Re: org-calendar-holiday and local holidays

[Alexis <flexibeast@gmail.com>]

[Crossposted to the help-gnu-emacs list, for possible advice on 
whether or not this involves a bug in GNU Emacs.]

On 2015-03-02T09:29:09+1100, Melleus said:

 M> I'm afraid to ask. But... Anyway. Does 
 %%(org-calendar-holiday) M> know about holiday-local-holidays? 
 I'm not programmer, sorry. I've M> set up those local holidays 
 but cannot see them in my agenda.

You can examine the definition of an ELisp function by:

1. typing C-h f whilst on a function;
2. typing RET to take you to the documentation for that function;
3. typing TAB then RET to take you to the function definition.

Starting with point on `org-calendar-holiday`, we find that:

- `org-calendar-holiday` calls (if available) 
  `calendar-check-holidays` or (otherwise) 
  `check-calendar-holidays`;

- `calendar-check-holidays` calls `calendar-holiday-list`;

- `calendar-holiday-list` makes use of the `calendar-holidays` 
  variable.

We can examine the documentation for the `calendar-holidays` 
variable by moving point onto and typing C-h v RET. On my setup 
(manually compiled Emacs 24.4.1 on Debian Wheezy(+updates) x86_64 
together with Org 20150223), the documentation suggests that 
`calendar-holidays` makes use of the `holiday-local-holidays` 
variable; and the documentation for `holiday-local-holidays` 
merely refers us back to the documentation for 
`calendar-holidays`.

When i scroll down to look at the current value of 
`calendar-holidays`, however, i see that neither the current value 
nor the original value makes any reference to the 
`holiday-local-holidays` variable. And indeed, when i examine my 
agenda for next Monday, which is a local holiday i've specified in 
`holiday-local-holidays`, i can't see that local holiday. To fix 
this, i use M-: to evaluate:

    (setq calendar-holidays (append calendar-holidays 
    holiday-local-holidays))

after which the local holiday next Monday appears in my Org 
agenda.

Given the documentation for the `calendar-holidays` variable, the 
fact that i need to manually add the value of the 
`holiday-local-holidays` variable to `calendar-holidays` seems to 
me like it might be a coding or documentation bug in Emacs .... ?


Alexis.