* lisp/isearch.el (isearch-pre-command-hook): Use this-single-command-keys

instead of this-command-keys.  Add universal-argument-more and
universal-argument-minus to the list of prefix commands.

Fixes: debbugs:15568

lisp/ChangeLog

@@ -1,3 +1,9 @@
+2013-10-09  Juri Linkov  <juri@jurta.org>
+
+	* isearch.el (isearch-pre-command-hook): Use this-single-command-keys
+	instead of this-command-keys.  Add universal-argument-more and
+	universal-argument-minus to the list of prefix commands.  (Bug#15568)
+
 2013-10-09  Glenn Morris  <rgm@gnu.org>
 
 	* vc/vc-svn.el (vc-svn-create-repo):

lisp/isearch.el

@@ -2230,11 +2230,10 @@ a prefix argument command (when `isearch-allow-prefix' is non-nil),
 or it is a scrolling command (when `isearch-allow-scroll' is non-nil).
 Otherwise, exit Isearch (when `search-exit-option' is non-nil)
 before the command is executed globally with terminated Isearch."
-  (let* ((key (this-command-keys))
+  (let* ((key (this-single-command-keys))
 	 (main-event (aref key 0)))
     (cond
      ;; Don't exit Isearch for isearch key bindings.
-     ;; FIXME: remove prefix arg to lookup key without prefix.
      ((commandp (lookup-key isearch-mode-map key nil)))
      ;; Optionally edit the search string instead of exiting.
      ((eq search-exit-option 'edit)
@@ -2242,8 +2241,9 @@ before the command is executed globally with terminated Isearch."
      ;; Handle a scrolling function or prefix argument.
      ((or (and isearch-allow-prefix
 	       (memq this-command '(universal-argument
-				    negative-argument
-				    digit-argument)))
+				    universal-argument-more
+				    universal-argument-minus
+				    digit-argument negative-argument)))
 	  (and isearch-allow-scroll
 	       (or (eq (get this-command 'isearch-scroll) t)
 		   (eq (get this-command 'scroll-command) t))))