Add tests for copying properties by 'format'

* test/src/editfns-tests.el (format-properties): New test.

test/src/editfns-tests.el

@@ -0,0 +1,57 @@
+;;; editfns-tests.el -- tests for editfns.c
+
+;; Copyright (C) 2016 Free Software Foundation, Inc.
+
+;; This file is part of GNU Emacs.
+
+;; This program 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.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Code:
+
+(require 'ert)
+
+(ert-deftest format-properties ()
+  ;; Bug #23730
+  (should (ert-equal-including-properties
+           (format (propertize "%d" 'face '(:background "red")) 1)
+           #("1" 0 1 (face (:background "red")))))
+  (should (ert-equal-including-properties
+           (format (propertize "%2d" 'face '(:background "red")) 1)
+           #(" 1" 0 2 (face (:background "red")))))
+  (should (ert-equal-including-properties
+           (format (propertize "%02d" 'face '(:background "red")) 1)
+           #("01" 0 2 (face (:background "red")))))
+  (should (ert-equal-including-properties
+           (format (concat (propertize "%2d" 'x 'X)
+                           (propertize "a" 'a 'A)
+                           (propertize "b" 'b 'B))
+                   1)
+           #(" 1ab" 0 2 (x X) 2 3 (a A) 3 4 (b B))))
+
+  ;; Bug #5306
+  (should (ert-equal-including-properties
+           (format "%.10s"
+                   (concat "1234567890aaaa"
+                           (propertize "12345678901234567890" 'xxx 25)))
+           "1234567890"))
+  (should (ert-equal-including-properties
+           (format "%.10s"
+                   (concat "123456789"
+                           (propertize "12345678901234567890" 'xxx 25)))
+           #("1234567891" 9 10 (xxx 25))))
+
+  ;; Bug #23859
+  (should (ert-equal-including-properties
+           (format "%4s" (propertize "hi" 'face 'bold))
+           #("  hi" 0 4 (face bold)))))