Fixes a bug in completing future tasks

[chuck-flowers]

Updates the repeater logic so that tasks which are completed before
their deadline has been reached, will properly repeat forward.

[kristijanhusak]

Can you please give an example? I'm not sure what's the difference between old and new code.

[chuck-flowers]

The issue that I've run into recently is that I have tasks for buying Christmas presents for friends and family. I have the DEADLINE for these TODOs set to <2022-12-25 Sun ++1y -40d>. I've already bought some of these presents so I'd like to mark them as complete using cit.

In the old logic, an entry would be made in the logbook but the deadline would not be updated because the while loop which incremented the DEADLINE date would increment only while the deadline was less than today. Since today is before the current DEADLINE no actual incrementing of the DEADLINE would occur.

Now with my new logic, at least one increment will occur before the condition of the while loop is checked. Essentially it's the difference between a while loop and a do ... while loop from other C-like languages. So now when I cit these Christmas present headlines, they are updated to <2023-12-25 Mon ++1y -40d> just like they are in Emacs.

I should note that for my emacs testing, I'm using the official emacs package as its distributed in Arch Linux in case that makes a difference.

EDIT: Fixed some typos

[chuck-flowers]

This commit also includes some slight changes and additional comments to the relevant code to help the next programmer understand more quickly what this code is doing.

[kristijanhusak]

Thanks for the explanation. It is indeed a bug. Could you also please add a test case for this in the date_spec, somewhere around here?

[chuck-flowers]

I've added a test as requested. It's the first Lua test I've ever had to write so please don't hesitate to let me know if any adjustments should be made.

[kristijanhusak]

Test looks good, just a minor tweak and it's good to go.

[kristijanhusak]

Everything looks great now, thanks!