Don't require bytecomp for running ert tests

"Fix ert-tests when running compiled" 2016-12-06 accidentally
introduced a dependency on `bytecomp' into `ert'.  As mentioned in
"Avoid ert test failures" 2017-04-18, the accidental dependency of ert
on bytecomp was masked by loading other libraries until recently.

* lisp/emacs-lisp/ert.el (ert--expand-should-1): Only use
`byte-compile-macro-environment' if it's bound.
* test/src/eval-tests.el: Add defvar for dynamic variable
`byte-compile-debug'.

2 files changed, 4 insertions, 2 deletions

diff --git a/lisp/emacs-lisp/ert.el b/lisp/emacs-lisp/ert.el
index f4c61e625d8..280b76acfe4 100644
--- a/lisp/emacs-lisp/ert.el
+++ b/lisp/emacs-lisp/ert.el
@@ -275,9 +275,9 @@ DATA is displayed to the user and should state the reason for skipping."
 
 (defun ert--expand-should-1 (whole form inner-expander)
   "Helper function for the `should' macro and its variants."
-  (require 'bytecomp)                   ; FIXME?
   (let ((form
-         (macroexpand form (append byte-compile-macro-environment
+         (macroexpand form (append (bound-and-true-p
+                                    byte-compile-macro-environment)
                                    (cond
                                     ((boundp 'macroexpand-all-environment)
                                      macroexpand-all-environment)
diff --git a/test/src/eval-tests.el b/test/src/eval-tests.el
index 95655eac826..03f408716b1 100644
--- a/test/src/eval-tests.el
+++ b/test/src/eval-tests.el
@@ -32,6 +32,8 @@
   ;; This should not crash.
   (should-error (funcall '(closure)) :type 'invalid-function))
 
+(defvar byte-compile-debug)
+
 (ert-deftest eval-tests--bugs-24912-and-24913 ()
   "Checks that Emacs doesn’t accept weird argument lists.
 Bug#24912 and Bug#24913."