[Emacs-diffs] emacs-26 134edc1 2/2: Warn about wrong number of args for subrs (Bug#35767)

[Noam Postavsky]

branch: emacs-26
commit 134edc10367a8434167656e631865c85b5f10c42
Author: Noam Postavsky <address@hidden>
Commit: Noam Postavsky <address@hidden>

    Warn about wrong number of args for subrs (Bug#35767)
    
    * lisp/emacs-lisp/bytecomp.el (byte-compile-callargs-warn): Don't
    assume byte-compile-fdefinition will return non-nil.
    * test/lisp/emacs-lisp/bytecomp-tests.el (bytecomp-warn-wrong-args)
    (bytecomp-warn-wrong-args-subr): New tests.
---
 lisp/emacs-lisp/bytecomp.el            |  2 +-
 test/lisp/emacs-lisp/bytecomp-tests.el | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 9ea4179..72e81a6 100644
--- a/lisp/emacs-lisp/bytecomp.el
+++ b/lisp/emacs-lisp/bytecomp.el
@@ -1379,7 +1379,7 @@ when printing the error message."
 (defun byte-compile-callargs-warn (form)
   (let* ((def (or (byte-compile-fdefinition (car form) nil)
                  (byte-compile-fdefinition (car form) t)))
-        (sig (byte-compile--function-signature def))
+         (sig (byte-compile--function-signature (or def (car form))))
         (ncall (length (cdr form))))
     ;; Check many or unevalled from subr-arity.
     (if (and (cdr-safe sig)
diff --git a/test/lisp/emacs-lisp/bytecomp-tests.el 
b/test/lisp/emacs-lisp/bytecomp-tests.el
index bc28c5a..c399f65 100644
--- a/test/lisp/emacs-lisp/bytecomp-tests.el
+++ b/test/lisp/emacs-lisp/bytecomp-tests.el
@@ -438,6 +438,20 @@ Subtests signal errors if something goes wrong."
     ;; Should not warn that mt--test2 is not known to be defined.
     (should-not (re-search-forward "my--test2" nil t))))
 
+(ert-deftest bytecomp-warn-wrong-args ()
+  (with-current-buffer (get-buffer-create "*Compile-Log*")
+    (let ((inhibit-read-only t)) (erase-buffer))
+    (byte-compile '(remq 1 2 3))
+    (ert-info ((buffer-string) :prefix "buffer: ")
+      (should (re-search-forward "remq.*3.*2")))))
+
+(ert-deftest bytecomp-warn-wrong-args-subr ()
+  (with-current-buffer (get-buffer-create "*Compile-Log*")
+    (let ((inhibit-read-only t)) (erase-buffer))
+    (byte-compile '(safe-length 1 2 3))
+    (ert-info ((buffer-string) :prefix "buffer: ")
+      (should (re-search-forward "safe-length.*3.*1")))))
+
 (ert-deftest test-eager-load-macro-expansion ()
   (test-byte-comp-compile-and-load nil
     '(progn (defmacro abc (arg) 1) (defun def () (abc 2))))