`org-open-line' ignores tables at the very beginning of the document

* lisp/org.el (org-open-line): Ignore tables at the very beginning of
  the document.
* testing/lisp/test-org.el (test-org/open-line): New test.

etc/ORG-NEWS

@@ -518,7 +518,10 @@ to force opening it in either Emacs or with system application.
 *** New defalias ~org-babel-execute:j~
 Allows J source blocks be indicated by letter j.  Previously the
 indication letter was solely J.
-
+*** ~org-open-line~ ignores tables at the very beginning of the buffer
+When ~org-special-ctrl-o~ is non-nil, it is impractical to create
+a blank line above a table at the beginning of the document. Now, as
+a special case, ~org-open-line~ behaves normally in this situation.
 * Version 8.3
 
 ** Incompatible changes

lisp/org.el

@@ -21291,15 +21291,13 @@ With argument, join this line to following line."
 
 (defun org-open-line (n)
   "Insert a new row in tables, call `open-line' elsewhere.
-If `org-special-ctrl-o' is nil, just call `open-line' everywhere."
+If `org-special-ctrl-o' is nil, just call `open-line' everywhere.
+As a special case, when a document starts with a table, allow to
+call `open-line' on the very first character."
   (interactive "*p")
-  (cond
-   ((not org-special-ctrl-o)
-    (open-line n))
-   ((org-at-table-p)
-    (org-table-insert-row))
-   (t
-    (open-line n))))
+  (if (and org-special-ctrl-o (/= (point) 1) (org-at-table-p))
+      (org-table-insert-row)
+    (open-line n)))
 
 (defun org-return (&optional indent)
   "Goto next table row or insert a newline.

testing/lisp/test-org.el

@@ -2487,6 +2487,35 @@ http://article.gmane.org/gmane.emacs.orgmode/21459/"
        (org-end-of-line)
        (eobp)))))
 
+(ert-deftest test-org/open-line ()
+  "Test `org-open-line' specifications."
+  ;; Call `open-line' outside of tables.
+  (should
+   (equal "\nText"
+	  (org-test-with-temp-text "Text"
+	    (org-open-line 1)
+	    (buffer-string))))
+  ;; At a table, create a row above.
+  (should
+   (equal "\n|   |\n| a |"
+	  (org-test-with-temp-text "\n<point>| a |"
+	    (org-open-line 1)
+	    (buffer-string))))
+  ;; At the very first character of the buffer, also call `open-line'.
+  (should
+   (equal "\n| a |"
+	  (org-test-with-temp-text "| a |"
+	    (org-open-line 1)
+	    (buffer-string))))
+  ;; Narrowing does not count.
+  (should
+   (equal "Text\n|   |\n| a |"
+	  (org-test-with-temp-text "Text\n<point>| a |"
+	    (narrow-to-region (point) (point-max))
+	    (org-open-line 1)
+	    (widen)
+	    (buffer-string)))))
+
 (ert-deftest test-org/forward-sentence ()
   "Test `org-forward-sentence' specifications."
   ;; At the end of a table cell, move to the end of the next one.