Bug #36246 for Compress-Bzip2: Compressing an empty file yields an empty (i.e. invalid) file

Wed May 28 10:48:20 2008 GWOLF [...] cpan.org - Ticket created

Subject:

Compressing an empty file yields an empty (i.e. invalid) file

Hi, I'm filing this bug as a followup to the corresponding bug report in Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?archive=no&bug=464205 Andres Mejia, the bug submitter, found out that trying to compress a zero-byte file results in creating a zero-byte .bz2 file - which is clearly invalid. I am attaching here the bzip2test test case he sent to illustrate the point (patched with Jeffrey Ratcliffe's further comment - see bug report). I'll also attach the file that fixes this problem. I am uploading a patched release to Debian, but I'd be most grateful if you include this fix (or any fix, of course ;-) ) to your code.

Subject:

bzip2test

Download bzip2test
application/octet-stream 1.3k

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Wed May 28 10:49:32 2008 GWOLF [...] cpan.org - Correspondence added

On Wed May 28 10:48:20 2008, GWOLF wrote: Show quoted text

> Hi, > I'm filing this bug as a followup to the corresponding bug report in

Debian: Show quoted text

> > http://bugs.debian.org/cgi-bin/bugreport.cgi?archive=no&bug=464205 > > Andres Mejia, the bug submitter, found out that trying to compress a > zero-byte file results in creating a zero-byte .bz2 file - which is > clearly invalid. I am attaching here the bzip2test test case he sent to > illustrate the point (patched with Jeffrey Ratcliffe's further comment - > see bug report). > > I'll also attach the file that fixes this problem. I am uploading a > patched release to Debian, but I'd be most grateful if you include this > fix (or any fix, of course ;-) ) to your code.

--- libcompress-bzip2-perl-2.09.orig/Bzip2.xs +++ libcompress-bzip2-perl-2.09/Bzip2.xs @@ -1485,8 +1485,6 @@ return -2; } - if (nUncompressed == 0) return 0; - while (True) { if ( obj->run_progress == 0 ) { ret = BZ2_bzCompressInit ( &(obj->strm), obj->blockSize100k, obj->verbosity, obj->workFactor ); @@ -2253,12 +2251,10 @@ else bufp = SvPV(buf, len); - if (len) { - RETVAL = bzfile_write( obj, bufp, len); + RETVAL = bzfile_write( obj, bufp, len); - if ( RETVAL > 0 ) + if ( RETVAL > 0 ) SvCUR_set( buf, RETVAL ); - } } OUTPUT: --- libcompress-bzip2-perl-2.09.orig/debian/changelog +++ libcompress-bzip2-perl-2.09/debian/changelog @@ -0,0 +1,26 @@ +libcompress-bzip2-perl (2.09-1.2) unstable; urgency=low + + * Non-maintainer upload. + * Fix bug compressing empty files (closes: #464205) + + -- Jeffrey Ratcliffe <Jeffrey.Ratcliffe@gmail.com> Wed, 21 May 2008 20:55:33 +0200 + libcompress-bzip2-perl (2.09-1.1) unstable; urgency=low * Non-maintainer upload.

Wed May 28 10:49:35 2008 GWOLF [...] cpan.org - Correspondence added

Patch for the bug included here

--- libcompress-bzip2-perl-2.09.orig/Bzip2.xs +++ libcompress-bzip2-perl-2.09/Bzip2.xs @@ -1485,8 +1485,6 @@ return -2; } - if (nUncompressed == 0) return 0; - while (True) { if ( obj->run_progress == 0 ) { ret = BZ2_bzCompressInit ( &(obj->strm), obj->blockSize100k, obj->verbosity, obj->workFactor ); @@ -2253,12 +2251,10 @@ else bufp = SvPV(buf, len); - if (len) { - RETVAL = bzfile_write( obj, bufp, len); + RETVAL = bzfile_write( obj, bufp, len); - if ( RETVAL > 0 ) + if ( RETVAL > 0 ) SvCUR_set( buf, RETVAL ); - } } OUTPUT: --- libcompress-bzip2-perl-2.09.orig/debian/changelog +++ libcompress-bzip2-perl-2.09/debian/changelog @@ -0,0 +1,26 @@ +libcompress-bzip2-perl (2.09-1.2) unstable; urgency=low + + * Non-maintainer upload. + * Fix bug compressing empty files (closes: #464205) + + -- Jeffrey Ratcliffe <Jeffrey.Ratcliffe@gmail.com> Wed, 21 May 2008 20:55:33 +0200 + libcompress-bzip2-perl (2.09-1.1) unstable; urgency=low * Non-maintainer upload.

Tue Mar 26 15:53:28 2013 RURBAN [...] cpan.org - Correspondence added

Thanks. The fix plus a testcase will be in the upcoming 2.10. See https://github.com/rurban/Compress-Bzip2/commit/810e08007a39eebd136c505bddddab99f289fdea -- Reini Urban

Tue Mar 26 15:53:29 2013 The RT System itself - Status changed from 'new' to 'open'

Tue Mar 26 20:05:53 2013 RURBAN [...] cpan.org - Status changed from 'open' to 'resolved'