F21 System Wide Change: lbzip2 as default bzip2 implementation

[Al Dunsmuir]

On Wednesday, April 2, 2014, 4:27:55 PM, Zbigniew Jędrzejewski-Szmek wrote:

>> ** possibly adjust spec files to require or build-require lbzip2 instead of 
>> bzip2. 
> Is this necessary? Wouldn't it be better to have lbzip2 Provide bzip2
> or something so that updating all those packages is not necessary,
> and also that people who prefer normal bzip2 can still use it?

This  sounds like a very intrusive change that in the worst case could
introduce  errors  and  expose user data to permanent loss without any
means to recover.

Many tools read and write zip files. The actual ZIP standard format is
controlled by (coordinated by) PKZIP via their application note. There
is a lot of discussion about common extensions, but each tool can have
their own private extensions that may be incompatible.

The  InfoZIP  team  that  gives  you the zip and unzip tools has added
support   for   the  bzip2  and  lzma  compression  and  decompression
algorithms,  as  well  as  AES encryption/decryption in their upcoming
beta  release. I've been involved in reworking U*IX build support, and
working towards better support on mainframe platforms (z/OS, z/VM) and
AIX. I do all my primary development and testing on Fedora, but others
have their own preferred platform.

This  implementation  has  been built and extensively tested using the
current  release  of the real bzip2 library. Substituting a completely
different  library  implementation without going through extensive and
explicit validating and testing is risky and unreasonable. At best, it
would   complicate   problem  reporting,  reproduction,  analysis  and
correction.

The  libzip  effort  is not part of the InfoZIP project. They may have
created a wonderful library, but it will not have identical interfaces
and behaviours as the original bzip2 library.

Let the upstream tools decide which bzip implementation(s) to support,
and do the necessary validation to ensure that it all works correctly.
It  is  the  upstream  tool's  reputation that would be damaged if the
Fedora  library  caused  user  data  to be lost. Let them do their job
correctly.

Final  gloomy  thought  of  the  day: Breaking zip files could you are
breaking the actual tool used for backups. That makes data loss a very
permanent problem.

Al