[vtk-developers] [VTK 0014008]: vtkmetaio - compress/uncompress doesn't handle the last bytes properly when compress overflows.

[Mantis Bug Tracker]

The following issue has been SUBMITTED. 
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http://www.vtk.org/Bug/view.php?id=14008 
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Reported By:                Gert Wollny
Assigned To:                
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Project:                    VTK
Issue ID:                   14008
Category:                   (No Category)
Reproducibility:            have not tried
Severity:                   minor
Priority:                   normal
Status:                     backlog
Project:                    TBD 
Type:                       incorrect functionality 
Resolution:                 open
Fixed in Version:           
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Date Submitted:             2013-04-12 11:06 EDT
Last Modified:              2013-04-12 11:06 EDT
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Summary:                    vtkmetaio - compress/uncompress doesn't handle the
last bytes properly when compress overflows.
Description: 
MET_PerformCompression doesn't handle it properly when the compression output is
larger then the input. 

A test case is attached that compresses and uncompressed N bytes (N \in [1,300])
and checks the result. On one hand it uses a constant value for all N bytes,
here N=1...4 fail. On the other hand the array is filled according to a[i] =
char(i). Here all cases  (N < 273) fail, i.e. the last output bytes are not
correct. 
In all failed cases the "compressed" output was larger than the input. 

I think this indicates that the output buffer overflow during compression is not
handled correctly. 

The attached test program writes out all failing comparisons. If an abitrary
additional  command line parameter is given, also some info about the successful
test is written out. The according CMakeLists.txt is given as comment in the C++
file. 


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Issue History 
Date Modified    Username       Field                    Change               
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2013-04-12 11:06 Gert Wollny    New Issue                                    
2013-04-12 11:06 Gert Wollny    File Added: test_MET_Compression.cc             
      
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