webdav calendar goes into read-only mode after an extended period

[none]

hi -

i'm using lightning 0.3.1 on thunderbird 1.5.0.12 - i store my data in
an ics file over secure webdav. i access the file from my work machine
and from my home machine.

if i leave my mail client open for an extended period of time - eg,
overnight - and then try to modify the calendar, i'm given an error and
the calendar is put in read-only mode.

i thought it might be due to accessing it between different clients
(work and home), but my understanding is that lightning reads and
updates the entire file before saving a change to avoid conflicts.

is this a known issue?

thanks

[lionel valero]

Yes,

As far as i know, lightning/sunbird does not handle concurrent access to
an ics file.

Regards.

[Torsten Lilge]

This was my understanding, too. But as far as I know, sunbird/lightning
does not yet use the lock mechanism provided by webdav.

> is this a known issue?

See bugs https://bugzilla.mozilla.org/show_bug.cgi?id=329570 and
https://bugzilla.mozilla.org/show_bug.cgi?id=327933

[pkoe...@online.de]

Hi there

> This was my understanding, too. But as far as I know, sunbird/lightning
> does not yet use the lock mechanism provided by webdav.

As far as i see, Sunbird sends an If-Header to the WebDAV-Server,
asking it only to accept the PUT-Request when the T-Tag has NOT
changed. The E-Tag changes each time the .ics-File is changed. So
sunbirg gets the Error 412 "precondition failed" back and cancels the
request.

What should happen instead is, when such an error occurs during a
calendar-publishing-operation, sunbird should first reload the
calendar, do the task (adding/changing/deleting an entry) again and
try again to publish the calendar.

When there was also a regular update of the external calendars (like
in Thunderbird for a POP3-Account), i think rhere would be no problem
anymore with accessing one WebDAV/ICS-Calendar with multiple Clients,
as long as only one client performs a write-operation at a time..

Maybe these Tasks could be performed by an extension.
Best regards,
Peter Körner