%config files and upgrade to F11 - consider noreplace

[Miloslav Trmač]

Bill Nottingham píše v St 25. 02. 2009 v 17:01 -0500:
> Miloslav Trmač (mitr at volny.cz) said: 
> > Because the Fedora 11 RPM packages will use SHA-256 for file digests in
> > the RPM headers, upgrades from earlier releases to Fedora 11 will
> > replace user-modified %config files (without noreplace) by their
> > original versions, and rename the user-modified files to *.rpmsave.
> > 
> > The Fedora packaging guidelines already suggest using %config(noreplace)
> > in most cases:
> > https://fedoraproject.org/wiki/PackagingGuidelines#Configuration_files .
> > 
> > Please review use of %config without noreplace in your packages, and add
> > noreplace if appropriate.  The list of affected packages is below.
> 
> Given that it's comparing hashes, and the old hash is *obviously* of a
> different type than the new hash, why can't these sorts of conflicts
> be caught?
rpm recognizes that the hash changed, but what can it do?

- there is a config file
- the config file was modified by the user
- the update package may or may not contain a different version
  of the config file than the old package.
=> the only things rpm can do is:
- leave the modified config file as is
  (this is what rpm does if the hashes are equal, i.e. the update 
   doesn't change the config file)
  X if the update did update the config file, the updated config file
    would not be installed - but %config means the updated config file
    should be installed
  X this loses data (user would have to dig into the updated rpm package
    manually to get the updated config file, and would get no
    notification about the unused updated config file)
- save the updated config file as .rpmnew
  X there would be no difference between %config and %config(noreplace),
    changing the semantics
- save the modified config file as .rpmsave
  X moves modified files to .rpmsave even if the update doesn't change
    the config file

	Mirek