Fix bug #14306 with whitespace mode together with linum-mode.

 src/xdisp.c (set_iterator_to_next): Set the
 ignore_overlay_strings_at_pos_p flag only if we are _really_
 iterating over an overlay string, as indicated by the
 current.overlay_string_index member.

lisp/mail/rmail.el

@@ -4752,7 +4752,7 @@ If prefix argument REVERSE is non-nil, sorts in reverse order.
 
 ;;;### (autoloads (rmail-summary-by-senders rmail-summary-by-topic
 ;;;;;;  rmail-summary-by-regexp rmail-summary-by-recipients rmail-summary-by-labels
-;;;;;;  rmail-summary) "rmailsum" "rmailsum.el" "119ce8b431f01e7f54bb6fa99603b3d9")
+;;;;;;  rmail-summary) "rmailsum" "rmailsum.el" "61e7ad0931be1e07034dd57825ff326a")
 ;;; Generated autoloads from rmailsum.el
 
 (autoload 'rmail-summary "rmailsum" "\

src/ChangeLog

+2013-05-05  Eli Zaretskii  <eliz@gnu.org>
+
+	* xdisp.c (set_iterator_to_next): Set the
+	ignore_overlay_strings_at_pos_p flag only if we are _really_
+	iterating over an overlay string, as indicated by the
+	current.overlay_string_index member.  (Bug#14306)
+
 2013-05-05  Jan Djärv  <jan.h.d@swipnet.se>
 
 	* nsmenu.m (ns_update_menubar): Move initialization of submenuTitle

src/xdisp.c

@@ -7153,6 +7153,7 @@ set_iterator_to_next (struct it *it, int reseat_p)
 	  else if (it->dpvec_char_len > 0)
 	    {
 	      if (it->method == GET_FROM_STRING
+		  && it->current.overlay_string_index >= 0
 		  && it->n_overlay_strings > 0)
 		it->ignore_overlay_strings_at_pos_p = 1;
 	      it->len = it->dpvec_char_len;