From: Stefan Kangas <stefankangas@gmail.com>
Date: Sat, 8 Mar 2025 17:24:26 +0000 (+0100)
Subject: Make second arg to defvar-local optional
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=411775805e0ae10038c3e24ff9271f06f1f961ac;p=emacs.git

Make second arg to defvar-local optional

This change allows declaring a variable both special
and buffer-local like so:

    (defvar-local foo)

* lisp/subr.el (defvar-local): Make second argument optional.
* test/lisp/subr-tests.el (subr-test-defvar-local): New test.
* doc/lispref/variables.texi (Creating Buffer-Local): Document above change.
* etc/NEWS:

* lisp/mb-depth.el (minibuffer-depth-overlay):
* lisp/minibuf-eldef.el (minibuf-eldef-initial-input)
(minibuf-eldef-initial-buffer-length)
(minibuf-eldef-showing-default-in-prompt, minibuf-eldef-overlay):
* lisp/misc.el (list-dynamic-libraries--loaded-only-p):
* lisp/simple.el (minibuffer-history-isearch-message-overlay): Use
above new one-argument form of 'defvar-local'.

(cherry picked from commit ce03bf252ae9bff28a6def163cb3f4fa102e691a)
---

diff --git a/doc/lispref/variables.texi b/doc/lispref/variables.texi
index 6f2dbd6b3ec..daece2d3a79 100644
--- a/doc/lispref/variables.texi
+++ b/doc/lispref/variables.texi
@@ -1649,7 +1649,7 @@ on having separate values in separate buffers, then using
 @code{make-variable-buffer-local} can be the best solution.
 @end deffn
 
-@defmac defvar-local variable value &optional docstring
+@defmac defvar-local variable &optional value docstring
 This macro defines @var{variable} as a variable with initial value
 @var{value} and @var{docstring}, and marks it as automatically
 buffer-local.  It is equivalent to calling @code{defvar} followed by
diff --git a/lisp/mb-depth.el b/lisp/mb-depth.el
index 82b1583bd11..87a386207e7 100644
--- a/lisp/mb-depth.el
+++ b/lisp/mb-depth.el
@@ -49,8 +49,7 @@ the `minibuffer-depth-indicator' face."
 ;; An overlay covering the prompt.  This is a buffer-local variable in
 ;; each affected minibuffer.
 ;;
-(defvar minibuffer-depth-overlay)
-(make-variable-buffer-local 'minibuffer-depth-overlay)
+(defvar-local minibuffer-depth-overlay)
 
 ;; This function goes on minibuffer-setup-hook
 (defun minibuffer-depth-setup ()
diff --git a/lisp/misc.el b/lisp/misc.el
index c8fb37cef6a..7008940288f 100644
--- a/lisp/misc.el
+++ b/lisp/misc.el
@@ -261,8 +261,7 @@ variation of `C-x M-c M-butterfly' from url `https://xkcd.com/378/'."
 ;; A command to list dynamically loaded libraries.  This useful in
 ;; environments where dynamic-library-alist is used, i.e., Windows
 
-(defvar list-dynamic-libraries--loaded-only-p)
-(make-variable-buffer-local 'list-dynamic-libraries--loaded-only-p)
+(defvar-local list-dynamic-libraries--loaded-only-p)
 
 (defun list-dynamic-libraries--loaded (from)
   "Compute the \"Loaded from\" column.
diff --git a/lisp/simple.el b/lisp/simple.el
index 6dc693ef246..7ecb0f70859 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3101,8 +3101,7 @@ by the new completion."
 ;; isearch minibuffer history
 (add-hook 'minibuffer-setup-hook 'minibuffer-history-isearch-setup)
 
-(defvar minibuffer-history-isearch-message-overlay)
-(make-variable-buffer-local 'minibuffer-history-isearch-message-overlay)
+(defvar-local minibuffer-history-isearch-message-overlay)
 
 (defun minibuffer-history-isearch-setup ()
   "Set up a minibuffer for using isearch to search the minibuffer history.
diff --git a/lisp/subr.el b/lisp/subr.el
index 89066b4b2c2..a9474861c13 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -226,14 +226,20 @@ If FUNS is empty, expand to `identity'."
                (t `(funcall ,fun ,arg)))))
       `(lambda (,x) ,arg)))))
 
-(defmacro defvar-local (var val &optional docstring)
-  "Define VAR as a buffer-local variable with default value VAL.
+(defmacro defvar-local (symbol &rest args)
+  "Define VAR as a buffer-local variable with default value VALUE.
 Like `defvar' but additionally marks the variable as being automatically
-buffer-local wherever it is set."
+buffer-local wherever it is set.
+\n(fn symbol &optional value docstring)"
   (declare (debug defvar) (doc-string 3) (indent 2))
   ;; Can't use backquote here, it's too early in the bootstrap.
-  (list 'progn (list 'defvar var val docstring)
-        (list 'make-variable-buffer-local (list 'quote var))))
+  (let ((value (car-safe args))
+        (docstring (car-safe (cdr-safe args))))
+    (list 'progn
+          (if (zerop (length args))
+              (list 'defvar symbol)
+            (list 'defvar symbol value docstring))
+          (list 'make-variable-buffer-local (list 'quote symbol)))))
 
 (defun buffer-local-boundp (symbol buffer)
   "Return non-nil if SYMBOL is bound in BUFFER.
diff --git a/test/lisp/subr-tests.el b/test/lisp/subr-tests.el
index c2f64867d90..86538ed1431 100644
--- a/test/lisp/subr-tests.el
+++ b/test/lisp/subr-tests.el
@@ -30,6 +30,16 @@
 (require 'ert-x)
 (eval-when-compile (require 'cl-lib))
 
+(defvar-local subr-tests--local-var1)
+(defvar-local subr-tests--local-var2 'hello)
+(defvar-local subr-tests--local-var3 nil "Doc.")
+(ert-deftest subr-test-defvar-local ()
+  (should (local-variable-if-set-p 'subr-tests--local-var1))
+  (should (local-variable-if-set-p 'subr-tests--local-var2))
+  (should (eq subr-tests--local-var2 'hello))
+  (should (local-variable-if-set-p 'subr-tests--local-var3))
+  (should (get 'subr-tests--local-var3 'variable-documentation)))
+
 (ert-deftest subr-test-apply-partially ()
   (should (functionp (apply-partially #'identity)))
   (should (functionp (apply-partially #'list 1 2 3)))