bug#47454: plist-put should have a version which accepts multiple properties

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

forcemerge 47454 49053
close 47454 49053
thanks

Stefan Monnier [2021-06-15 08:48:25] wrote:

> Juri Linkov [2021-06-15 00:53:54] wrote:
>
>>> (setf (seq-elt plist ...))
>>>
>>> may help with that, though.
>>
>> BTW, often after pulling from master and recompiling,
>> Emacs fails to start with such errors:
>>
>> Debugger entered--Lisp error: (error "(setf seq-elt) is already defined as
>> something else than a generic function")
>>   error("%s is already defined as something else than a generic function" \(setf\ seq-elt\))
>>   cl-generic-ensure-function(\(setf\ seq-elt\))
>>   cl-generic-define-method(\(setf\ seq-elt\) nil (store (sequence array) n)
>> nil #f(compiled-function (store sequence n)
>
> Hmm....
>
> When you see that, could you show us the value of:
>
>     (symbol-function '\(setf\ seq-elt\))

I installed the patch below which apparently fixes this problem


        Stefan


diff --git a/lisp/emacs-lisp/cl-generic.el b/lisp/emacs-lisp/cl-generic.el
index 31aa0cb4f9..544704be38 100644
--- a/lisp/emacs-lisp/cl-generic.el
+++ b/lisp/emacs-lisp/cl-generic.el
@@ -568,17 +568,17 @@ cl-generic-define-method
               (cons method mt)
             ;; Keep the ordering; important for methods with :extra qualifiers.
             (mapcar (lambda (x) (if (eq x (car me)) method x)) mt)))
-    (let ((sym (cl--generic-name generic))) ; Actual name (for aliases).
+    (let ((sym (cl--generic-name generic)) ; Actual name (for aliases).
+          ;; FIXME: Try to avoid re-constructing a new function if the old one
+          ;; is still valid (e.g. still empty method cache)?
+          (gfun (cl--generic-make-function generic)))
       (unless (symbol-function sym)
         (defalias sym 'dummy))   ;Record definition into load-history.
       (cl-pushnew `(cl-defmethod . ,(cl--generic-load-hist-format
                                      (cl--generic-name generic)
                                      qualifiers specializers))
                   current-load-list :test #'equal)
-      ;; FIXME: Try to avoid re-constructing a new function if the old one
-      ;; is still valid (e.g. still empty method cache)?
-      (let ((gfun (cl--generic-make-function generic))
-            ;; Prevent `defalias' from recording this as the definition site of
+      (let (;; Prevent `defalias' from recording this as the definition site of
             ;; the generic function.
             current-load-list
             ;; BEWARE!  Don't purify this function definition, since that leads