vect_get_line_type(). Note that this applies only to G7, not to G6.

 >
 >
 >

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Ticket URL: <http://trac.osgeo.org/grass/ticket/2438#comment:4>
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