Thank you for the hints.

Attached a diff -u version.

The patch in principle is unrelated to nextcloud. That's just my
use case. The addiditional TTL setting gives a hint to clients
when to reload an imported ics file that was exported from org.

Is there any document how to setup an org-mode developer environment?
Normally I use git, but I even struggled to use org from elpa instead
of the built-in version, so I avoided touching this house of cards :-)

Probably I should use a git clone instead of elpa, if I want to work
on org?

Thx for the feedback!
Detlef



Am Mon, 3 Jan 2022 13:08:54 +0700
schrieb Max Nikulin <manikulin@gmail.com>:

> On 02/01/2022 20:28, Detlef Steuer wrote:
> >   
> >> This is my first try ever to contribute anything in elisp.  
> 
> Thanks for the patch. It is tracked on https://updates.orgmode.org/
> 
> It is easier to review and to apply a patch when it it is prepared in 
> context format ("-u" option of diff). Several additional lines of
> code above and below changed ones makes the patch more tolerate to
> unrelated changes in the same file. It is a hint for humans as well.
> 
> See info "(diffutils) Tips for Patch Producers" 
> https://www.gnu.org/software/diffutils/manual/html_node/Tips-for-Patch-Producers.html 
> or "NOTES FOR PATCH SENDERS" section in "man patch".
> 
> If you have never used git (or other VCS) before then it is likely an 
> overkill for a single patch, diff output with manually added
> description is OK. However you may find such tool rather convenient
> as number of changes will grow. See
> https://orgmode.org/worg/org-contribute.html for some hints addressed
> to contributors.
> 
> I am not a nextcloud or org-icalendar user, so while I expect that 
> suggested change is an improvement, I can say nothing concerning the
> code.
> 
>