bug#81516: 31.0.91; delete-file-local-variable(-prop-line) should delete "Local Variables" block (prop-line)

> Date: Wed, 29 Jul 2026 15:02:38 +0200
> From: Daniel Mendler via "Bug reports for GNU Emacs,
>  the Swiss army knife of text editors" <[email protected]>
> 
> When delete-file-local-variable is called for the last file-local
> variable, the "Local Variables" block is not removed. Similarly for
> delete-file-local-variable-prop-line, a remnant of the prop-line
> remains: ;; -*- -*-
> 
> While the remnants are not highly problematic, one still gets an error
> when the file is opened the next time:
> 
>   File mode specification error:
>   (error "Invalid search bound (wrong side of point)")
> 
> This suggest that the empty prop line (or the "Local Variables" block)
> should better be deleted.

I cannot reproduce this error.  I created a file with file-local
variables, then invoked delete-file-local-variable several times until
all the variables were deleted and what was left was the empty block:

  ;; Local Variables:
  ;; End:

Then I saved the buffer to its file, killed Emacs, and visited the
file in a new session -- I saw no errors.

If the recipe for reproducing the error is different, please describe
it in enough detail for me to be able to reproduce it.

I personally am not sure we should remove the empty block, if visiting
such a file doesn't signal an error (as I expect).