Fix eieio vs cl-generic incompatibilities found in Rudel (bug#23947)

* lisp/emacs-lisp/cl-generic.el (cl-generic-apply): New function.
* lisp/emacs-lisp/eieio-compat.el (eieio--defmethod): Fix incorrect
mapping between cl-no-applicable-method and EIEIO's no-applicable-method.
* lisp/emacs-lisp/eieio-core.el (eieio--class-precedence-c3):
`class' is not a symbol but a class object.

3 files changed, 13 insertions, 3 deletions

diff --git a/lisp/emacs-lisp/cl-generic.el b/lisp/emacs-lisp/cl-generic.el
index e5bab8dba99..4f263c6bb8d 100644
--- a/lisp/emacs-lisp/cl-generic.el
+++ b/lisp/emacs-lisp/cl-generic.el
@@ -671,6 +671,15 @@ FUN is the function that should be called when METHOD calls
           (setq fun (cl-generic-call-method generic method fun)))
         fun)))))
 
+(defun cl-generic-apply (generic args)
+  "Like `apply' but takes a cl-generic object rather than a function."
+  ;; Handy in cl-no-applicable-method, for example.
+  ;; In Common Lisp, generic-function objects are funcallable.  Ideally
+  ;; we'd want the same in Elisp, but it would either require using a very
+  ;; different (and less efficient) representation of cl--generic objects,
+  ;; or non-trivial changes in the general infrastructure (compiler and such).
+  (apply (cl--generic-name generic) args))
+
 (defun cl--generic-arg-specializer (method dispatch-arg)
   (or (if (integerp dispatch-arg)
           (nth dispatch-arg
diff --git a/lisp/emacs-lisp/eieio-compat.el b/lisp/emacs-lisp/eieio-compat.el
index 6d4798b92f9..6aba8a3acbd 100644
--- a/lisp/emacs-lisp/eieio-compat.el
+++ b/lisp/emacs-lisp/eieio-compat.el
@@ -188,7 +188,8 @@ Summary:
             (`no-applicable-method
              (setq method 'cl-no-applicable-method)
              (setq specializers `(generic ,@specializers))
-             (lambda (generic arg &rest args) (apply code arg generic args)))
+             (lambda (generic arg &rest args)
+               (apply code arg (cl--generic-name generic) (cons arg args))))
             (_ code))))
     (cl-generic-define-method
      method (unless (memq kind '(nil :primary)) (list kind))
diff --git a/lisp/emacs-lisp/eieio-core.el b/lisp/emacs-lisp/eieio-core.el
index 631e4a437f2..223c2a69a62 100644
--- a/lisp/emacs-lisp/eieio-core.el
+++ b/lisp/emacs-lisp/eieio-core.el
@@ -976,7 +976,7 @@ If a consistent order does not exist, signal an error."
 
 (defun eieio--class-precedence-c3 (class)
   "Return all parents of CLASS in c3 order."
-  (let ((parents (eieio--class-parents (cl--find-class class))))
+  (let ((parents (eieio--class-parents class)))
     (eieio--c3-merge-lists
      (list class)
      (append
@@ -1101,7 +1101,7 @@ method invocation orders of the involved classes."
   (list eieio--generic-subclass-generalizer))
 
 
-;;;### (autoloads nil "eieio-compat" "eieio-compat.el" "6aca3c1b5f751a01331761da45fc4f5c")
+;;;### (autoloads nil "eieio-compat" "eieio-compat.el" "dba4205b1a0d7133f1311d975b4d0ebe")
 ;;; Generated autoloads from eieio-compat.el
 
 (autoload 'eieio--defalias "eieio-compat" "\