[Sugar-devel] Datastore shared between 0.84 and 0.86 systems

[Tomeu Vizoso]

On Tue, Sep 22, 2009 at 17:57, Jonas Smedegaard <dr at jones.dk> wrote:
> Hi,
>
> I guess that if a user creates a sugar environment (i.e. ~/.sugar) using
> 0.84 or older and then switches to 0.86 then the datastore is updated.
>
> But what happens the other way around?  Is the data usable, or does it get
> corrupted, or does it maybe get moved off so is experienced as lost by the
> user?
>
> I ask because I consider shipping next stable Debian release with *both*
> 0.84 and 0.86 (and possibly also 0.87 or 0.88).  Only a single Sucrose
> branch can be installed at once, but an admin can relatively easy swith from
> one to another, and then back again - wreaking havoc for users if the system
> does not sanely handle it.
>
> Also imagine the case of diskless clients offered the choice of multiple
> appliation servers running different versions of Sucrose, all using same
> /home NFS storage.
>
> In the document world, it is often used to add a version hint.  I know that
> the DtP application Scribus handles not only upgrades from 1.3.1- and
> 1.3.2-produced documents to the newer 1.3.3 (which used a slightly different
> file format), but also the older versions properly identifies too *new*
> documents and refuses to open them, instead informing about the version
> mismatch.
>
>
> Even if current 0.84 (and 0.82!) does not currently implement version
> checking, I would very much appreciate if such functionality was added now
> as a bugfix release.
>
>
> Hope you see the point of this, and that it is easy to implement - most easy
> being just replying "we thought of that ages ago and it already works
> sanely!" :-)

Sure I see the point. I *think* that there are good chances that the
0.84 DS will be able to read a dir converted to the 0.86 format,
because the only changes were in the index and in a backwards
compatible way, AFAICS.

Could someone give this a try and report the results?

The format version number of the dir is in ~/.sugar/default/datastore/version

Thanks,

Tomeu


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