(byte-compile-inline-expand):

If the function definition is not a lambda, return original FORM
with no error.

1 files changed, 4 insertions, 2 deletions

diff --git a/lisp/emacs-lisp/byte-opt.el b/lisp/emacs-lisp/byte-opt.el
index 4cf9548e8fb..a279c018e70 100644
--- a/lisp/emacs-lisp/byte-opt.el
+++ b/lisp/emacs-lisp/byte-opt.el
@@ -278,8 +278,10 @@
               (cons (list 'lambda (aref fn 0)
                           (list 'byte-code string (aref fn 2) (aref fn 3)))
                     (cdr form)))
-          (if (not (eq (car fn) 'lambda)) (error "%s is not a lambda" name))
-          (cons fn (cdr form)))))))
+          (if (eq (car-safe fn) 'lambda)
+              (cons fn (cdr form))
+            ;; Give up on inlining.
+            form))))))
 
 ;;; ((lambda ...) ...)
 ;;;