[PATCH] org-id: allow using parent's existing id in links to headlines

[Rick Lupton]

Hi,

Here is a small new feature for org-id that I have been using and finding 
useful. The patch adds the option to look for ancestors of the current headline 
that have an ID defined and use that together with a link search string to link 
to specific headlines, without needing every single headline to have its own ID.

For example if you have:

#+begin_example
* H1
:PROPERTIES:
:ID: abc
:END:

** H2
<point>Link to here
#+end_example

with `org-id-link-to-org-use-id' set to `t`, the result of org-store-link will 
be that "H2" has a new id generated, and the link is to that new ID: 
`[[id:new-id][H2]]`.

Now, with `org-id-link-to-org-use-id' set to `inherit`, "H2" is not modified, 
and the resulting link is `[[id:abc::*H2][H2]]`, which will still take you to 
the same place as long as the sub-heading is unique within the parent heading 
with an ID.

As an example, I find this useful in situations like this:

#+begin_example
* Project 1
:PROPERTIES:
:ID: project-1
:END:

** <2023-07-01> Meeting A
** <2023-07-08> Meeting B
** <2023-07-15> Meeting C
#+end_example

... so that I can link to specific meetings without needing every one to have 
its own org ID.

Feedback on the patch welcome. If you would like to merge this I will (I 
assume) need to sort out FSF copyright assignment and update ORG-NEWS and the 
manual.

Best
Rick

0001-lisp-org-id.el-Allow-using-a-parent-s-existing-id.patch
Description: Binary data