[GRASS-dev] [GRASS GIS] #2764: corrupt data written to FCELL and DCELL rasters, hard to re-produce

[GRASS GIS]

#2764: corrupt data written to FCELL and DCELL rasters, hard to re-produce
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  Reporter:  dylan   |      Owner:  grass-dev@…
      Type:  defect  |     Status:  new
  Priority:  normal  |  Milestone:  7.2.3
 Component:  Raster  |    Version:  unspecified
Resolution:          |   Keywords:
       CPU:  x86-64  |   Platform:  Linux
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Comment (by mmetz):

 Replying to [comment:14 neteler]:
 > Replying to [comment:12 dylan]:
 > > Relevant [https://www.zlib.net/manual.html zlib manual page].
 >
 > For ticket completion, here the related ''grass-user'' message:
 >
 > https://lists.osgeo.org/pipermail/grass-user/2018-January/077572.html
 >
 > On Wed, Jan 3, 2018 at 8:41 PM, Dylan Beaudette wrote:
 > > Update: after applying the latest patch, I now see
 > >
 > > ERROR: Decompression failed with error -1
 > >
 > > I found the map that fails decompression. Is there any way to inspect
 > > the map in order to search for more clues as to what is wrong with it
 > > or how it might have happened?
 > >
 > >
 > > All of the maps in this project are using the default ZLIB
 > > compression, along with compressed NULL files. Looking over the zlib
 > > manual (https://www.zlib.net/manual.html), I see several references to
 > > an error code of "-1":
 > >
 > > ----------------------------
 > > #define Z_ERRNO        (-1)
 > >
 > > Z_ERRNO if there is an error writing the flushed data
 > >
 > > Z_ERRNO on a file operation error
 > >
 > > ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));

 We can't use gzerror() because libgis does not operate on a gzFile.
 Instead we could use the undocumented zError() function, now in the
 updated patch.

 You will need at least trunk r71890 for this patch. Maybe trunk r71890 or
 later without the attached patch fixes the problem already.

 The errors must be somehow related to G_read_compressed() because only
 FCELL/DCELL maps use G_read_compressed() while CELL maps use G_expand()
 directly.

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Ticket URL: <https://trac.osgeo.org/grass/ticket/2764#comment:15>
GRASS GIS <https://grass.osgeo.org>