[Boost-bugs] [Boost C++ Libraries] #5237: filtering_ostream produce incorrect empty files with gzip_compressor and other filters

Subject: [Boost-bugs] [Boost C++ Libraries] #5237: filtering_ostream produce incorrect empty files with gzip_compressor and other filters
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2011-02-27 11:07:17

#5237: filtering_ostream produce incorrect empty files with gzip_compressor and
other filters
----------------------------------+-----------------------------------------
 Reporter:  come.raczy@…          |       Owner:  turkanis 
     Type:  Bugs                  |      Status:  new      
Milestone:  To Be Determined      |   Component:  iostreams
  Version:  Boost 1.44.0          |    Severity:  Problem  
 Keywords:                        |  
----------------------------------+-----------------------------------------
 The attached program should produce an empty gzip file, using the
 gzip_compressor:
 {{{
 int main()
 {
     using namespace boost::iostreams;
     filtering_ostream os;
     os.push(boost::iostreams::gzip_compressor());
     os.push(boost::iostreams::file_sink("emptyGzipBug.txt.gz"));
 }
 }}}
 The resulting file is not a gzip file:
 {{{
 $ hexdump emptyGzipBug.txt.gz
 0000000 0003
 0000002
 $ zcat testGzipEmpty.txt.gz

 zcat: testGzipEmpty.txt.gz: not in gzip format
 $
 }}}

 A workaround is to manually force an empty write into the stack of
 components with something like this:
 {{{
     char dummy = 'b';
     os.component<gzip_compressor>(0)->write(*os.component<file_sink>(1),
 &dummy, 0);
 }}}
 The problem seems to affect all versions, including Boost 1.46.0

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/5237>
Boost C++ Libraries <http://www.boost.org/>
Boost provides free peer-reviewed portable C++ source libraries.