* lisp/subr.el (derived-mode-p): Disable warnings for old convention

1 files changed, 5 insertions, 1 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index 7f2dcdc4d90..7b52f4f68f9 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -2804,7 +2804,11 @@ MODES should be a list of symbols or a single mode symbol instead of a list.
 We also still support the deprecated calling convention:
 \(derived-mode-p &rest MODES)."
  (declare (side-effect-free t)
-          (advertised-calling-convention (modes) "30.1"))
+          ;; FIXME: It's cumbersome for external packages to write code which
+          ;; accommodates both the old and the new calling conventions *and*
+          ;; doesn't cause spurious warnings.  So let's be more lenient
+          ;; for now and maybe remove `deprecated-args' for Emacs-31.
+          (advertised-calling-convention (modes &rest deprecated-args) "30.1"))
  (provided-mode-derived-p major-mode (if old-modes (cons modes old-modes)
                                        modes)))