[GRASS-dev] Re: [GRASS GIS] #565: r.colors: glibc double free or corruption with -ae

[GRASS GIS]

#565: r.colors: glibc double free or corruption with -ae
---------------------+------------------------------------------------------
  Reporter:  hamish  |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect  |      Status:  closed                   
  Priority:  minor   |   Milestone:  6.5.0                    
 Component:  Raster  |     Version:  svn-develbranch6         
Resolution:  fixed   |    Keywords:  r.colors                 
  Platform:  Linux   |         Cpu:  x86-32                   
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Changes (by hamish):

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

Comment:

 {{{
 G> r.univar -g map1
 ...
 min=-23.8941449919674
 max=1999.8932486971
 ...
 }}}
 {{{
 ...
 #7  0x0804b386 in get_fp_stats (name=0x9b72640 "map1", mapset=0x9b72030
 "user7",
     statf=0xbfd05f94, min=3.2146326349358647, max=7.601348984183665,
 geometric=0,
     geom_abs=1) at stats.c:136
 }}}

 Glynn:
 > If any of the raster values lie outside of the range specified
 > by the min/max parameters, memory corruption will occur due to
 > modifying an out-of-range array element.

 > FWIW, I have noticed a bug in get_fp_stats(...,geom_abs=1):
 > if the range is signed, values which are closer to zero than
 > both min and max will also modify an out-of-range array element.

 > I'll fix that one shortly, but it won't help if the min/max
 > parameters are bogus.

 thanks, that solved the problem. backported to 6.4.0 and devbr6.

 are the min/max values really bogus? r.univar and 'r.info -r' both give
 (-23,1999) for those values. The 'max' value seen in gdb frame # 7 (ie
 7.60) is simply the natural log of the max value in the map (1999). The
 min value in frame # 7 (3.2146) is a bit weirder. AFAICT it comes from
 ln(abs(min)+1). But hopefully that weirdness was just product of this bug.

 closing ticket, "thanks heaps"

 Hamish

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/565#comment:5>
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