Check that variable lists are actually lists

'let' and 'let*' document that their first argument has to be a list,
but don't check for that; instead, they allow (and silently ignore)
other types.  Introduce an explicit type check.

* src/eval.c (Flet, FletX): Check that the variable list is indeed a
list.
* test/src/eval-tests.el: Add unit tests.

1 files changed, 10 insertions, 0 deletions

diff --git a/test/src/eval-tests.el b/test/src/eval-tests.el
index a1fe8ccd7d9..95655eac826 100644
--- a/test/src/eval-tests.el
+++ b/test/src/eval-tests.el
@@ -47,4 +47,14 @@ Bug#24912 and Bug#24913."
     (let ((byte-compile-debug t))
       (should-error (eval `(byte-compile (lambda ,args)) t)))))
 
+
+(dolist (form '(let let*))
+  (dolist (arg '(1 "a" [a]))
+    (eval
+     `(ert-deftest ,(intern (format "eval-tests--%s--%s" form (type-of arg))) ()
+        ,(format "Check that the first argument of `%s' cannot be a %s"
+                 form (type-of arg))
+        (should-error (,form ,arg) :type 'wrong-type-argument))
+     t)))
+
 ;;; eval-tests.el ends here