org-agenda: Fix agenda standard name when going unsticky

* lisp/org-agenda.el (org-agenda-list): Reset `org-agenda-buffer-name'
  to the original name.
* testing/lisp/test-org-agenda.el: Pertaining unit test.  + 2 basic
  agenda tests.
* testing/examples/agenda-file.org: File to produce content for an
  agenda to test.

lisp/org-agenda.el

@@ -4207,7 +4207,7 @@ items if they have an hour specification like [h]h:mm."
 			(org-keys
 			 (format "*Org Agenda(%s)*" org-keys))
 			(t "*Org Agenda(a)*")))
-	      org-agenda-buffer-name))
+	      "*Org Agenda*"))
     (org-agenda-prepare "Day/Week")
     (setq start-day (or start-day org-agenda-start-day))
     (if (stringp start-day)

testing/examples/agenda-file.org

@@ -0,0 +1,3 @@
+* Test Agenda
+
+<2017-03-10 Fri>

testing/lisp/test-org-agenda.el

@@ -0,0 +1,117 @@
+;;; test-org-agenda.el --- Tests for org-agenda.el -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2017 Marco Wahl
+
+;; Author: Marco Wahl <marcowahlsoft@gmail.com>
+
+;; 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/>.
+
+;;; Commentary:
+
+;; Unit tests for Org Agenda.
+
+;;; Code:
+
+(require 'org-test)
+(require 'org-agenda)
+
+
+;; Auxilliaries for set-up and tear-down and more.
+
+(defun -sha1-as-defun-name-accc70505c6664ed226e3afa45ca0ecc95a35e83 ()
+  "Name a function with the sha1 of the function text.
+Use this function if you are too lazy to invent a function name.
+The function text starts at the argument list and ends at the
+last paren (exclusive)."
+  (interactive)
+  (save-excursion
+    (let* ((start (progn
+                    (beginning-of-defun)
+                    (search-forward-regexp "\(" nil nil 2)
+                    (backward-char)
+                    (point)))
+           (end (progn
+                  (end-of-defun)
+                  (backward-char)
+                  (point)))
+           (sha1 (sha1 (current-buffer) start end)))
+      ;; relying on (point) is within the defun
+      (progn
+        (beginning-of-defun)
+        (search-forward-regexp " ")
+        (skip-chars-forward " \t")
+        (just-one-space))
+      (unless (= ?\( (char-after))
+        (delete-region (point) (progn (forward-word) (point)))
+        (just-one-space))
+      (insert sha1 " "))))
+
+(defun -kill-all-agendas ()
+  "Kill all agenda buffers."
+  (mapc #'kill-buffer
+        (cl-remove-if-not
+         (lambda (x)
+           (set-buffer x)
+           (eq major-mode 'org-agenda-mode))
+         (buffer-list))))
+
+
+;; Test the Agenda
+
+(ert-deftest org-e9d91f5add1245445ba773dd74ac534273113ca5 ()
+  "Empty agenda."
+  (let ((org-agenda-span 'day)
+        org-agenda-files)
+    (org-agenda-list)
+    (set-buffer org-agenda-buffer-name)
+    (should (= 2 (count-lines (point-min) (point-max))))))
+
+(ert-deftest org-a0116aeccdedc04580e42933a16c2893d76ee6bc ()
+  "One informative line in the agenda."
+  (let ((org-agenda-span 'day)
+	(org-agenda-files `(,(expand-file-name "examples/agenda-file.org" org-test-dir))))
+    (org-agenda-list nil  "<2017-03-10 Fri>")
+    (set-buffer org-agenda-buffer-name)
+    (should (= 3 (count-lines (point-min) (point-max))))))
+
+(ert-deftest org-165802102bb2d2accf16ff0ae362ef51945ae69f ()
+  "Agenda buffer name after having created one sticky agenda buffer."
+  (-kill-all-agendas)
+  ;; (setq org-agenda-buffer-name "*Org Agenda*")
+  (let ((org-agenda-span 'day)
+	(org-agenda-buffer-name "*Org Agenda*")
+	(default-org-agenda-buffer-name org-agenda-buffer-name)
+	(buf (get-buffer org-agenda-buffer-name))
+        org-agenda-files)
+    (when buf (kill-buffer buf))
+    (org-test-with-temp-text "<2017-03-17 Fri>"
+      (org-follow-timestamp-link) 	; creates a sticky agenda.
+      )
+    (-kill-all-agendas)
+    (org-agenda-list)
+    (let ((agenda-buffers
+	   (cl-remove-if-not
+	    (lambda (x)
+	      (set-buffer x)
+	      (eq major-mode 'org-agenda-mode))
+	    (buffer-list))))
+      (should (= 1 (length agenda-buffers)))
+      (should (string= default-org-agenda-buffer-name
+                       (buffer-name (car agenda-buffers))))))
+  (-kill-all-agendas))
+
+
+(provide 'test-org-agenda)
+
+;;; test-org-agenda.el ends here