Fix bug #17585 with incorrect vertical motion when linum-mode is on.

 src/xdisp.c (move_it_in_display_line_to): Don't record wrap position
 if we are iterating over an object that generates glyphs for
 marginal areas.

src/ChangeLog

+2014-05-25  Eli Zaretskii  <eliz@gnu.org>
+
+	* xdisp.c (move_it_in_display_line_to): Don't record wrap position
+	if we are iterating over an object that generates glyphs for
+	marginal areas.  (Bug#17585)
+
 2014-05-24  Paul Eggert  <eggert@cs.ucla.edu>
 
 	* xdisp.c (safe__call1, safe__eval): Now static.

src/xdisp.c

@@ -8556,7 +8556,7 @@ move_it_in_display_line_to (struct it *it,
 	}
       else
 	{
-	  if (it->line_wrap == WORD_WRAP)
+	  if (it->line_wrap == WORD_WRAP && it->area == TEXT_AREA)
 	    {
 	      if (IT_DISPLAYING_WHITESPACE (it))
 		may_wrap = 1;