commit 686bd788243ef38951c3c529d4c67c3ad766f417
Author: Michael Brand <michael.ch.brand@gmail.com>
Date:   Sat Nov 16 16:13:57 2013 +0100

    Hyperlink: Use url-encode-url for browse-url
    
    * lisp/org.el (org-open-at-point): When available (Emacs 24.3) use
    `url-encode-url' instead of `org-link-escape-browser'.
    
    * testing/lisp/test-org.el
    (test-org/org-link-escape-url-with-escaped-char): Substitute repeated
    literal string with constant.
    (test-org/org-link-escape-chars-browser): Extend test coverage with
    `url-encode-url' and with "query="-space as plus sign or space.

diff --git a/lisp/org.el b/lisp/org.el
index a3c1958..aa91ffc 100644
--- a/lisp/org.el
+++ b/lisp/org.el
@@ -10468,11 +10468,20 @@ application the system uses for this file type."
 	      (apply cmd (nreverse args1))))
 
 	   ((member type '("http" "https" "ftp" "news"))
-	    (browse-url (concat type ":" (org-link-escape-browser path))))
+	    ;; see `ert-deftest'
+	    ;; `test-org/org-link-escape-chars-browser'
+	    (browse-url
+	     (if (fboundp 'url-encode-url)
+		 (url-encode-url (concat type ":" path))
+	       (org-link-escape-browser (concat type ":" path)))))
 
 	   ((string= type "doi")
-	    (browse-url (concat org-doi-server-url
-				(org-link-escape-browser path))))
+	    ;; see `ert-deftest'
+	    ;; `test-org/org-link-escape-chars-browser'
+	    (browse-url
+	     (if (fboundp 'url-encode-url)
+		 (url-encode-url (concat org-doi-server-url path))
+	       (org-link-escape-browser (concat org-doi-server-url path)))))
 
 	   ((member type '("message"))
 	    (browse-url (concat type ":" path)))
diff --git a/testing/lisp/test-org.el b/testing/lisp/test-org.el
index f4672eb..084e95d 100644
--- a/testing/lisp/test-org.el
+++ b/testing/lisp/test-org.el
@@ -552,21 +552,53 @@
 (ert-deftest test-org/org-link-escape-url-with-escaped-char ()
   "Escape and unescape a URL that includes an escaped char.
 http://article.gmane.org/gmane.emacs.orgmode/21459/"
-  (should
-   (string=
-    "http://some.host.com/form?&id=blah%2Bblah25"
-    (org-link-unescape
-     (org-link-escape "http://some.host.com/form?&id=blah%2Bblah25")))))
+  (let ((a "http://some.host.com/form?&id=blah%2Bblah25"))
+    (should (string= a (org-link-unescape (org-link-escape a))))))
 
 (ert-deftest test-org/org-link-escape-chars-browser ()
-  "Escape a URL to pass to `browse-url'."
-  (should
-   (string=
-    (concat "http://lists.gnu.org/archive/cgi-bin/namazu.cgi?query="
-	    "%22Release%208.2%22&idxname=emacs-orgmode")
-    (org-link-escape-browser
-     (concat "http://lists.gnu.org/archive/cgi-bin/namazu.cgi?query="
-	     "\"Release 8.2\"&idxname=emacs-orgmode")))))
+  "Escape a URL before passing it to `browse-url'.
+
+This test is to ensure that `org-open-at-point' on the Org links
+
+    [[http://lists.gnu.org/archive/cgi-bin/namazu.cgi?idxname=emacs-orgmode&query=%252Bsubject:\"Release+8.2\"]]
+    [[http://lists.gnu.org/archive/cgi-bin/namazu.cgi?idxname=emacs-orgmode&query=%252Bsubject:\"Release 8.2\"]]
+
+will open a browser with +subject:\"Release 8.2\" in the query
+field."
+
+  ;; Each string argument passed to `url-encode-url' or
+  ;; `org-link-escape-browser' in the tests below (or when
+  ;; `org-open-at-point' is used in an Org buffer) looks like after
+  ;; the Org link from the docstring has been unescaped by
+  ;; `org-link-unescape' in `org-open-at-point'
+  (let ((query (concat "http://lists.gnu.org/archive/cgi-bin/namazu.cgi?"
+		       "idxname=emacs-orgmode&query="))
+	(plus  "%2Bsubject:\"Release+8.2\"")   ; "query="-space as plus sign
+	(space "%2Bsubject:\"Release 8.2\""))  ; "query="-space as space
+
+    ;; This is the behavior of `org-open-at-point' when used together
+    ;; with an Emacs 24.3 or later where `url-encode-url' is available
+    (when (fboundp 'url-encode-url)
+      ;; "query="-space as plus sign
+      (should (string= (concat query "%2Bsubject:%22Release+8.2%22")
+		       (url-encode-url (concat query plus))))
+      ;; "query="-space as space
+      (should (string= (concat query "%2Bsubject:%22Release%208.2%22")
+		       (url-encode-url (concat query space)))))
+
+    ;; The %252B below returned from `org-link-escape-browser' is not
+    ;; desired and not working with some browser/OS but tested here to
+    ;; document what happens when the fallback to
+    ;; `org-link-escape-browser' in `org-open-at-point' is in use,
+    ;; which is the legacy behavior of `org-open-at-point' when used
+    ;; together with an Emacs before version 24.3
+    ;;
+    ;; "query="-space as plus sign
+    (should (string= (concat query "%252Bsubject:%22Release+8.2%22")
+		     (org-link-escape-browser (concat query plus))))
+    ;; "query="-space as space
+    (should (string= (concat query "%252Bsubject:%22Release%208.2%22")
+		     (org-link-escape-browser (concat query space))))))