(redisplay): do_verify_charstarts controls whether to call verify_charstarts.

Fix one-off when checking for the last line.

diff --git a/src/xdisp.c b/src/xdisp.c
index 93ca88b4bdbfc8ebcdbd2d987d1f66e2d4ffb562..a00b529361987e72937af4f670ab8a97f03cbc86 100644 (file)
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -505,6 +505,8 @@ prepare_menu_bars ()
    See Fcall_process; if you called it from here, it could be
    entered recursively.  */
 
+static int do_verify_charstarts;
+
 void
 redisplay ()
 {
@@ -623,7 +625,10 @@ redisplay ()
          if (cursor_vpos >= 0 && this_line_bufpos
              && this_line_endpos == tlendpos)
            {
-             if (this_line_vpos < XFASTINT (w->top) + window_internal_height (w))
+             /* If this is not the window's last line,
+                we must adjust the charstarts of the lines below.  */
+             if (this_line_vpos + 1
+                 < XFASTINT (w->top) + window_internal_height (w))
                {
                  int left = XFASTINT (w->left);
                  int *charstart_next_line
@@ -832,7 +837,8 @@ update:
          w->window_end_valid = Qt;
          last_arrow_position = Voverlay_arrow_position;
          last_arrow_string = Voverlay_arrow_string;
-         verify_charstarts (w);
+         if (do_verify_charstarts)
+           verify_charstarts (w);
          if (frame_up_to_date_hook != 0)
            (*frame_up_to_date_hook) (selected_frame);
        }
@@ -1601,7 +1607,14 @@ try_window_id (window)
          blank_end_of_window = 1;
        }
       else if (!scroll_amount)
-       {}
+       {
+         /* Even if we don't need to scroll, we must adjust the
+            charstarts of subsequent lines (that we won't redisplay)
+            according to the amount of text inserted or deleted.  */
+         int oldpos = FRAME_CURRENT_GLYPHS (f)->charstarts[ep.vpos + top][0];
+         int adjust = ep.bufpos - oldpos;
+         adjust_window_charstarts (w, ep.vpos + top - 1, adjust);
+       }
       else if (bp.bufpos == Z - end_unchanged)
        {
          /* If reprinting everything is nearly as fast as scrolling,