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

[Tino Calancha <tino.calancha@gmail.com>]

Allen Li <vianchielfaura@gmail.com> writes:

> Reproduction:
>
> 1. emacs -Q
> 2. F3
> 3. Type some stuff (asdfasdf)
> 4. C-g
> 5. C-u C-u F3
>
> Expected: kmacro definition resumes
>
> Actual: error
>
> Debugger entered--Lisp error: (wrong-type-argument arrayp nil)
>   start-kbd-macro(t t)
Thank you for the report.
I)
  Isn't it this behavior expected?
  C-g ends `start-kbd-macro' before any macro has
  being saved; i.e., `last-kbd-macro' is nil, so we cannot append to it.

  You must have a saved macro to append:
  emacs -Q
  F3
  (insert "a") RET
  F4 ; save it in `last-kbd-macro'

  C-u C-u F3 ; Apped to it.
  (insert "b") RET
  F4 ; Save it.

  F4 ; This insert "ab" in the current buffer.

2)
  Expected or not, i think `kmacro-start-macro' might throw an error
  when the user wants to append and `start-kbd-macro' is nil.

--8<-----------------------------cut here---------------start------------->8---
commit 9c86eed0b015950a4ae06243c5807d9b864eb69f
Author: Tino Calancha <tino.calancha@gmail.com>
Date:   Tue Aug 8 14:14:55 2017 +0900

    Append kbd macro only if last-kbd-macro is non-nil
    
    * lisp/kmacro.el (kmacro-start-macro): Append only if
    last-kbd-macro is non-nil (Bug#28008).

diff --git a/lisp/kmacro.el b/lisp/kmacro.el
index 2db8061fa4..8eff7e5c2e 100644
--- a/lisp/kmacro.el
+++ b/lisp/kmacro.el
@@ -584,7 +584,8 @@ kmacro-start-macro
 	      kmacro-last-counter kmacro-counter
 	      kmacro-counter-format kmacro-default-counter-format
 	      kmacro-counter-format-start kmacro-default-counter-format))
-
+      (when (and append (null last-kbd-macro))
+        (user-error "No kbd macro has been defined"))
       (start-kbd-macro append
 		       (and append
 			    (if kmacro-execute-before-append
--8<-----------------------------cut here---------------end--------------->8---
In GNU Emacs 26.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2017-08-08
Repository revision: c3445aed51944becb3e58f5dace8121c0021f6c7