Re: [BUG] Inconsistent behaviour of TODO + COMMENT + TODO dependencies + agenda? [9.5 (9.5-g0a86ad @ /home/ignacio/.emacs.d/elpa/org-9.5/)]

[Ihor Radchenko]

Sorry for the late reply.

Ignacio Casso <ignaciocasso@hotmail.com> writes:

> I was going to write one, but I have found further inconsistencies and
> incomplete documentation and I think we should clearly define first how
> we want dependencies to behave. According to the Org Mode documentation
> and the docstrings of `org-enforce-todo-dependencies' and
> `org-block-todo-from-children-or-siblings-or-parent', tasks are blocked
> when:
>
>   1. The task has undone children tasks.
>
>   2. A task has a parent with the property :ORDERED:, and there
>      are undone sibling tasks prior to the current task
>
>   3. The parent of the task is blocked because it has siblings that should
>      be done first, or is child of a blocked grandparent TODO entry."
>
> But they are actually blocked when:
>
>   1. The task has undone DESCENDANT tasks (i.e., undone children of
>   children also block)
>
>   2. A task has a parent with the property :ORDERED:, and there
>      are sibling tasks prior to the current task which are undone OR
>      HAVE UNDONE DESCENDANTS
>
>   3. The parent of the task is blocked because it has siblings that should
>      be done first, or is child of a blocked grandparent TODO entry. BUT
>      THE TASK IS NOT BLOCKED E.G., IF ITS GRANDPARENT IS BLOCKED AND IS
>      PARENT IS DONE OR HAS NO TODO STATE.

This is indeed inconsistent. I suspect that the main reason is an
omission in the code when a single re-search-forward is used to check if
there are undone descendant tasks. If not and the code deliberately
checks things not mentioned in the manual, we may need to look further
and dig into the mailing list/git logs.

> So my other issues are:
>
> - Remarks in upper case in points 1 and 2 should be clarified in the
>   documentation and docstrings, if that is actually the desired
>   behaviour and not a bug. Otherwise, they should be fixed. I can do
>   that in the same patch.

I think that they are mostly clarified in "5.2.7 TODO dependencies"
section of the manual, except slightly confusing passage about subtasks:

5.2.7 TODO dependencies ::

The structure of Org files—hierarchy and lists—makes it easy to define
TODO dependencies.  Usually, a parent TODO task should not be marked as
done until all TODO subtasks, or children tasks, are marked as done.
                    ^^^^^^^^
Sometimes there is a logical sequence to (sub)tasks, so that one subtask
cannot be acted upon before all siblings above it have been marked as
done.  If you customize the variable ‘org-enforce-todo-dependencies’,
Org blocks entries from changing state to DONE while they have TODO
children that are not DONE.  Furthermore, if an entry has a property
‘ORDERED’, each of its TODO children is blocked until all earlier
siblings are marked as done.  Here is an example:

-- 
Ihor Radchenko,
Org mode contributor,
Learn more about Org mode at https://orgmode.org/.
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