bug#28258: 26.0.50; [PATCH] Let file-name-base succeed when buffer-file-name is nil

[Mohammed Sadiq]

Let file-name-base succeed when buffer-file-name is nil.

Hi. This is my first patch to GNU Emacs. Please let me know if it is
sensible or not.

Thanks

>From efb4f12c9083ad3930eaf5da8929d4e6b33609eb Mon Sep 17 00:00:00 2001
From: "Mohammed Sadik P. K" <sadiq@sadiqpk.org>
Date: Mon, 28 Aug 2017 07:34:25 +0530
Subject: [PATCH] Let file-name-base succeed when buffer-file-name is nil

FILENAME is an optional argument for file-name-base.  So it shouldn't
fail when no filename is associated with current buffer.

* lisp/files.el (file-name-base): Don't fail when buffer-file-name
is nil.
---
 lisp/files.el | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lisp/files.el b/lisp/files.el
index 872fc46e87..d75d402545 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -4467,8 +4467,9 @@ file-name-extension
 (defun file-name-base (&optional filename)
   "Return the base name of the FILENAME: no directory, no extension.
 FILENAME defaults to `buffer-file-name'."
-  (file-name-sans-extension
-   (file-name-nondirectory (or filename (buffer-file-name)))))
+  (let ((filename (or filename (buffer-file-name))))
+    (and filename
+        (file-name-sans-extension (file-name-nondirectory filename)))))
 
 (defcustom make-backup-file-name-function
   #'make-backup-file-name--default-function
-- 
2.11.0



In GNU Emacs 26.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2017-08-27 built on rose
Repository revision: 853ed4533bbddf16c50ad12ed1db70fa252715fb
Windowing system distributor 'The X.Org Foundation', version 11.0.11902000
System Description:     Debian GNU/Linux 9.1 (stretch)

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
Making completion list...
delete-backward-char: Text is read-only

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11 LIBSYSTEMD

Important settings:
  value of $LC_MONETARY: en_GB.UTF-8
  value of $LC_NUMERIC: en_GB.UTF-8
  value of $LC_TIME: en_GB.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Lisp Interaction

Minor modes in effect:
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  global-eldoc-mode: t
  eldoc-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Load-path shadows:
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Features:
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rfc2045 ietf-drums mm-util mail-prsvr mail-utils elec-pair time-date
mule-util tooltip eldoc electric uniquify ediff-hook vc-hooks
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custom widget hashtable-print-readable backquote dbusbind inotify
dynamic-setting system-font-setting font-render-setting move-toolbar gtk
x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 95499 5650)
 (symbols 48 20292 1)
 (miscs 40 43 93)
 (strings 32 28804 1235)
 (string-bytes 1 763186)
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