From: Noam Postavsky <npostavs@gmail.com>
Date: Tue, 28 May 2019 00:36:41 +0000 (-0400)
Subject: Warn about wrong number of args for subrs (Bug#35767)
X-Git-Tag: emacs-26.2.90~32
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=134edc1;p=emacs.git

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.
---

diff --git a/lisp/emacs-lisp/bytecomp.el b/lisp/emacs-lisp/bytecomp.el
index 9ea4179b68d..72e81a653c7 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 bc28c5a6a00..c399f65b402 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))))