Arc/Info Binary Grid Bug

[warmerdam]

Stephen Cheesman (geosoft) reports that a particular Arc/Info grid crashes 
in the read block function of gridlib.c.  He has placed the grid at:

 ftp://gdal.velocet.ca/pub/incoming/USGSjsd.zip

I have reproduce the bug (crashes OpenEV).

Also of note:
 o The adf.prj file (STATEPLANE) is not supported properly.
 o There is a report from the library that there is a 0x2E grid tile and
   that this is not supported.

[warmerdam]

Stephen,

Much of my testing suggests that the coverage you provided is corrupt
in some manner.  At a certain point (roughly 10MB into the main file) the
tile data no longer makes sense.  Invariant assumptions like the block size
written in the data file matching the index file start failing and nothing
makes sense. 

What are the possibilities that something could have gone seriously wrong
with the data?  

I tried opening the file with the ESRI supplied DLL (avgridio.dll) and it
also fails (crashes) at the same point as my programs.  

I could try and make my code more bullet proof to avoid the crash but I am
doubtful the file is recoverable. 

Best regards,

-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam@pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent

[warmerdam]

Work done (some weeks ago now) to make the reader much more resilient to
errors.  The file still has missing tiles, but doesn't cause a crash in 
the low level code or GDAL.