Re: org-calendar-holiday and local holidays

[Alexis <flexibeast@gmail.com>]

On 2015-03-03T02:26:37+1100, Jorge A. Alfaro-Murillo said:

 JAA> Alexis writes:

 >> 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.

 JAA> You do not need to add that, calendar-holidays appends JAA> 
 holiday-local-holidays when holidays.el is loaded, just restart 
 JAA> emacs.

Not in my Emacs (manually compiled 24.4.1, the most recent 
official stable release). My `local-holidays` variable was set for 
years, such that only as part of trying to help the OP did i 
notice that it's been obsoleted; the documentation for it says:

      This variable is an alias for `holiday-local-holidays'. 
      This variable is obsolete since 23.1; use 
      `holiday-local-holidays' instead.

So i changed my init to refer to `holiday-local-holidays` instead 
of `local-holidays`, and restarted Emacs, and the issue persisted: 
the value of `holiday-local-holidays` is /not/ included in 
`calendar-holidays` by default. The `(setq calendar-holidays ...` 
line i described above is necessary to work around this.

 JAA> It is also not a documentation bug, at least in my emacs 
 JAA> (25.0.50.1) the documentation of calendar-holidays says 
 clearly:

 JAA> "Note that these variables [`holiday-other-holidays', JAA> 
 `holiday-general-holidays', `holiday-local-holidays', JAA> 
 `holiday-christian-holidays', `holiday-hebrew-holidays', JAA> 
 `holiday-islamic-holidays', `holiday-bahai-holidays', JAA> 
 `holiday-oriental-holidays' and `holiday-solar-holidays'] have 
 JAA> no effect on `calendar-holidays' after it has been set JAA> 
 (e.g. after the calendar is loaded). In that case, customize JAA> 
 `calendar-holidays' directly."

In 24.4.1, the documentation is phrased differently; it says:

    Additional holidays are easy to add to the list, just put them 
    in the list `holiday-other-holidays' in your init file. 
    Similarly, by setting any of `holiday-general-holidays', 
    `holiday-local-holidays', `holiday-christian-holidays', 
    `holiday-hebrew-holidays', `holiday-islamic-holidays', 
    `holiday-bahai-holidays', `holiday-oriental-holidays', or 
    `holiday-solar-holidays' to nil in your init file, you can 
    eliminate unwanted categories of holidays.

    The aforementioned variables control the holiday choices 
    offered by the function `holiday-list' when it is called 
    interactively.

    They also initialize the default value of `calendar-holidays', 
    which is the default list of holidays used by the function 
    `holiday-list' in the non-interactive case.  Note that these 
    variables have no effect on `calendar-holidays' after it has 
    been set (e.g. after the calendar is loaded).  In that case, 
    customize `calendar-holidays' directly.

    The intention is that (in the US) `holiday-local-holidays' be 
    set in site-init.el and `holiday-other-holidays' be set by the 
    user.

It's the fact that, despite the above docstring, and that, as i 
described above, setting the value of `holiday-local-holidays` has 
no direct effect on `calendar-holidays` /even after a restart of 
Emacs/, that led me to suggest there might be a code bug or a 
documentation bug (e.g. maybe some variable needed to be set to 
`t` to ensure the value of `holiday-local-holidays` gets included 
in `calendar-holidays`).

Since things work for you, and the phrasing for the documentation 
for `calendar-holidays` has changed between the most recent stable 
release and the development version of Emacs you're using, my 
guess is that there is indeed a bug in 24.4.1 and earlier that has 
subsequently been fixed. Later today i'll try building from the 
first 24.5 pretest and the master branch, and examine what happens 
with `holiday-local-holidays` / `calendar-holidays` in both 
instances.


Alexis.