Directory Links (and a bug?)

[Achim Gratz <Stromeko@nexgo.de>]

Making a directory link like this: [[file://bla/fasel/]] will open that
folder in explorer on Windows at work, which is nice since I can just
keep a bunch of those in my notes.org file and fire them up whenever I
need to (the history in Explorer is never that helpful).  I have since
learned that there's a special form to make that link open in EMACS
[[file+emacs://bla/fasel/]] and that fires up dired.  Or, if I had set
up org-mode so that file:-links would open inside EMACS, I could use
[[file+sys://bla/fasel/]] to force the link to open in an external
application.  So far so good... what I'd want in addition is to have the
link open in dired with wildcard patterns (giving a file name that
doesn't exist or looks like a directory gets me into dired, but doesn't
give it the "file" part as a wildcard argument) or alternatively
directly into vc-dir like [[file+dired://bla/fasel/*.org]] and
[[file+vc-dir://bla/fasel/]].  Whatever the part after the "+", the
links should be exported like normal file: links.

The link abbrevs don't really work for this as they are supposed to
return a string and not go off into another buffer (it does sort-of
work, but I suspect it breaks exporting etc.).  An elisp link works, but
gets me a Yes/no question and shows up verbatim in export, not as link.
The +sys/+emacs links (and some abbrevs) export as file:-links with the
complete link-syntax appended as anchor (like
file:///bla/fasel/#file+emacs://bla/fasel/ - this works, but that looks
like a bug to me or an accidental feature at least).

Now, looking into the code I see that there's a lot of special casing
going on and no obvious hooks to tap into and that I don't really
understand what's going on...  If anybody could shed light on how this
is all supposed to work "under the hood" and how some extra link methods
would need to be implemented, please discuss.


Achim.