bug#81599: 30.2; Doc of `buffer-file-name'

> From: "Drew Adams" <[email protected]>
> Date: Tue, 11 Aug 2026 13:53:14 -0700
> 
> Neither the doc string nor the Elisp manual entry says what form of file
> name is used.  It should say (it seems) that the expanded absolute file
> name is returned.  This way, users will know that (1) the name is
> absolute, not relative, and (2) if they want it abbreviated then they
> need to use `abbreviate-file-name'.
> 
> Contrast this with the manual entry for `buffer-file-truename', which
> states that the returned name is abbreviated.  And it even links to the
> manual pages for Truenames and `abbreviate-file-name'.
> 
> The manual node for this, `Buffer File Name', does say this:
> 
>  "Most of the time, the buffer name is the same as the nondirectory part
>   of the buffer file name, but the buffer file name and the buffer name
>   are distinct and can be set independently."
> 
> >From that one could surmise that the buffer file name has more than a
> nondirectory part.  And the examples given show expanded absolute names.
> But it's still important for the doc of the function and the variable to
> be explicit about what form of file name is used.

You already reported this, see bug#81340.

Closing, as that bug was resolved by fixing the documentation.