Re: [Evolution] Evolution forces conversion from mbox to maildir

[mwrsa web de]

> Gesendet: Mittwoch, 11. Dezember 2019 um 13:35 Uhr
> Von: "Milan Crha via evolution-list" <evolution-list gnome org>
> An: evolution-list gnome org
> Betreff: Re: [Evolution] Evolution forces conversion from mbox to maildir
>
> On Wed, 2019-12-11 at 13:08 +0100, Martin Wagner wrote:
> > Thank you very much @Milan for pointing out the actuall issue, which
> > was anough information for me to search and solve the rest.
>
>       Hi,
> the main question, at least from my point of view, is: how did that
> happen? It looks like a data corruption to me. Evolution surely did not
> delete the Outbox folder, neither your mails. I'd be cautious and watch
> for other issues, maybe it'll reoccur, until you find and fix the cause
> of it.
>
> In any case, I'm happy you made it work again.
>       Bye,
>       Milan

Good question, and the combination of circumstances may lead to the solution:

The culprit may be FSlint (and me, myself and I ofc.), and Evolution itself to a certain extent. Let me sum 
up.

1. It happened just before the backup, because Evolution worked before. I fetched my mails to have them 
included in that backup.
2. The Outbox folder is empty, usually, except for three more empty folders, I assume?!
3. FSlint has an option to batch delete all empty folders under ~/
4. I ran FSlint last thing before the latest backup.

I surely think you see what I did there. The only question Evolution has to take responsibility for is this: 
Is it really the best and safest way to determine the mail storage format by the presence of an empty folder 
(and maybe the presence of the corresponding meta file)? This part looks to me like a little programming 
shortcut, not to name it q&d programming (no insult intended). And the lack of documentation of that fact. At 
least I didn't find any of it before I entered the mailing list.
Well, I'll add an article on it to my measly tiny half abandoned blog over at mwrsa.de (in German though, 
obviously), documenting the progress and what I mentioned above.

@Milan again: Do you have a clue why simply recreating the Outbox folder did not work, and neither worked 
copying the folder and its meta file out of the backup? Like I wrote yesterday: I could open Evolution that 
way, but no other folder but the inbox were accessible.
I would love to include a solution for those wo do not have a regular backup like I do.

Next question: Is there an easy way to ask for that little change in Evolution? Like adding a value to its 
~/.config/evolution folder somewhere, like <mailformat="mbox|maildir"> AND a routine if the value is absent 
then checking for the Outbox folder and - to make sure - maybe another one or two indicators and then adding 
the value accordingly.

TC, Martin