bug#48603: 27.2; [PATCH] Quit minibuffers without aborting kmacros

[miha--- via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

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Rationale: a user wants to copy a command from command history without
executing it. Or user wants to complete a file name in C-x C-f and copy
it without finding the file. I believe this should be possible in
keyboard macros.


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From 5513841b55e47f05f3e049ffcb71a0fc56287fbc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miha=20Rihtar=C5=A1i=C4=8D?= <miha@kamnitnik.top>
Date: Sun, 23 May 2021 16:08:43 +0200
Subject: [PATCH] Quit minibuffers without aborting kmacros

* src/data.c (syms_of_data): New error symbol `lite-quit'

* src/keyboard.c (recursive_edit_1): Implement throwing of function
values to `exit`.  In that case, the function will be called without
arguments before returning from the command loop.
(cmd_error):
(Fcommand_error_default_function): Do not abort keyboard macro
execution if lite-quit is signaled.
(command_loop_2): New argument HANDLERS.

* src/macros.c (Fexecute_kbd_macro): Use command_loop_2 instead of
command_loop_1.

* doc/lispref/commands.texi (Quitting): Document `lite-quit'
(Recursive Editing): Document throwing of function values to `exit'.

* doc/lispref/errors.texi (Standard Errors): Document `lite-quit'

* lisp/minibuffer.el (lite-quit-recursive-edit): New function.

* src/minibuf.c (Fabort_minibuffers): Use it.

* lisp/simple.el (minibuffer-error-function): Do not abort keyboard
macro execution if is lite-quit is signaled.
---
 doc/lispref/commands.texi | 14 +++++++++---
 doc/lispref/errors.texi   |  9 ++++++--
 lisp/minibuffer.el        |  9 ++++++++
 lisp/simple.el            |  6 ++++--
 src/data.c                |  2 ++
 src/keyboard.c            | 45 ++++++++++++++++++++++++++++-----------
 src/lisp.h                |  2 +-
 src/macros.c              |  2 +-
 src/minibuf.c             |  2 +-
 9 files changed, 69 insertions(+), 22 deletions(-)

diff --git a/doc/lispref/commands.texi b/doc/lispref/commands.texi
index 8199ece110..a0b99ed144 100644
--- a/doc/lispref/commands.texi
+++ b/doc/lispref/commands.texi
@@ -3378,6 +3378,12 @@ Quitting
 in @ref{Errors}.)
 @end deffn
 
+  To quit without aborting keyboard macro definition or execution, you
+can signal the @code{lite-quit} condition.  This has almost the same
+effect as the @code{quit} condition except that the error handling in
+the command loop handles it without breaking keyboard macro definition
+or execution.
+
   You can specify a character other than @kbd{C-g} to use for quitting.
 See the function @code{set-input-mode} in @ref{Input Modes}.
 
@@ -3562,12 +3568,14 @@ Recursive Editing
 @code{recursive-edit}.  This function contains the command loop; it also
 contains a call to @code{catch} with tag @code{exit}, which makes it
 possible to exit the recursive editing level by throwing to @code{exit}
-(@pxref{Catch and Throw}).  If you throw a value other than @code{t},
-then @code{recursive-edit} returns normally to the function that called
-it.  The command @kbd{C-M-c} (@code{exit-recursive-edit}) does this.
+(@pxref{Catch and Throw}).  If you throw a @code{nil} value, then
+@code{recursive-edit} returns normally to the function that called it.
+The command @kbd{C-M-c} (@code{exit-recursive-edit}) does this.
 Throwing a @code{t} value causes @code{recursive-edit} to quit, so that
 control returns to the command loop one level up.  This is called
 @dfn{aborting}, and is done by @kbd{C-]} (@code{abort-recursive-edit}).
+You can also throw a function value.  In that case,
+@code{recursive-edit} will call it without arguments before returning.
 
   Most applications should not use recursive editing, except as part of
 using the minibuffer.  Usually it is more convenient for the user if you
diff --git a/doc/lispref/errors.texi b/doc/lispref/errors.texi
index fb393b951f..a45489db8e 100644
--- a/doc/lispref/errors.texi
+++ b/doc/lispref/errors.texi
@@ -20,8 +20,9 @@ Standard Errors
 we do not say here that a certain error symbol has additional error
 conditions, that means it has none.
 
-  As a special exception, the error symbol @code{quit} does not have the
-condition @code{error}, because quitting is not considered an error.
+  As a special exception, the error symbols @code{quit} and
+@code{lite-quit} don't have the condition @code{error}, because quitting
+is not considered an error.
 
   Most of these error symbols are defined in C (mainly @file{data.c}),
 but some are defined in Lisp.  For example, the file @file{userlock.el}
@@ -40,6 +41,10 @@ Standard Errors
 @item quit
 The message is @samp{Quit}.  @xref{Quitting}.
 
+@item lite-quit
+The message is @samp{Quit}.  This is a subcategory of @code{quit}.
+@xref{Quitting}.
+
 @item args-out-of-range
 The message is @samp{Args out of range}.  This happens when trying to
 access an element beyond the range of a sequence, buffer, or other
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index e04f1040b3..d1b88b0355 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -2318,6 +2318,15 @@ exit-minibuffer
   (setq deactivate-mark nil)
   (throw 'exit nil))
 
+(defun lite-quit-recursive-edit ()
+  "Quit the command that requested this recursive edit wihtout error.
+Like `abort-recursive-edit' wihtout aborting keyboard macro
+execution."
+  ;; See Info node `(elisp)Recursive Editing' for an explanation of
+  ;; throwing a function to `exit'.
+  (throw 'exit (lambda ()
+                 (signal 'lite-quit nil))))
+
 (defun self-insert-and-exit ()
   "Terminate minibuffer input."
   (interactive)
diff --git a/lisp/simple.el b/lisp/simple.el
index 2a90a07631..191c9d482d 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -2854,8 +2854,10 @@ minibuffer-error-function
 The same as `command-error-default-function' but display error messages
 at the end of the minibuffer using `minibuffer-message' to not obscure
 the minibuffer contents."
-  (discard-input)
-  (ding)
+  (if (memq 'lite-quit (get (car data) 'error-conditions))
+      (ding t)
+    (discard-input)
+    (ding))
   (let ((string (error-message-string data)))
     ;; If we know from where the error was signaled, show it in
     ;; *Messages*.
diff --git a/src/data.c b/src/data.c
index d547f5da5e..315d43942c 100644
--- a/src/data.c
+++ b/src/data.c
@@ -3899,6 +3899,7 @@ syms_of_data (void)
   DEFSYM (Qerror, "error");
   DEFSYM (Quser_error, "user-error");
   DEFSYM (Qquit, "quit");
+  DEFSYM (Qlite_quit, "lite-quit");
   DEFSYM (Qwrong_length_argument, "wrong-length-argument");
   DEFSYM (Qwrong_type_argument, "wrong-type-argument");
   DEFSYM (Qargs_out_of_range, "args-out-of-range");
@@ -3971,6 +3972,7 @@ #define PUT_ERROR(sym, tail, msg)			\
   Fput (sym, Qerror_message, build_pure_c_string (msg))
 
   PUT_ERROR (Qquit, Qnil, "Quit");
+  PUT_ERROR (Qlite_quit, pure_cons (Qquit, Qnil), "Quit");
 
   PUT_ERROR (Quser_error, error_tail, "");
   PUT_ERROR (Qwrong_length_argument, error_tail, "Wrong length argument");
diff --git a/src/keyboard.c b/src/keyboard.c
index 47b5e59024..10e1386023 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -725,6 +725,9 @@ recursive_edit_1 (void)
   if (STRINGP (val))
     xsignal1 (Qerror, val);
 
+  if (FUNCTIONP (val))
+    call0 (val);
+
   return unbind_to (count, Qnil);
 }
 
@@ -921,6 +924,7 @@ restore_kboard_configuration (int was_locked)
 cmd_error (Lisp_Object data)
 {
   Lisp_Object old_level, old_length;
+  Lisp_Object conditions;
   char macroerror[sizeof "After..kbd macro iterations: "
 		  + INT_STRLEN_BOUND (EMACS_INT)];
 
@@ -940,10 +944,15 @@ cmd_error (Lisp_Object data)
   else
     *macroerror = 0;
 
+  conditions = Fget (XCAR (data), Qerror_conditions);
+  if (NILP (Fmemq (Qlite_quit, conditions)))
+    {
+      Vexecuting_kbd_macro = Qnil;
+      executing_kbd_macro = Qnil;
+    }
+
   Vstandard_output = Qt;
   Vstandard_input = Qt;
-  Vexecuting_kbd_macro = Qnil;
-  executing_kbd_macro = Qnil;
   kset_prefix_arg (current_kboard, Qnil);
   kset_last_prefix_arg (current_kboard, Qnil);
   cancel_echoing ();
@@ -998,6 +1007,7 @@ DEFUN ("command-error-default-function", Fcommand_error_default_function,
   (Lisp_Object data, Lisp_Object context, Lisp_Object signal)
 {
   struct frame *sf = SELECTED_FRAME ();
+  Lisp_Object conditions;
 
   CHECK_STRING (context);
 
@@ -1024,17 +1034,27 @@ DEFUN ("command-error-default-function", Fcommand_error_default_function,
     }
   else
     {
+      conditions = Fget (XCAR (data), Qerror_conditions);
+
       clear_message (1, 0);
-      Fdiscard_input ();
       message_log_maybe_newline ();
-      bitch_at_user ();
+
+      if (!NILP (Fmemq (Qlite_quit, conditions)))
+	{
+	  Fding (Qt);
+	}
+      else
+	{
+	  Fdiscard_input ();
+	  bitch_at_user ();
+	}
 
       print_error_message (data, Qt, SSDATA (context), signal);
     }
   return Qnil;
 }
 
-static Lisp_Object command_loop_2 (Lisp_Object);
+static Lisp_Object command_loop_1 (void);
 static Lisp_Object top_level_1 (Lisp_Object);
 
 /* Entry to editor-command-loop.
@@ -1062,7 +1082,7 @@ command_loop (void)
   if (command_loop_level > 0 || minibuf_level > 0)
     {
       Lisp_Object val;
-      val = internal_catch (Qexit, command_loop_2, Qnil);
+      val = internal_catch (Qexit, command_loop_2, Qerror);
       executing_kbd_macro = Qnil;
       return val;
     }
@@ -1070,7 +1090,7 @@ command_loop (void)
     while (1)
       {
 	internal_catch (Qtop_level, top_level_1, Qnil);
-	internal_catch (Qtop_level, command_loop_2, Qnil);
+	internal_catch (Qtop_level, command_loop_2, Qerror);
 	executing_kbd_macro = Qnil;
 
 	/* End of file in -batch run causes exit here.  */
@@ -1083,15 +1103,16 @@ command_loop (void)
    editing loop, and reenter the editing loop.
    When there is an error, cmd_error runs and returns a non-nil
    value to us.  A value of nil means that command_loop_1 itself
-   returned due to end of file (or end of kbd macro).  */
+   returned due to end of file (or end of kbd macro).  HANDLERS is a
+   list of condition names, passed to internal_condition_case.  */
 
-static Lisp_Object
-command_loop_2 (Lisp_Object ignore)
+Lisp_Object
+command_loop_2 (Lisp_Object handlers)
 {
   register Lisp_Object val;
 
   do
-    val = internal_condition_case (command_loop_1, Qerror, cmd_error);
+    val = internal_condition_case (command_loop_1, handlers, cmd_error);
   while (!NILP (val));
 
   return Qnil;
@@ -1234,7 +1255,7 @@ some_mouse_moved (void)
                               bool, bool, bool, bool);
 static void adjust_point_for_property (ptrdiff_t, bool);
 
-Lisp_Object
+static Lisp_Object
 command_loop_1 (void)
 {
   modiff_count prev_modiff = 0;
diff --git a/src/lisp.h b/src/lisp.h
index 91b7a89d0f..a30d7b861d 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -4417,7 +4417,7 @@ fast_string_match_ignore_case (Lisp_Object regexp, Lisp_Object string)
 extern bool detect_input_pending_run_timers (bool);
 extern void safe_run_hooks (Lisp_Object);
 extern void cmd_error_internal (Lisp_Object, const char *);
-extern Lisp_Object command_loop_1 (void);
+extern Lisp_Object command_loop_2 (Lisp_Object);
 extern Lisp_Object read_menu_command (void);
 extern Lisp_Object recursive_edit_1 (void);
 extern void record_auto_save (void);
diff --git a/src/macros.c b/src/macros.c
index 60d0766a75..53ad727a5b 100644
--- a/src/macros.c
+++ b/src/macros.c
@@ -324,7 +324,7 @@ DEFUN ("execute-kbd-macro", Fexecute_kbd_macro, Sexecute_kbd_macro, 1, 3, 0,
 	    break;
 	}
 
-      command_loop_1 ();
+      command_loop_2 (list1 (Qlite_quit));
 
       executing_kbd_macro_iterations = ++success_count;
 
diff --git a/src/minibuf.c b/src/minibuf.c
index cffb7fe787..9237cbe2b6 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -496,7 +496,7 @@ DEFUN ("abort-minibuffers", Fabort_minibuffers, Sabort_minibuffers, 0, 0, "",
 	}
     }
   else
-    Fthrow (Qexit, Qt);
+    CALLN (Ffuncall, intern ("lite-quit-recursive-edit"));
   return Qnil;
 }
 
-- 
2.31.1