Bug #74281 for Archive-Zip: Corrupt archive generated when changing compression methods (inc possible patch)

If you create an archive using addMember from an existing archive then change the desired compression method then the resulting archive is corrupt. Here's a quick example:- #!/usr/bin/perl -w use strict; use Archive::Zip qw( :CONSTANTS :ERROR_CODES ); my $csv_zip = Archive::Zip->new(); my $src_zip = Archive::Zip->new('source.zip'); map { my $member = $csv_zip->addMember( $_ ); # NOTE: changing the method here causes the issue $member->desiredCompressionMethod( COMPRESSION_STORED ); } $src_zip->members(); my $csv_filename = 'output.zip'; my $status = $csv_zip->writeToFileNamed( $csv_filename ); if ( AZ_OK != $status ) { print STDERR "Failed to create '$csv_filename' ($status)" ); exit 1; } exit 0; The cause for this seems to be that the calculation of headerFieldsUnknown in Zip::Member->_writeToFileHandle doesn't take into account a change of existing compression method and hence fails to rewrite the local file headers. Assuming this is the case, the attached patch fixes this. Regards Steve ================================================ This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337 or return the E.mail to postmaster@multiplay.co.uk.