[Kdenlive-devel] How to handle support for old file format versions reliably

[jb]

On Saturday 22 November 2008 16.48:06 Mads Bondo Dydensborg wrote:
> Hi there
>
> In .kdenlive project files, the kdenlive_doc section is marked with a
> version. Is it correctly understood, that
>
> Kdenlive 0.5 used project file version (pfv) 0.6
> Kdenlive 0.6 used project file version (pfv) 0.7
> Kdenlive 0.7 uses project file version (pfv) 0.8

Kdenlive 0.6 was never released and still used pfv 0.6
Project file version 0.7 was only used for the Kdenlive 0.7 beta version, so 
no serious projects should have been done with that...

> I think we should redesign the flow to always call convertDocument. In
> convert document, we should first test against the older version, then
> repeatedly convert them up. We should also handle too-new versions. So,
> convertDocument would right now be changed to do
I agree that we should improve that. 


> The convertDocument should probably also indicate to the caller if the
> version actually changed, and allow the GUI to ask something like: "You
> have loaded a project saved in an older version of Kdenlives file format.
> The project has been succesfully converted to the new format. Would you
> like to write your project to a new file, or overwrite the old one". I am
> not sure this is strictly needed though, but perhaps it will save the day
> when we at some point introduces a bug in the conversion routines, or when
> somebody loads and edits a project in a new version of kdenlive, then
> discovers that it can no longer be loaded in an older version of kdenlive.

I totally agree that we should refuse to load new version files and warn about 
old version with a proposal to save to a new name.

If you have time to improve it you are welcome.

regards
jb