bug#46397: 27.1; Cannot delete buffer pointing to a file in a path that includes a file

[Eli Zaretskii <eliz@gnu.org>]

> From: Matt Armstrong <matt@rfc20.org>
> Cc: eggert@cs.ucla.edu, 46397@debbugs.gnu.org, craven@gmx.net
> Date: Wed, 17 Mar 2021 16:51:20 -0700
> 
> Thank you for the review Eli.  I've incorporated your feedback in the
> attached patches.

Thanks, we are close.

> I made the warning message even more terse than you suggested because
> before doing so the warnings looked like this:
> 
>     Warning (unlock-file): Error unlocking file Unlocking file:
>     Permission denied, /tmp/inaccessible/foo, ignored [Disable showing]
>     [Disable logging]
> 
> ...which says "unlock file" too many times.  With the current patch it
> is a little bit better:
> 
>     Warning (unlock-file): Unlocking file: Permission denied,
>     /tmp/inaccessible/foo, ignored [Disable showing] [Disable logging]

Fine with me.

> * src/filelock.c (unlock_file_body): New function, do what
> unlock_file() used to.

Please don't use "foo()" to refer to a function 'foo': that looks like
a call of 'foo' with no arguments, which is not what you want.  Our
convention is to use 'foo' instead, quoted 'like this'.

> --- a/doc/lispref/files.texi
> +++ b/doc/lispref/files.texi
> @@ -764,6 +764,8 @@ File Locks
>  if the buffer is modified.  If the buffer is not modified, then
>  the file should not be locked, so this function does nothing.  It also
>  does nothing if the current buffer is not visiting a file, or is not locked.
> +Handles file system errors by calling @code{display-warning} and continuing
   ^^^^^^^
"This function handles ..."

> +** 'unlock-buffer' displays warnings instead of signaling.
> +Instead of signaling 'file-error' conditions for file system level
> +errors, the function now calls 'display-warning' and continues as if
> +the error did not occur.                         ^^^^^^^^^^^^^^^^^^^
   ^^^^^^^^^^^^^^^^^^^^^^^
I'd rephrase "... and otherwise ignores the error".

> +(defun userlock--handle-unlock-error (err)
> +  "Report an error ERR that occurred while unlocking a file."

This will sound better if you rename the argument:

  (defun userlock--handle-unlock-error (error)
    "Report an ERROR that occurred while unlocking a file."