Avoid overwriting the reversed_p flags in the glyph matrices.

 Avoid overwriting the reversed_p flags in the glyph matrices when
 init_iterator or start_display are called.

 src/xdisp.c (init_iterator): Don't initialize the reversed_p flag of
 the glyph row here.
 (tool_bar_height, redisplay_tool_bar, try_window)
 (try_window_reusing_current_matrix, try_window_id)
 (get_overlay_arrow_glyph_row, display_menu_bar): Initialize the
 reversed_p flag of the iterator's glyph row where the glyph row
 is going to be redrawn.

2 files changed, 23 insertions, 4 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 3c10f66aaac..3d04357af59 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,15 @@
+2014-08-17  Eli Zaretskii  <eliz@gnu.org>
+
+        Avoid overwriting the reversed_p flags in the glyph matrices when
+        init_iterator or start_display are called.
+        * xdisp.c (init_iterator): Don't initialize the reversed_p flag of
+        the glyph row here.
+        (tool_bar_height, redisplay_tool_bar, try_window)
+        (try_window_reusing_current_matrix, try_window_id)
+        (get_overlay_arrow_glyph_row, display_menu_bar): Initialize the
+        reversed_p flag of the iterator's glyph row where the glyph row
+        is going to be redrawn.
+
 2014-08-16  Paul Eggert  <eggert@cs.ucla.edu>
 
         * xdisp.c (set_horizontal_scroll_bar): Don't use uninitialized local.
diff --git a/src/xdisp.c b/src/xdisp.c
index 7553881b1f6..e7c3e922cb9 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -2971,10 +2971,6 @@ init_iterator (struct it *it, struct window *w,
   it->glyph_row = row;
   it->area = TEXT_AREA;
 
-  /* Forget any previous info about this row being reversed.  */
-  if (it->glyph_row)
-    it->glyph_row->reversed_p = 0;
-
   /* Get the dimensions of the display area.  The display area
      consists of the visible window area plus a horizontally scrolled
      part to the left of the window.  All x-values are relative to the
@@ -12294,6 +12290,7 @@ tool_bar_height (struct frame *f, int *n_rows, bool pixelwise)
   /* Initialize an iterator for iteration over
      F->desired_tool_bar_string in the tool-bar window of frame F.  */
   init_iterator (&it, w, -1, -1, temp_row, TOOL_BAR_FACE_ID);
+  temp_row->reversed_p = false;
   it.first_visible_x = 0;
   it.last_visible_x = WINDOW_PIXEL_WIDTH (w);
   reseat_to_string (&it, NULL, f->desired_tool_bar_string, 0, 0, 0, -1);
@@ -12378,6 +12375,7 @@ redisplay_tool_bar (struct frame *f)
   it.first_visible_x = 0;
   it.last_visible_x = WINDOW_PIXEL_WIDTH (w);
   row = it.glyph_row;
+  row->reversed_p = false;
 
   /* Build a string that represents the contents of the tool-bar.  */
   build_desired_tool_bar_string (f);
@@ -16898,6 +16896,7 @@ try_window (Lisp_Object window, struct text_pos pos, int flags)
 
   /* Initialize iterator and info to start at POS.  */
   start_display (&it, w, pos);
+  it.glyph_row->reversed_p = false;
 
   /* Display all lines of W.  */
   while (it.current_y < it.last_visible_y)
@@ -17081,6 +17080,7 @@ try_window_reusing_current_matrix (struct window *w)
               && it.current.dpvec_index < 0)
             break;
 
+          it.glyph_row->reversed_p = false;
           if (display_line (&it))
             last_text_row = it.glyph_row - 1;
 
@@ -18101,6 +18101,11 @@ try_window_id (struct window *w)
   w->cursor.vpos = -1;
   last_text_row = NULL;
   overlay_arrow_seen = 0;
+  if (it.current_y < it.last_visible_y
+      && !f->fonts_changed
+      && (first_unchanged_at_end_row == NULL
+          || IT_CHARPOS (it) < stop_pos))
+    it.glyph_row->reversed_p = false;
   while (it.current_y < it.last_visible_y
          && !f->fonts_changed
          && (first_unchanged_at_end_row == NULL
@@ -18810,6 +18815,7 @@ get_overlay_arrow_glyph_row (struct window *w, Lisp_Object overlay_arrow_string)
 
   set_buffer_temp (buffer);
   init_iterator (&it, w, -1, -1, &scratch_glyph_row, DEFAULT_FACE_ID);
+  scratch_glyph_row.reversed_p = false;
   it.glyph_row->used[TEXT_AREA] = 0;
   SET_TEXT_POS (it.position, 0, 0);
 
@@ -21400,6 +21406,7 @@ display_menu_bar (struct window *w)
       clear_glyph_row (row);
       row->enabled_p = true;
       row->full_width_p = 1;
+      row->reversed_p = false;
     }
 
   /* Display all items of the menu bar.  */