org-datetree: Fix DATE_TREE search

* lisp/org-datetree.el (org-datetree-find-date-create): Ignore case and
  discard false positives (e.g., a fake property in an example block).

* testing/lisp/test-org-datetree.el: New file.

lisp/org-datetree.el

@@ -54,23 +54,22 @@ Added time stamp is active unless value is `inactive'."
 If KEEP-RESTRICTION is non-nil, do not widen the buffer.
 When it is nil, the buffer will be widened to make sure an existing date
 tree can be found."
-  (let ((year (nth 2 date))
-	(month (car date))
-	(day (nth 1 date)))
-    (org-set-local 'org-datetree-base-level 1)
-    (or keep-restriction (widen))
-    (goto-char (point-min))
-    (save-restriction
-      (when (re-search-forward "^[ \t]*:DATE_TREE:[ \t]+\\S-" nil t)
-	(org-back-to-heading t)
+  (org-set-local 'org-datetree-base-level 1)
+  (or keep-restriction (widen))
+  (save-restriction
+    (let ((prop (org-find-property "DATE_TREE")))
+      (when prop
+	(goto-char prop)
 	(org-set-local 'org-datetree-base-level
-		       (org-get-valid-level (funcall outline-level) 1))
-	(org-narrow-to-subtree))
-      (goto-char (point-min))
+		       (org-get-valid-level (org-current-level) 1))
+	(org-narrow-to-subtree)))
+    (goto-char (point-min))
+    (let ((year (nth 2 date))
+	  (month (car date))
+	  (day (nth 1 date)))
       (org-datetree-find-year-create year)
       (org-datetree-find-month-create year month)
-      (org-datetree-find-day-create year month day)
-      (goto-char (prog1 (point) (widen))))))
+      (org-datetree-find-day-create year month day))))
 
 (defun org-datetree-find-year-create (year)
   "Find the YEAR datetree or create it."

testing/lisp/test-org-datetree.el

@@ -0,0 +1,108 @@
+;;; test-org-datetree.el --- Tests for Org Datetree  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2015  Nicolas Goaziou
+
+;; Author: Nicolas Goaziou <mail@nicolasgoaziou.fr>
+
+;; This file is not 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:
+
+(ert-deftest test-org-datetree/find-date-create ()
+  "Test `org-datetree-find-date-create' specifications."
+  ;; When date is missing, create it.
+  (should
+   (string-match
+    "\\`\\* 2012\n\\*\\* 2012-03 .*\n\\*\\*\\* 2012-03-29 .*\\'"
+    (org-test-with-temp-text ""
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  ;; Do not create new year node when one exists.
+  (should
+   (string-match
+    "\\`\\* 2012\n\\*\\* 2012-03 .*\n\\*\\*\\* 2012-03-29 .*\\'"
+    (org-test-with-temp-text "* 2012\n"
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  ;; Do not create new month node when one exists.
+  (should
+   (string-match
+    "\\`\\* 2012\n\\*\\* 2012-03 .*\n\\*\\*\\* 2012-03-29 .*\\'"
+    (org-test-with-temp-text "* 2012\n** 2012-03 month"
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  ;; Do not create new day node when one exists.
+  (should
+   (string-match
+    "\\`\\* 2012\n\\*\\* 2012-03 .*\n\\*\\*\\* 2012-03-29 .*\\'"
+    (org-test-with-temp-text "* 2012\n** 2012-03 month\n*** 2012-03-29 day"
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  ;; When `org-datetree-add-timestamp' is non-nil, insert a timestamp
+  ;; in entry.  When set to `inactive', insert an inactive one.
+  (should
+   (string-match
+    "\\`\\* 2012\n\\*\\* 2012-03 .*\n\\*\\*\\* \\(2012-03-29\\) .*\n[ \t]*<\\1.*?>\\'"
+    (org-test-with-temp-text "* 2012\n"
+      (let ((org-datetree-add-timestamp t))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  (should
+   (string-match
+    "\\`\\* 2012\n\\*\\* 2012-03 .*\n\\*\\*\\* \\(2012-03-29\\) .*\n[ \t]*\\[\\1.*?\\]\\'"
+    (org-test-with-temp-text "* 2012\n"
+      (let ((org-datetree-add-timestamp 'inactive))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  ;; Insert at top level, unless some node has DATE_TREE property.  In
+  ;; this case, date tree becomes one of its sub-trees.
+  (should
+   (string-match
+    "\\* 2012"
+    (org-test-with-temp-text "* Top"
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  (should
+   (string-match
+    "\\*\\* H1.1\n:PROPERTIES:\n:DATE_TREE: t\n:END:\n\\*\\*\\* 2012"
+    (org-test-with-temp-text
+	"* H1\n** H1.1\n:PROPERTIES:\n:DATE_TREE: t\n:END:\n* H2"
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (org-trim (buffer-string)))))
+  ;; Always leave point at beginning of day entry.
+  (should
+   (string-match
+    "\\*\\*\\* 2012-03-29"
+    (org-test-with-temp-text "* 2012\n** 2012-03 month\n*** 2012-03-29 day"
+      (let ((org-datetree-add-timestamp nil))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (buffer-substring (point) (line-end-position)))))
+  (should
+   (string-match
+    "\\*\\*\\* 2012-03-29"
+    (org-test-with-temp-text "* 2012\n** 2012-03 month\n*** 2012-03-29 day"
+      (let ((org-datetree-add-timestamp t))
+	(org-datetree-find-date-create '(3 29 2012)))
+      (buffer-substring (point) (line-end-position))))))
+
+(provide 'test-org-datetree)
+;;; test-org-datetree.el ends here