bug#28008: 25.2; Resume kmacro definition errors C-u C-u <F3>

[Allen Li <vianchielfaura@gmail.com>]

On Mon, Sep 18, 2017 at 1:02 PM, Allen Li <vianchielfaura@gmail.com> wrote:
> On Fri, Aug 11, 2017 at 6:17 AM, Tino Calancha <tino.calancha@gmail.com> wrote:
>>
>> On Fri, 11 Aug 2017, Eli Zaretskii wrote:
>>> All these low-level changes just to support an obscure use case?  Is
>>> really worth the risk to break macros to cater to that?
>>
>> That depends of how often someone uses kbd macros.  I rarely use them, but
>> the people using them frequently might suffer D.2 from time to time.
>>
>> Actually, the patch#1 is quite short: i included a docstring fix from
>> the patch#2 by mistake.
>> The C code changes in patch#1 are just:
>>  3 files changed, 41 insertions(+), 2 deletions(-)
>
> I had to change a c to Qc in macros.c to get patch 1 to compile.
> However, it does not seem to fix case D.2.  I don't think this was
> made explicit, but case D.2 applies to all undefined keybindings, so
> for example C-x C-g, but also C-c z.
>
> We should at least fix the behavior for case D.2  The more invasive
> patch 2 can be discussed later, but Emacs shouldn't just discard the
> entire recorded macro on an undefined key press.  This makes me
> nervous whenever I use kmacros.

Actually, to fix case D.2 (where undefined keys exit kmacro definition
without saving), all that is needed is a short Emacs Lisp change.
This keeps the behavior of a bare C-g keyboard-abort of not saving the
kmacro.

[PATCH] Make undefined keys exit and save kmacro definition

* lisp/subr.el (undefined): Error out of kmacro definition.
---
 lisp/subr.el | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lisp/subr.el b/lisp/subr.el
index 79ae1f4830..f0c4e2969d 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -785,8 +785,9 @@ undefined
   "Beep to tell the user this binding is undefined."
   (interactive)
   (ding)
-  (message "%s is undefined" (key-description (this-single-command-keys)))
-  (setq defining-kbd-macro nil)
+  (if defining-kbd-macro
+      (error "%s is undefined" (key-description (this-single-command-keys)))
+    (message "%s is undefined" (key-description (this-single-command-keys))))
   (force-mode-line-update)
   ;; If this is a down-mouse event, don't reset prefix-arg;
   ;; pass it to the command run by the up event.
-- 
2.14.1