Fix bug in how ERT invokes its debugger.

The debugger needs to receive a list of the error symbol and data;
cf. the documentation of the `debugger' variable.  This bug manifested
itself in ERT forms such as (should (integerp (ert-fail "Boo"))),
which resulted in an incorrect condition object.  Note that forms such
as (should (ert-fail "Boo")) weren't affected because they wouldn't
use the `ert--should-signal-hook'.

* test/emacs-lisp/ert.el (ert--should-signal-hook): Call debugger with
the right arguments.

* test/lisp/emacs-lisp/ert-tests.el (ert-test-fail-inside-should): Add
unit test.

1 files changed, 1 insertions, 1 deletions

diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index 5f29c2665a3..25237feae2a 100644
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -274,7 +274,7 @@ DATA is displayed to the user and should state the reason for skipping."
 It should only be stopped when ran from inside ert--run-test-internal."
   (when (and (not (symbolp debugger))   ; only run on anonymous debugger
              (memq error-symbol '(ert-test-failed ert-test-skipped)))
-    (funcall debugger 'error data)))
+    (funcall debugger 'error (list error-symbol data))))
 
 (defun ert--special-operator-p (thing)
   "Return non-nil if THING is a symbol naming a special operator."