Add test for previous commit

* test/automated/replace-tests.el: New file.
(query-replace--split-string-tests): Add test for previous commit.

test/automated/replace-tests.el

+;;; replace-tests.el --- tests for replace.el.
+
+;; Copyright (C) 2015 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+
+(ert-deftest query-replace--split-string-tests ()
+  (let ((sep (propertize "\0" 'separator t)))
+    (dolist (before '("" "b"))
+      (dolist (after '("" "a"))
+        (should (equal
+                 (query-replace--split-string (concat before sep after))
+                 (cons before after)))
+        (should (equal
+                 (query-replace--split-string (concat before "\0" after))
+                 (concat before "\0" after)))))))
+
+;;; replace-tests.el ends here