* replace.el (occur-engine): Avoid infloop.

Fixes: debbugs:7593

lisp/ChangeLog

+2013-12-18  Chong Yidong  <cyd@gnu.org>
+
+	* replace.el (occur-engine): Avoid infloop (Bug#7593).
+
 2013-12-18  Kazuhiro Ito  <kzhr@d1.dion.ne.jp>  (tiny change)
 
 	* progmodes/make-mode.el (makefile-fill-paragraph): Fix infloop

lisp/replace.el

@@ -1457,7 +1457,9 @@ See also `multi-occur'."
 			    ;; so as to override faces copied from the buffer.
 			    `(face ,match-face)))
 			 curstring)
-			(setq start (match-end 0))))
+			;; Avoid infloop (Bug#7593).
+			(let ((end (match-end 0)))
+			  (setq start (if (= start end) (1+ start) end)))))
 		    ;; Generate the string to insert for this match
 		    (let* ((match-prefix
 			    ;; Using 7 digits aligns tabs properly.