Use lexical-binding in tests and fix crash exposed0.19

argdesc in byte-code function objects may be an integer rather than a
list, so handle that case gracefully.

2 files changed, 10 insertions, 1 deletions

diff --git a/helpful.el b/helpful.el
index 3ec6ed9..c4cdd28 100644
--- a/helpful.el
+++ b/helpful.el
@@ -2470,7 +2470,14 @@ For example, \"(some-func FOO &optional BAR)\"."
              ((symbolp sym)
               (help-function-arglist sym))
              ((byte-code-function-p sym)
-              (aref sym 0))
+              ;; argdesc can be a list of arguments or an integer
+              ;; encoding the min/max number of arguments. See
+              ;; Byte-Code Function Objects in the elisp manual.
+              (let ((argdesc (aref sym 0)))
+                (if (consp argdesc)
+                    argdesc
+                  ;; TODO: properly handle argdesc values.
+                  nil)))
              (t
               ;; Interpreted function (lambda ...)
               (cadr sym))))
diff --git a/test/helpful-unit-test.el b/test/helpful-unit-test.el
index 4e87efe..a07aa8e 100644
--- a/test/helpful-unit-test.el
+++ b/test/helpful-unit-test.el
@@ -1,3 +1,5 @@
+;;; helpful-unit-test.el -*- lexical-binding: t; -*-
+
 (require 'ert)
 (require 'edebug)
 (require 'helpful)