bug#15109: 24.3.50; doc of `x-get-selection, `selection-converter-alist', `xselect-convert-to-*'

[Drew Adams]

> > By "this" you apparently mean `x-get-selection'.  So yes, part
> > 1 of this bug has been fixed.  But part 2 has not been fixed.
> > `selection-converter-alist' certainly does not have "a huge doc
> > string now".  Reopening.
> 
> It certainly has a huge doc string on the trunk; see below.
> 
> Windows issue?
> 
> selection-converter-alist is a variable defined in `xselect.c'.
> Its value is shown below.
> 
> Documentation:
> An alist associating X Windows selection-types with functions.
> These functions are called to convert the selection, with three
> args:
> the name of the selection (typically `PRIMARY', `SECONDARY', or
> `CLIPBOARD');
> a desired type to which the selection should be converted;
> and the local selection value (whatever was given to `x-own-
> selection').
> 
> The function should return the value to send to the X server
> (typically a string).  A return value of nil
> means that the conversion could not be done.
> A return value which is the symbol `NULL'
> means that a side-effect was executed,
> and there is no meaningful selection value.
> 
> Value: ((TEXT . xselect-convert-to-string)
>  (COMPOUND_TEXT . xselect-convert-to-string)
>  (STRING . xselect-convert-to-string)
>  (UTF8_STRING . xselect-convert-to-string)
>  (TARGETS . xselect-convert-to-targets)
>  (LENGTH . xselect-convert-to-length)
>  (DELETE . xselect-convert-to-delete)
>  (FILE_NAME . xselect-convert-to-filename)
>  (CHARACTER_POSITION . xselect-convert-to-charpos)
>  (LINE_NUMBER . xselect-convert-to-lineno)
>  (COLUMN_NUMBER . xselect-convert-to-colno)
>  (OWNER_OS . xselect-convert-to-os)
>  (HOST_NAME . xselect-convert-to-host)
>  (USER . xselect-convert-to-user)
>  (CLASS . xselect-convert-to-class)
>  (NAME . xselect-convert-to-name)
>  (ATOM . xselect-convert-to-atom)
>  (INTEGER . xselect-convert-to-integer)
>  (SAVE_TARGETS . xselect-convert-to-save-targets)
>  (_EMACS_INTERNAL . xselect-convert-to-identity))