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

[Peter]

The following steps reproduce this:
- Make sure /tmp/tmp does not exist
- Open a buffer /tmp/tmp/foo.txt
- Make some changes to the buffer.
- Do *not* save the buffer or create the directory /tmp/tmp/
- Create /tmp/tmp as a *file* (not a directory)
- Try to kill the buffer.

You will see the following error message:

Unlocking file: Not a directory, /tmp/tmp/foo.txt

I just want to kill the buffer, I don't want to save it.

This is easily rectified by just deleting / moving away /tmp/tmp, but it
seems like this could be resolved to just delete the buffer.

Greetings, Peter



In GNU Emacs 27.1 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.22, cairo 
version 1.17.3)
 of 2020-08-28 built on juergen
Windowing system distributor 'The X.Org Foundation', version 11.0.12010000
System Description: Arch Linux

Recent messages:
<right-margin> <triple-down-mouse-4> is undefined
<right-margin> <triple-mouse-4> is undefined
<right-margin> <triple-down-mouse-4> is undefined
<right-margin> <triple-mouse-4> is undefined
Mark saved where search started
Mark set
Mark saved where search started [2 times]
mouse-2: copy to input; mouse-3: menu [3 times]
Mark set [4 times]
Mark saved where search started [3 times]

Configured using:
 'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
 --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-wide-int
 --with-modules --with-cairo --with-harfbuzz 'CFLAGS=-march=x86-64
 -mtune=generic -O2 -pipe -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2
 LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'

Configured features:
XPM JPEG TIFF GIF PNG RSVG CAIRO SOUND GPM DBUS GSETTINGS GLIB NOTIFY
INOTIFY ACL GNUTLS LIBXML2 FREETYPE HARFBUZZ M17N_FLT LIBOTF ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 XDBE XIM MODULES THREADS LIBSYSTEMD JSON
PDUMPER LCMS2 GMP

Important settings:
  value of $LC_COLLATE: C
  value of $LC_MESSAGES:
  value of $LANG: en_GB.UTF-8
  locale-coding-system: utf-8-unix