GNU bug report logs - #65736
30.0.50; Extending the use of format-prompt

Message received at submit <at> debbugs.gnu.org:

Received: (at submit) by debbugs.gnu.org; 4 Sep 2023 16:31:42 +0000
From debbugs-submit-bounces <at> debbugs.gnu.org Mon Sep 04 12:31:42 2023
Received: from localhost ([127.0.0.1]:52417 helo=debbugs.gnu.org)
	by debbugs.gnu.org with esmtp (Exim 4.84_2)
	(envelope-from <debbugs-submit-bounces <at> debbugs.gnu.org>)
	id 1qdCUH-0007P6-E6
	for submit <at> debbugs.gnu.org; Mon, 04 Sep 2023 12:31:42 -0400
Received: from lists.gnu.org ([2001:470:142::17]:44372)
 by debbugs.gnu.org with esmtp (Exim 4.84_2)
 (envelope-from <stephen.berman@HIDDEN>) id 1qdCUB-0007Op-CZ
 for submit <at> debbugs.gnu.org; Mon, 04 Sep 2023 12:31:39 -0400
Received: from eggs.gnu.org ([2001:470:142:3::10])
 by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <stephen.berman@HIDDEN>)
 id 1qdCU6-0007pP-0T
 for bug-gnu-emacs@HIDDEN; Mon, 04 Sep 2023 12:31:30 -0400
Received: from mout.gmx.net ([212.227.17.20])
 by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)
 (Exim 4.90_1) (envelope-from <stephen.berman@HIDDEN>)
 id 1qdCU2-00037Z-Vv
 for bug-gnu-emacs@HIDDEN; Mon, 04 Sep 2023 12:31:29 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net;
 s=s31663417; t=1693845084; x=1694449884; i=stephen.berman@HIDDEN;
 bh=RRfq8xAqfOJVDXDL0/eypltsZFtOho9IPmI7VDW/Akw=;
 h=X-UI-Sender-Class:From:To:Subject:Date;
 b=oh9o1Nnu7Sxuenb1jjgNYO8QsO2XFO6ONNJ1+N2zhhQQgH7XOAYSu129WFecZplBwUTPk5D
 88vVjcqKQd6OAUQwXnaUg/1JzvTLsEjT/lAi1cPRXYJrhi+MmFSFiIddY3vUCRGS7x9S//ckf
 WWb+3KaOlgHzYIBmYH/Nd5NfFz5uTFuLZkf8GFMvHVJf7r8f8lR76qFA5Gep0hvdCKUFponMc
 Ixc5mF1ArmviivIxnTjke5F6sgu0aUS4SyRRXf7+ZmBJcp70Tcn7+EDUxJUXTzAw17OweZhuy
 NrVnFOc4Iqtv6tRd2Z6T22rif9FL5rqgIqNV9T5vLWzfoTfLyJAg==
X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a
Received: from strobelfssd ([94.134.196.62]) by mail.gmx.net (mrgmx104
 [212.227.17.168]) with ESMTPSA (Nemesis) id 1Mn2aN-1ptzmF0SsZ-00k4Ua for
 <bug-gnu-emacs@HIDDEN>; Mon, 04 Sep 2023 18:31:24 +0200
From: Stephen Berman <stephen.berman@HIDDEN>
To: bug-gnu-emacs@HIDDEN
Subject: 30.0.50; Extending the use of format-prompt
Date: Mon, 04 Sep 2023 18:31:23 +0200
Message-ID: <87jzt599yc.fsf@HIDDEN>
User-Agent: Gnus/5.13 (Gnus v5.13)
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="=-=-="
X-Provags-ID: V03:K1:up5I1hfnKR4uF2j1XayZdwvB6JhfyfRgIVuTPRJQniacMmMHyan
 /gz9pFfXlivQzdtXdZz199mETokNw06PARMxsOl6IqYihIhjX0YMmxm/6hL2iPCH1RdXc23
 NtxFSNwxUcWKUIssO21/Uxyy/763VMM91Clx/9m6sqKS0yOe/dFEUuNavtYST3dxjrSDSRM
 eix/mbrxzKugU9i1F9vsg==
X-Spam-Flag: NO
UI-OutboundReport: notjunk:1;M01:P0:+T76QsfvqQQ=;bu7WDe4JITVI3Sv3S38+96Sz3vm
 dGinps+8VghIS6oDHU3XxTvHXaDmWSBIDsBv6kwsKMQhxEdsd6Pt1d+rabS9XWWPQi30qn9b9
 4S81CcbrswwlmDzRFeWi+vrFkPdsa4nlOzt3qPdEoutQ90UwX16nND3gCi3f+P7a8dNQlmWIr
 VXmI+oHPEQ2I4UvunQFdLZrbjNdjq9zhZldirLXdH4+/GrRrU0h839NHU3HN1wDLB19Oo7/BB
 gWSy2mSmISF1QMC6v7AJ6W4jN3snEprUUb+FbOJT6nxPsmZNOSOWBdPztEx3+eOLjFXM5pnWs
 CeTfd2tXBGjL0c5K8BPWvLSvX1O5Sum0jHn4TNVxgeeM9TMVIN3z5qab0/7ekmBkTJT8tT9o3
 xLAOOfp5ZngriBGDpcAZ2WCUEGku5uubx6FPbema72tmeUZPxexb+fqw2FUS3jIlWIyqEW4QO
 N9gTa9SOo9hh5dY2e+STH41dbVvwXn0AJJu9EQn7XNwFv2aK9BFN3rvgdhCF8lcdOfE07a5QH
 qQ/w3z1nDrD/niYJUBkZSPODZUIBCb5GO7XW6ivns7yRVDnjq1wnK5BcRwsE8/6IUmd5GmKwP
 iJOWFBf2ctZJPFXhFdTswiLlyUmfeJjQH21GDzQBayOhsnKYGF9l7YQuf3+9A32QHePLZgmLL
 CoE1gc2SRK2g/bCrxO08ljYo5GgOtpUCyLxKsZEJjESvrPracA+RZHeX03UXuuefZZ6diStfj
 zwYEnCIg+U5Np7HL+qnTk9QoxmshFafONEbkkEkJPZfsLvQyVsVvXi35HVhm0nn/Ec+3J9CtC
 rScIQmY4HElrVo8oHeyjOVt5i4oz1FzUWfsj+aGzu5fNFiDs3X52cVlWutz23YigkJi6EBEgV
 woweOSlXNKijmY4xGtcinuIhKzVXF7S3P0wa5IFmB51AsdnQplBbbFTTGC/RnTmkVCU0ntZsq
 JtKzYnfZ+OF+qQ1eldyZC8KZn7I=
Received-SPF: pass client-ip=212.227.17.20;
 envelope-from=stephen.berman@HIDDEN; helo=mout.gmx.net
X-Spam_score_int: -27
X-Spam_score: -2.8
X-Spam_bar: --
X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1,
 DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001,
 RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001,
 SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no
X-Spam_action: no action
X-Spam-Score: 1.0 (+)
X-Debbugs-Envelope-To: submit
X-BeenThere: debbugs-submit <at> debbugs.gnu.org
X-Mailman-Version: 2.1.18
Precedence: list
List-Id: <debbugs-submit.debbugs.gnu.org>
List-Unsubscribe: <https://debbugs.gnu.org/cgi-bin/mailman/options/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=unsubscribe>
List-Archive: <https://debbugs.gnu.org/cgi-bin/mailman/private/debbugs-submit/>
List-Post: <mailto:debbugs-submit <at> debbugs.gnu.org>
List-Help: <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=help>
List-Subscribe: <https://debbugs.gnu.org/cgi-bin/mailman/listinfo/debbugs-submit>, 
 <mailto:debbugs-submit-request <at> debbugs.gnu.org?subject=subscribe>
Errors-To: debbugs-submit-bounces <at> debbugs.gnu.org
Sender: "Debbugs-submit" <debbugs-submit-bounces <at> debbugs.gnu.org>
X-Spam-Score: -0.0 (/)

--=-=-=
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

0. emacs -Q
1. Invoke read-buffer with a prompt containg grave-style quoting and
   with no default buffer argument, e.g.:
   M-: (read-buffer "Enter `buffer': ")
=3D> This displays the prompt in the minibuffer with grave-style quoting,
   i.e. as it appears in the invocation.
2. Repeat step 1 but add a default buffer argument, e.g.:
   M-: (read-buffer "Enter `buffer': " "*scratch*")
=3D> This displays the prompt in the minibuffer with curve-style quoting:
   Enter =E2=80=98buffer=E2=80=99 (default *scratch*):=20=20

The different appearances of the prompt with and without the presence of
a default argument is due to commit 50512e36c7, which passes the prompt
string to format-prompt when read-buffer has a non-nil default argument
DEF, but not when DEF is nil.  (The purpose of that commit was to
replace occurrences of prompts containing the string "(default %s)" by
invocations of the then recently introduced function format-prompt; the
fact that this function also calls substitute-command-keys was not a
concern for that commit and its effect was presumably for that reason
overlooked.)

I think the simplest fix is to pass PROMPT to format-prompt regardless
of the presence of a default argument of read-buffer, as in the first
attached patch.

But having substitute-command-keys always apply to the prompt string of
read-buffer raises the question whether it should apply more generally
to prompt strings.  In fact, commit 50512e36c7 did change numerous
mostly mode-specific prompts in several Lisp libraries to pass the
prompt to format-prompt, but in almost all cases those prompts are fixed
strings where applying substitute-command-keys makes no difference.  But
with read-buffer the prompt string is provided by the caller, so its
appearance could be affected by substitute-command-keys.

By default, read-buffer calls (in C) completing-read, which by default
calls read-from-minibuffer, and indeed most, if not all, other functions
that prompt for minibuffer input end up calling read-from-minibuffer.
So passing the prompt string to format-prompt in read-from-minibuffer,
as in the second attached patch (which should be applied instead of the
first patch), would achieve a higher degree of consistency and
simplicity in Emacs in the handling of prompts for minibuffer input, at
least by default.  (With functions that accept a user-defined function,
like read-buffer-function with read-buffer, it would be up to the user
to decide whether or not to use format-prompt, if the function does not
invoke read-from-minibuffer.)

If this change (the second patch) is accepted, it will probably require
adjustments in the Emacs code base, e.g. to avoid double invocations of
format-prompt.  This would partly undo the changes made in 50512e36c7.
I'd be willing to make the needed adjustments in Emacs.

Steve Berman


--=-=-=
Content-Type: text/x-patch
Content-Disposition: attachment
Content-Description: read-buffer patch
Content-Transfer-Encoding: quoted-printable

diff --git a/src/minibuf.c b/src/minibuf.c
index 58adde1bf66..a1cbf4747f5 100644
=2D-- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -1502,34 +1502,30 @@ DEFUN ("read-buffer", Fread_buffer, Sread_buffer, =
1, 4, 0,
   specbind (Qcompletion_ignore_case,
 	    read_buffer_completion_ignore_case ? Qt : Qnil);

-  if (NILP (Vread_buffer_function))
-    {
-      if (!NILP (def))
-	{
-	  /* A default value was provided: we must change PROMPT,
-	     editing the default value in before the colon.  To achieve
-	     this, we replace PROMPT with a substring that doesn't
-	     contain the terminal space and colon (if present).  They
-	     are then added back using Fformat.  */
+  /* For backward compatibility we accept prompt strings ending with a
+     colon and a space, but we have to delete them, if present, before
+     passing PROMPT to `format-prompt', which automatically appends
+     these characters to PROMPT.  */

-	  if (STRINGP (prompt))
-	    {
-	      s =3D SSDATA (prompt);
-	      len =3D SBYTES (prompt);
-	      if (len >=3D 2 && s[len - 2] =3D=3D ':' && s[len - 1] =3D=3D ' ')
-		len =3D len - 2;
-	      else if (len >=3D 1 && (s[len - 1] =3D=3D ':' || s[len - 1] =3D=3D=
 ' '))
-		len--;
-
-	      prompt =3D make_specified_string (s, -1, len,
-					      STRING_MULTIBYTE (prompt));
-	    }
+  if (STRINGP (prompt))
+    {
+      s =3D SSDATA (prompt);
+      len =3D SBYTES (prompt);
+      if (len >=3D 2 && s[len - 2] =3D=3D ':' && s[len - 1] =3D=3D ' ')
+	len =3D len - 2;
+      else if (len >=3D 1 && (s[len - 1] =3D=3D ':' || s[len - 1] =3D=3D =
' '))
+	len--;
+
+      prompt =3D make_specified_string (s, -1, len,
+				      STRING_MULTIBYTE (prompt));
+    }

-	  prompt =3D CALLN (Ffuncall, intern("format-prompt"),
-			  prompt,
-			  CONSP (def) ? XCAR (def) : def);
-	}
+  prompt =3D CALLN (Ffuncall, intern("format-prompt"),
+		  prompt,
+		  CONSP (def) ? XCAR (def) : def);

+  if (NILP (Vread_buffer_function))
+    {
       result =3D Fcompleting_read (prompt, intern ("internal-complete-buf=
fer"),
 				 predicate, require_match, Qnil,
 				 Qbuffer_name_history, def, Qnil);

--=-=-=
Content-Type: text/x-patch
Content-Disposition: attachment
Content-Description: read-from-minibuffer patch
Content-Transfer-Encoding: quoted-printable

diff --git a/src/minibuf.c b/src/minibuf.c
index 58adde1bf66..4318cab04cb 100644
=2D-- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -1343,10 +1343,34 @@ DEFUN ("read-from-minibuffer", Fread_from_minibuff=
er,
   (Lisp_Object prompt, Lisp_Object initial_contents, Lisp_Object keymap, =
Lisp_Object read, Lisp_Object hist, Lisp_Object default_value, Lisp_Object=
 inherit_input_method)
 {
   Lisp_Object histvar, histpos, val;
+  char *s;
+  ptrdiff_t len;

   barf_if_interaction_inhibited ();

   CHECK_STRING (prompt);
+
+  /* For backward compatibility we accept prompt strings ending with a
+     colon and a space, but we have to delete them, if present, before
+     passing PROMPT to `format-prompt', which automatically appends
+     these characters to PROMPT.  */
+
+  if (STRINGP (prompt))
+    {
+      s =3D SSDATA (prompt);
+      len =3D SBYTES (prompt);
+      if (len >=3D 2 && s[len - 2] =3D=3D ':' && s[len - 1] =3D=3D ' ')
+	len =3D len - 2;
+      else if (len >=3D 1 && (s[len - 1] =3D=3D ':' || s[len - 1] =3D=3D =
' '))
+	len--;
+
+      prompt =3D make_specified_string (s, -1, len,
+				      STRING_MULTIBYTE (prompt));
+    }
+
+  prompt =3D CALLN (Ffuncall, intern("format-prompt"), prompt,
+		  CONSP (default_value) ? XCAR (default_value) : default_value);
+
   if (NILP (keymap))
     keymap =3D Vminibuffer_local_map;
   else
@@ -1473,8 +1497,7 @@ DEFUN ("read-variable", Fread_variable, Sread_variab=
le, 1, 2, 0,

 DEFUN ("read-buffer", Fread_buffer, Sread_buffer, 1, 4, 0,
        doc: /* Read the name of a buffer and return it as a string.
-Prompt with PROMPT, which should be a string ending with a colon and a sp=
ace.
-Provides completion on buffer names the user types.
+Prompt with string PROMPT.  Provides completion on buffer names the user =
types.
 Optional second arg DEF is value to return if user enters an empty line,
  instead of that empty string.
  If DEF is a list of default values, return its first element.
@@ -1492,8 +1515,6 @@ DEFUN ("read-buffer", Fread_buffer, Sread_buffer, 1,=
 4, 0,
    Lisp_Object predicate)
 {
   Lisp_Object result;
-  char *s;
-  ptrdiff_t len;
   specpdl_ref count =3D SPECPDL_INDEX ();

   if (BUFFERP (def))
@@ -1503,37 +1524,9 @@ DEFUN ("read-buffer", Fread_buffer, Sread_buffer, 1=
, 4, 0,
 	    read_buffer_completion_ignore_case ? Qt : Qnil);

   if (NILP (Vread_buffer_function))
-    {
-      if (!NILP (def))
-	{
-	  /* A default value was provided: we must change PROMPT,
-	     editing the default value in before the colon.  To achieve
-	     this, we replace PROMPT with a substring that doesn't
-	     contain the terminal space and colon (if present).  They
-	     are then added back using Fformat.  */
-
-	  if (STRINGP (prompt))
-	    {
-	      s =3D SSDATA (prompt);
-	      len =3D SBYTES (prompt);
-	      if (len >=3D 2 && s[len - 2] =3D=3D ':' && s[len - 1] =3D=3D ' ')
-		len =3D len - 2;
-	      else if (len >=3D 1 && (s[len - 1] =3D=3D ':' || s[len - 1] =3D=3D=
 ' '))
-		len--;
-
-	      prompt =3D make_specified_string (s, -1, len,
-					      STRING_MULTIBYTE (prompt));
-	    }
-
-	  prompt =3D CALLN (Ffuncall, intern("format-prompt"),
-			  prompt,
-			  CONSP (def) ? XCAR (def) : def);
-	}
-
-      result =3D Fcompleting_read (prompt, intern ("internal-complete-buf=
fer"),
-				 predicate, require_match, Qnil,
-				 Qbuffer_name_history, def, Qnil);
-    }
+    result =3D Fcompleting_read (prompt, intern ("internal-complete-buffe=
r"),
+			       predicate, require_match, Qnil,
+			       Qbuffer_name_history, def, Qnil);
   else
     result =3D (NILP (predicate)
 	      /* Partial backward compatibility for older read_buffer_functions
@@ -1978,7 +1971,7 @@ DEFUN ("all-completions", Fall_completions, Sall_com=
pletions, 2, 4, 0,
 =0C
 DEFUN ("completing-read", Fcompleting_read, Scompleting_read, 2, 8, 0,
        doc: /* Read a string in the minibuffer, with completion.
-PROMPT is a string to prompt with; normally it ends in a colon and a spac=
e.
+PROMPT is a string to prompt with.
 COLLECTION can be a list of strings, an alist, an obarray or a hash table=
.
 COLLECTION can also be a function to do the completion itself.
 PREDICATE limits completion to a subset of COLLECTION.

--=-=-=--