Fix vertical-motion and posn-at-point when word-wrap is on (Bug#19769)

 src/xdisp.c (move_it_in_display_line_to): Handle the case where the
 last character of a screen line is whitespace, and we are under
 word-wrap with overflow-newline-into-fringe turned on.

2 files changed, 37 insertions, 2 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 8e7ab9363f6..135f28fb20f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2015-02-05  Eli Zaretskii  <eliz@gnu.org>
+
+	* xdisp.c (move_it_in_display_line_to): Handle the case where the
+	last character of a screen line is whitespace, and we are under
+	word-wrap with overflow-newline-into-fringe turned on.
+	(Bug#19769)
+
 2015-02-03  Eli Zaretskii  <eliz@gnu.org>
 
 	* xdisp.c (handle_stop, handle_single_display_spec)
diff --git a/src/xdisp.c b/src/xdisp.c
index 5e552ca2fdb..8cb43538dcc 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -8798,7 +8798,16 @@ move_it_in_display_line_to (struct it *it,
 			  if (BUFFER_POS_REACHED_P ())
 			    {
 			      if (it->line_wrap != WORD_WRAP
-				  || wrap_it.sp < 0)
+				  || wrap_it.sp < 0
+				  /* If we've just found whitespace to
+				     wrap, effectively ignore the
+				     previous wrap point -- it is no
+				     longer relevant, but we won't
+				     have an opportunity to update it,
+				     since we've reached the edge of
+				     this screen line.  */
+				  || (may_wrap
+				      && IT_OVERFLOW_NEWLINE_INTO_FRINGE (it)))
 				{
 				  it->hpos = hpos_before_this_char;
 				  it->current_x = x_before_this_char;
@@ -8862,7 +8871,26 @@ move_it_in_display_line_to (struct it *it,
 		  else
 		    IT_RESET_X_ASCENT_DESCENT (it);
 
-		  if (wrap_it.sp >= 0)
+		  /* If the screen line ends with whitespace, and we
+		     are under word-wrap, don't use wrap_it: it is no
+		     longer relevant, but we won't have an opportunity
+		     to update it, since we are done with this screen
+		     line.  */
+		  if (may_wrap && IT_OVERFLOW_NEWLINE_INTO_FRINGE (it))
+		    {
+		      /* If we've found TO_X, go back there, as we now
+			 know the last word fits on this screen line.  */
+		      if ((op & MOVE_TO_X) && new_x == it->last_visible_x
+			  && atx_it.sp >= 0)
+			{
+			  RESTORE_IT (it, &atx_it, atx_data);
+			  atpos_it.sp = -1;
+			  atx_it.sp = -1;
+			  result = MOVE_X_REACHED;
+			  break;
+			}
+		    }
+		  else if (wrap_it.sp >= 0)
 		    {
 		      RESTORE_IT (it, &wrap_it, wrap_data);
 		      atpos_it.sp = -1;