[Boost-bugs] [Boost C++ Libraries] #8150: gzip_compressor produces corrupt data when used with filtering_ostream

Subject: [Boost-bugs] [Boost C++ Libraries] #8150: gzip_compressor produces corrupt data when used with filtering_ostream
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2013-02-23 00:00:11

#8150: gzip_compressor produces corrupt data when used with filtering_ostream
---------------------------------------+------------------------------------
 Reporter:  matt@…                     |       Owner:  turkanis  
     Type:  Bugs                       |      Status:  new       
Milestone:  To Be Determined           |   Component:  iostreams 
  Version:  Boost 1.53.0               |    Severity:  Regression
 Keywords:                             |  
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 In some cases, the USE_CORRUPTING_OSTREAM path in the following program
 will produce corrupt gzip output (fails CRC and the de-gzipped file
 differs slightly from the original input). This does not occur for all
 data, so I will attach an input data file that triggers the error.

 This bug only affects gzip_stream when used with filtering_ostream. It
 does not affect filtering_istream usage.

 Bug reproduced on Mac 10.8.2, 64-bit, Apple LLVM version 4.2
 (clang-425.0.24) (based on LLVM 3.2svn), zlib 1.2.5 (dylib as shipped with
 Mac OS X), boost 1.53.0.

 Bug does not appear to be affected by compiler optimizations (-O0 and -Os
 tested).

 {{{
 #include <iostream>
 #include <fstream>
 #include <vector>
 #include <boost/iostreams/filter/gzip.hpp>
 #include <boost/iostreams/filtering_stream.hpp>
 #include <boost/iostreams/device/back_inserter.hpp>
 #include <boost/iostreams/copy.hpp>
 #include <boost/iostreams/device/array.hpp>
 #include <boost/iostreams/stream.hpp>
 #include <boost/iostreams/device/file_descriptor.hpp>

 int main(int argc, char *argv[])
 {
         std::vector<char> input;
         std::vector<char> output;

         boost::iostreams::file_descriptor_source source("inputdata");
         boost::iostreams::copy(source,
 boost::iostreams::back_inserter(input));

 #define USE_CORRUPTING_OSTREAM 1
 #if USE_CORRUPTING_OSTREAM
         boost::iostreams::filtering_ostream gzip_stream;
         gzip_stream.push(boost::iostreams::gzip_compressor());
         gzip_stream.push(boost::iostreams::back_inserter(output));
         gzip_stream.write(&input[0], input.size());
         boost::iostreams::close(gzip_stream);
 #else
         boost::iostreams::filtering_istream gzip_stream;
         boost::iostreams::stream<boost::iostreams::array_source>
 input_array(&input[0], input.size());
         gzip_stream.push(boost::iostreams::gzip_compressor());
         gzip_stream.push(input_array);
         boost::iostreams::copy(gzip_stream,
 boost::iostreams::back_inserter(output));
 #endif

         boost::iostreams::file_descriptor_sink
 destination("inputdata.gz");
         destination.write(&output[0], output.size());
 }
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/8150>
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