org-colview: Fix `org-columns' with a prefix argument

* lisp/org-colview.el (org-columns): Fix `org-columns' with a prefix
  argument.
* testing/lisp/test-org-colview.el (test-org-colview/columns-scope):
  Update test.

Reported-by: Hendrik Tews <hendrik@askra.de>
<http://permalink.gmane.org/gmane.emacs.orgmode/113721>

lisp/org-colview.el

@@ -781,6 +781,7 @@ view for the whole buffer unconditionally.
 When COLUMNS-FMT-STRING is non-nil, use it as the column format."
   (interactive "P")
   (org-columns-remove-overlays)
+  (when global (goto-char (point-min)))
   (move-marker org-columns-begin-marker (point))
   (org-columns-goto-top-level)
   ;; Initialize `org-columns-current-fmt' and

testing/lisp/test-org-colview.el

@@ -104,9 +104,10 @@
        (lambda () (get-char-property (point) 'org-columns-value))))))
   (should
    (equal
-    '("H1" "H2" "H3" "H4")
-    (org-test-with-temp-text "Top\n* H1\n** <point>H2\n*** H3\n* H4"
-      (let ((org-columns-default-format "%ITEM")) (org-columns t))
+    '("1" "1")
+    (org-test-with-temp-text
+	"Top\n* H1\n** <point>H2\n:PROPERTIES:\n:A: 1\n:END:"
+      (let ((org-columns-default-format "%A{+}")) (org-columns t))
       (org-map-entries
        (lambda () (get-char-property (point) 'org-columns-value)))))))