Re: default-text-properties

[Luc Teirlinck <teirllm@dms.auburn.edu>]

I understand now.  I did not read the code carefully enough and I
forgot to remember something extra I did yesterday.

Fget_text_property calls `textget' which calls `lookup_char_property'
which contains the code:

  tail = Fassq (prop, Vchar_property_alias_alist);
  if (NILP (tail))
    return tail;

In other words, default-text-properties is only consulted for foo if
char-property-alias-alist contains foo as a key.  Hence:

(setq default-text-properties '(foo 69)
                char-property-alias-alist nil)
nil
(set-text-properties 1 2 nil)
t
(get-text-property 1 'foo)
nil

But (I must have done something like this yesterday):

(setq default-text-properties '(foo 69)
                char-property-alias-alist '((foo bar)))
((foo bar))
(set-text-properties 1 2 nil)
t
(get-text-property 1 'foo)
69

Completely undocumented (actually explicitly contradicted with the
above example) in the Elisp manual and the relevant docstrings.  I
suspect this is a bug.  If so, it is trivial to fix.  If intentional,
it should be properly documented.

Sincerely,

Luc.