Get rid of the direct_output optimizations.

* keyboard.c (nonundocount): Remove extern declaration.
(command_loop_1): Remove brittle optimisation for cheap and common operations.
* xdisp.c (redisplay_internal): Don't bother checking
redisplay_performed_directly_p any more.
* sysdep.c (init_sys_modes): Don't call direct_output_forward_char any more.
* dispnew.c (redisplay_performed_directly_p)
(direct_output_for_insert, direct_output_forward_char):
* dispextern.h (redisplay_performed_directly_p)
(direct_output_for_insert, direct_output_forward_char): Remove.
* cmds.c (nonundocount): Make it static.

7 files changed, 23 insertions, 602 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 767780d6938..9d70a3327b6 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,19 @@
+2010-03-31  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        Get rid of the direct_output optimizations.
+        * keyboard.c (nonundocount): Remove extern declaration.
+        (command_loop_1): Remove brittle optimisation for cheap and
+        common operations.
+        * xdisp.c (redisplay_internal): Don't bother checking
+        redisplay_performed_directly_p any more.
+        * sysdep.c (init_sys_modes): Don't call direct_output_forward_char
+        any more.
+        * dispnew.c (redisplay_performed_directly_p)
+        (direct_output_for_insert, direct_output_forward_char):
+        * dispextern.h (redisplay_performed_directly_p)
+        (direct_output_for_insert, direct_output_forward_char): Remove.
+        * cmds.c (nonundocount): Make it static.
+
 2010-03-31  Bernhard Herzog  <bh@intevation.de>  (tiny change)
 
         * menu.c (Fx_popup_menu): Use last_event_timestamp (Bug#4930).
@@ -9,8 +25,8 @@
 
 2010-03-31  Adrian Robert  <adrian.b.robert@gmail.com>
 
-        * xdisp.c (x_consider_frame_title, update_window_cursor): Remove
-        HAVE_NS conditionals.
+        * xdisp.c (x_consider_frame_title, update_window_cursor):
+        Remove HAVE_NS conditionals.
         (prepare_menu_bars)[HAVE_NS]: Call ns_set_doc_edited.
 
         * nsfns.m (x_implicitly_set_name): If frame-title-format is t, use
diff --git a/src/cmds.c b/src/cmds.c
index fd337f378bb..5d450fe9a13 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -317,7 +317,7 @@ N was explicitly specified.  */)
   return value;
 }
 
-int nonundocount;
+static int nonundocount;
 
 /* Note that there's code in command_loop_1 which typically avoids
    calling this.  */
diff --git a/src/dispextern.h b/src/dispextern.h
index 5083199c529..b8f68ec0e70 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -1102,17 +1102,9 @@ extern int cursor_in_echo_area;
 
 extern int display_completed;
 
-/* Non-zero means redisplay has been performed directly (see also
-   direct_output_for_insert and direct_output_forward_char), so that
-   no further updating has to be performed.  The function
-   redisplay_internal checks this flag, and does nothing but reset it
-   to zero if it is non-zero.  */
-
-extern int redisplay_performed_directly_p;
-
 /* A temporary storage area, including a row of glyphs.  Initialized
    in xdisp.c.  Used for various purposes, as an example see
-   direct_output_for_insert.  */
+   get_overlay_arrow_glyph_row.  */
 
 extern struct glyph_row scratch_glyph_row;
 
@@ -3172,8 +3164,6 @@ extern void redraw_garbaged_frames P_ ((void));
 extern void cancel_line P_ ((int, struct frame *));
 extern void init_desired_glyphs P_ ((struct frame *));
 extern int scroll_frame_lines P_ ((struct frame *, int, int, int, int));
-extern int direct_output_for_insert P_ ((int));
-extern int direct_output_forward_char P_ ((int));
 extern int update_frame P_ ((struct frame *, int, int));
 extern int scrolling P_ ((struct frame *));
 extern void bitch_at_user P_ ((void));
@@ -3200,8 +3190,6 @@ void set_window_update_flags P_ ((struct window *, int));
 void redraw_frame P_ ((struct frame *));
 void redraw_garbaged_frames P_ ((void));
 int scroll_cost P_ ((struct frame *, int, int, int));
-int direct_output_for_insert P_ ((int));
-int direct_output_forward_char P_ ((int));
 int update_frame P_ ((struct frame *, int, int));
 void update_single_window P_ ((struct window *, int));
 int scrolling P_ ((struct frame *));
diff --git a/src/dispnew.c b/src/dispnew.c
index fd470491f78..52d7f38728f 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -302,12 +302,6 @@ int updated_area;
 
 struct glyph space_glyph;
 
-/* Non-zero means update has been performed directly, so that there's
-   no need for redisplay_internal to do much work.  Set by
-   direct_output_for_insert.  */
-
-int redisplay_performed_directly_p;
-
 /* Counts of allocated structures.  These counts serve to diagnose
    memory leaks and double frees.  */
 
@@ -3456,401 +3450,6 @@ redraw_garbaged_frames ()
 
 
 /***********************************************************************
-                          Direct Operations
- ***********************************************************************/
-
-/* Try to update display and current glyph matrix directly.
-
-   This function is called after a character G has been inserted into
-   current_buffer.  It tries to update the current glyph matrix and
-   perform appropriate screen output to reflect the insertion.  If it
-   succeeds, the global flag redisplay_performed_directly_p will be
-   set to 1, and thereby prevent the more costly general redisplay
-   from running (see redisplay_internal).
-
-   This function is not called for `hairy' character insertions.
-   In particular, it is not called when after or before change
-   functions exist, like they are used by font-lock.  See keyboard.c
-   for details where this function is called.  */
-
-int
-direct_output_for_insert (g)
-     int g;
-{
-  register struct frame *f = SELECTED_FRAME ();
-  struct window *w = XWINDOW (selected_window);
-  struct it it, it2;
-  struct glyph_row *glyph_row;
-  struct glyph *glyphs, *glyph, *end;
-  int n;
-  /* Non-null means that redisplay of W is based on window matrices.  */
-  int window_redisplay_p = FRAME_WINDOW_P (f);
-  /* Non-null means we are in overwrite mode.  */
-  int overwrite_p = !NILP (current_buffer->overwrite_mode);
-  int added_width;
-  struct text_pos pos;
-  int delta, delta_bytes;
-
-  /* Not done directly.  */
-  redisplay_performed_directly_p = 0;
-
-  /* Quickly give up for some common cases.  */
-  if (cursor_in_echo_area
-      /* Give up if fonts have changed.  */
-      || fonts_changed_p
-      /* Give up if face attributes have been changed.  */
-      || face_change_count
-      /* Give up if cursor position not really known.  */
-      || !display_completed
-      /* Give up if buffer appears in two places.  */
-      || buffer_shared > 1
-      /* Give up if we need to reorder bidirectional text.  */
-      || !NILP (current_buffer->bidi_display_reordering)
-      /* Give up if currently displaying a message instead of the
-         minibuffer contents.  */
-      || (EQ (selected_window, minibuf_window)
-          && EQ (minibuf_window, echo_area_window))
-      /* Give up for hscrolled mini-buffer because display of the prompt
-         is handled specially there (see display_line).  */
-      || (MINI_WINDOW_P (w) && XFASTINT (w->hscroll))
-      /* Give up if overwriting in the middle of a line.  */
-      || (overwrite_p
-          && PT != ZV
-          && FETCH_BYTE (PT) != '\n')
-      /* Give up for tabs and line ends.  */
-      || g == '\t'
-      || g == '\n'
-      || g == '\r'
-      || (g == ' ' && !NILP (current_buffer->word_wrap))
-      /* Give up if unable to display the cursor in the window.  */
-      || w->cursor.vpos < 0
-      /* Give up if we are showing a message or just cleared the message
-         because we might need to resize the echo area window.  */
-      || !NILP (echo_area_buffer[0])
-      || !NILP (echo_area_buffer[1])
-      || (glyph_row = MATRIX_ROW (w->current_matrix, w->cursor.vpos),
-          /* Can't do it in a continued line because continuation
-             lines would change.  */
-          (glyph_row->continued_p
-           || glyph_row->exact_window_width_line_p
-           /* Can't use this method if the line overlaps others or is
-              overlapped by others because these other lines would
-              have to be redisplayed.  */
-           || glyph_row->overlapping_p
-           || glyph_row->overlapped_p))
-      /* Can't do it for partial width windows on terminal frames
-         because we can't clear to eol in such a window.  */
-      || (!window_redisplay_p && !WINDOW_FULL_WIDTH_P (w)))
-    return 0;
-
-  /* If we can't insert glyphs, we can use this method only
-     at the end of a line.  */
-  if (!FRAME_CHAR_INS_DEL_OK (f))
-    if (PT != ZV && FETCH_BYTE (PT_BYTE) != '\n')
-      return 0;
-
-  /* Set up a display iterator structure for W.  Glyphs will be
-     produced in scratch_glyph_row.  Current position is W's cursor
-     position.  */
-  clear_glyph_row (&scratch_glyph_row);
-  SET_TEXT_POS (pos, PT, PT_BYTE);
-  DEC_TEXT_POS (pos, !NILP (current_buffer->enable_multibyte_characters));
-  init_iterator (&it, w, CHARPOS (pos), BYTEPOS (pos), &scratch_glyph_row,
-                 DEFAULT_FACE_ID);
-
-  glyph_row = MATRIX_ROW (w->current_matrix, w->cursor.vpos);
-  if (glyph_row->mouse_face_p)
-    return 0;
-
-  /* Give up if highlighting trailing whitespace and we have trailing
-     whitespace in glyph_row.  We would have to remove the trailing
-     whitespace face in that case.  */
-  if (!NILP (Vshow_trailing_whitespace)
-      && glyph_row->used[TEXT_AREA])
-    {
-      struct glyph *last;
-
-      last = glyph_row->glyphs[TEXT_AREA] + glyph_row->used[TEXT_AREA] - 1;
-      if (last->type == STRETCH_GLYPH
-          || (last->type == CHAR_GLYPH
-              && last->u.ch == ' '))
-        return 0;
-    }
-
-  /* Give up if there are overlay strings at pos.  This would fail
-     if the overlay string has newlines in it.  */
-  if (STRINGP (it.string))
-    return 0;
-
-  it.hpos = w->cursor.hpos;
-  it.vpos = w->cursor.vpos;
-  it.current_x = w->cursor.x + it.first_visible_x;
-  it.current_y = w->cursor.y;
-  it.end_charpos = PT;
-  it.stop_charpos = min (PT, it.stop_charpos);
-  it.stop_charpos = max (IT_CHARPOS (it), it.stop_charpos);
-
-  /* More than one display element may be returned for PT - 1 if
-     (i) it's a control character which is translated into `\003' or
-     `^C', or (ii) it has a display table entry, or (iii) it's a
-     combination of both.  */
-  delta = delta_bytes = 0;
-  while (get_next_display_element (&it))
-    {
-      PRODUCE_GLYPHS (&it);
-
-      /* Give up if glyph doesn't fit completely on the line.  */
-      if (it.current_x >= it.last_visible_x)
-        return 0;
-
-      /* Give up if new glyph has different ascent or descent than
-         the original row, or if it is not a character glyph.  */
-      if (glyph_row->ascent != it.ascent
-          || glyph_row->height != it.ascent + it.descent
-          || glyph_row->phys_ascent != it.phys_ascent
-          || glyph_row->phys_height != it.phys_ascent + it.phys_descent
-          || it.what != IT_CHARACTER)
-        return 0;
-
-      delta += 1;
-      delta_bytes += it.len;
-      set_iterator_to_next (&it, 1);
-    }
-
-  /* Give up if we hit the right edge of the window.  We would have
-     to insert truncation or continuation glyphs.  */
-  added_width = it.current_x - (w->cursor.x + it.first_visible_x);
-  if (glyph_row->pixel_width + added_width >= it.last_visible_x)
-    return 0;
-
-  /* Give up if there is a \t following in the line.  */
-  it2 = it;
-  it2.end_charpos = ZV;
-  it2.stop_charpos = min (it2.stop_charpos, ZV);
-  while (get_next_display_element (&it2)
-         && !ITERATOR_AT_END_OF_LINE_P (&it2))
-    {
-      if (it2.c == '\t')
-        return 0;
-      set_iterator_to_next (&it2, 1);
-    }
-
-  /* Number of new glyphs produced.  */
-  n = it.glyph_row->used[TEXT_AREA];
-
-  /* Start and end of glyphs in original row.  */
-  glyphs = glyph_row->glyphs[TEXT_AREA] + w->cursor.hpos;
-  end = glyph_row->glyphs[1 + TEXT_AREA];
-
-  /* Make room for new glyphs, then insert them.  */
-  xassert (end - glyphs - n >= 0);
-  safe_bcopy ((char *) glyphs, (char *) (glyphs + n),
-              (end - glyphs - n) * sizeof (*end));
-  bcopy (it.glyph_row->glyphs[TEXT_AREA], glyphs, n * sizeof *glyphs);
-  glyph_row->used[TEXT_AREA] = min (glyph_row->used[TEXT_AREA] + n,
-                                    end - glyph_row->glyphs[TEXT_AREA]);
-
-  /* Compute new line width.  */
-  glyph = glyph_row->glyphs[TEXT_AREA];
-  end = glyph + glyph_row->used[TEXT_AREA];
-  glyph_row->pixel_width = glyph_row->x;
-  while (glyph < end)
-    {
-      glyph_row->pixel_width += glyph->pixel_width;
-      ++glyph;
-    }
-
-  /* Increment buffer positions for glyphs following the newly
-     inserted ones.  */
-  for (glyph = glyphs + n; glyph < end; ++glyph)
-    if (glyph->charpos > 0 && BUFFERP (glyph->object))
-      glyph->charpos += delta;
-
-  if (MATRIX_ROW_END_CHARPOS (glyph_row) > 0)
-    {
-      MATRIX_ROW_END_CHARPOS (glyph_row) += delta;
-      MATRIX_ROW_END_BYTEPOS (glyph_row) += delta_bytes;
-    }
-
-  /* Adjust positions in lines following the one we are in.  */
-  increment_matrix_positions (w->current_matrix,
-                              w->cursor.vpos + 1,
-                              w->current_matrix->nrows,
-                              delta, delta_bytes);
-
-  glyph_row->contains_overlapping_glyphs_p
-    |= it.glyph_row->contains_overlapping_glyphs_p;
-
-  glyph_row->displays_text_p = 1;
-  w->window_end_vpos = make_number (max (w->cursor.vpos,
-                                         XFASTINT (w->window_end_vpos)));
-
-  if (!NILP (Vshow_trailing_whitespace))
-    highlight_trailing_whitespace (it.f, glyph_row);
-
-  /* Write glyphs.  If at end of row, we can simply call write_glyphs.
-     In the middle, we have to insert glyphs.  Note that this is now
-     implemented for X frames.  The implementation uses updated_window
-     and updated_row.  */
-  updated_row = glyph_row;
-  updated_area = TEXT_AREA;
-  update_begin (f);
-  if (FRAME_RIF (f))
-    {
-      FRAME_RIF (f)->update_window_begin_hook (w);
-
-      if (glyphs == end - n
-          /* In front of a space added by append_space.  */
-          || (glyphs == end - n - 1
-              && (end - n)->charpos <= 0))
-        FRAME_RIF (f)->write_glyphs (glyphs, n);
-      else
-        FRAME_RIF (f)->insert_glyphs (glyphs, n);
-    }
-  else
-    {
-      if (glyphs == end - n)
-        write_glyphs (f, glyphs, n);
-      else
-        insert_glyphs (f, glyphs, n);
-    }
-
-  w->cursor.hpos += n;
-  w->cursor.x = it.current_x - it.first_visible_x;
-  xassert (w->cursor.hpos >= 0
-           && w->cursor.hpos < w->desired_matrix->matrix_w);
-
-  /* How to set the cursor differs depending on whether we are
-     using a frame matrix or a window matrix.   Note that when
-     a frame matrix is used, cursor_to expects frame coordinates,
-     and the X and Y parameters are not used.  */
-  if (window_redisplay_p)
-    FRAME_RIF (f)->cursor_to (w->cursor.vpos, w->cursor.hpos,
-                              w->cursor.y, w->cursor.x);
-  else
-    {
-      int x, y;
-      x = (WINDOW_TO_FRAME_HPOS (w, w->cursor.hpos)
-           + (INTEGERP (w->left_margin_cols)
-              ? XFASTINT (w->left_margin_cols)
-              : 0));
-      y = WINDOW_TO_FRAME_VPOS (w, w->cursor.vpos);
-      cursor_to (f, y, x);
-    }
-
-#ifdef HAVE_WINDOW_SYSTEM
-  update_window_fringes (w, 0);
-#endif
-
-  if (FRAME_RIF (f))
-    FRAME_RIF (f)->update_window_end_hook (w, 1, 0);
-  update_end (f);
-  updated_row = NULL;
-  if (FRAME_TERMCAP_P (f))
-    fflush (FRAME_TTY (f)->output);
-
-  TRACE ((stderr, "direct output for insert\n"));
-  mark_window_display_accurate (it.window, 1);
-  redisplay_performed_directly_p = 1;
-  return 1;
-}
-
-
-/* Perform a direct display update for moving PT by N positions
-   left or right.  N < 0 means a movement backwards.  This function
-   is currently only called for N == 1 or N == -1.  */
-
-int
-direct_output_forward_char (n)
-     int n;
-{
-  struct frame *f = SELECTED_FRAME ();
-  struct window *w = XWINDOW (selected_window);
-  struct glyph_row *row;
-
-  /* Give up if point moved out of or into a composition.  */
-  if (check_point_in_composition (current_buffer, XINT (w->last_point),
-                                  current_buffer, PT))
-    return 0;
-
-  /* Give up if face attributes have been changed.  */
-  if (face_change_count)
-    return 0;
-
-  /* Give up if current matrix is not up to date or we are
-     displaying a message.  */
-  if (!display_completed || cursor_in_echo_area)
-    return 0;
-
-  /* Give up if we need to reorder bidirectional text.  */
-  if (!NILP (XBUFFER (w->buffer)->bidi_display_reordering))
-    return 0;
-
-  /* Give up if the buffer's direction is reversed.  */
-  if (!NILP (XBUFFER (w->buffer)->direction_reversed))
-    return 0;
-
-  /* Can't use direct output if highlighting a region.  */
-  if (!NILP (Vtransient_mark_mode) && !NILP (current_buffer->mark_active))
-    return 0;
-
-  /* Can't use direct output if highlighting trailing whitespace.  */
-  if (!NILP (Vshow_trailing_whitespace))
-    return 0;
-
-  /* Give up if we are showing a message or just cleared the message
-     because we might need to resize the echo area window.  */
-  if (!NILP (echo_area_buffer[0]) || !NILP (echo_area_buffer[1]))
-    return 0;
-
-  /* Give up if currently displaying a message instead of the
-     minibuffer contents.  */
-  if (XWINDOW (minibuf_window) == w
-      && EQ (minibuf_window, echo_area_window))
-    return 0;
-
-  /* Give up if we don't know where the cursor is.  */
-  if (w->cursor.vpos < 0)
-    return 0;
-
-  row = MATRIX_ROW (w->current_matrix, w->cursor.vpos);
-
-  /* Give up if PT is outside of the last known cursor row.  */
-  if (PT <= MATRIX_ROW_START_CHARPOS (row)
-      || PT >= MATRIX_ROW_END_CHARPOS (row))
-    return 0;
-
-  set_cursor_from_row (w, row, w->current_matrix, 0, 0, 0, 0);
-
-  w->last_cursor = w->cursor;
-  XSETFASTINT (w->last_point, PT);
-
-  xassert (w->cursor.hpos >= 0
-           && w->cursor.hpos < w->desired_matrix->matrix_w);
-
-  if (FRAME_WINDOW_P (f))
-    FRAME_RIF (f)->cursor_to (w->cursor.vpos, w->cursor.hpos,
-                              w->cursor.y, w->cursor.x);
-  else
-    {
-      int x, y;
-      x = (WINDOW_TO_FRAME_HPOS (w, w->cursor.hpos)
-           + (INTEGERP (w->left_margin_cols)
-              ? XFASTINT (w->left_margin_cols)
-              : 0));
-      y = WINDOW_TO_FRAME_VPOS (w, w->cursor.vpos);
-      cursor_to (f, y, x);
-    }
-
-  if (FRAME_TERMCAP_P (f))
-    fflush (FRAME_TTY (f)->output);
-  redisplay_performed_directly_p = 1;
-  return 1;
-}
-
-
-
-/***********************************************************************
                              Frame Update
  ***********************************************************************/
 
diff --git a/src/keyboard.c b/src/keyboard.c
index f6d6704b373..3cd042fb21e 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -1520,8 +1520,6 @@ cancel_hourglass_unwind (arg)
 }
 #endif
 
-extern int nonundocount;        /* Declared in cmds.c.  */
-
 Lisp_Object
 command_loop_1 ()
 {
@@ -1744,149 +1742,8 @@ command_loop_1 ()
         }
       else
         {
-          if (NILP (current_kboard->Vprefix_arg))
-            {
-              /* In case we jump to directly_done.  */
-              Vcurrent_prefix_arg = current_kboard->Vprefix_arg;
-
-              /* Recognize some common commands in common situations and
-                 do them directly.  */
-              if (EQ (Vthis_command, Qforward_char) && PT < ZV
-                  && NILP (Vthis_command_keys_shift_translated)
-                  && !CONSP (Vtransient_mark_mode))
-                {
-                  struct Lisp_Char_Table *dp
-                    = window_display_table (XWINDOW (selected_window));
-                  lose = FETCH_CHAR (PT_BYTE);
-                  SET_PT (PT + 1);
-                  if (! NILP (Vpost_command_hook))
-                    /* Put this before calling adjust_point_for_property
-                       so it will only get called once in any case.  */
-                    goto directly_done;
-                  if (current_buffer == prev_buffer
-                      && last_point_position != PT
-                      && NILP (Vdisable_point_adjustment)
-                      && NILP (Vglobal_disable_point_adjustment))
-                    adjust_point_for_property (last_point_position, 0);
-                  already_adjusted = 1;
-                  if (PT == last_point_position + 1
-                      && (dp
-                          ? (VECTORP (DISP_CHAR_VECTOR (dp, lose))
-                             ? XVECTOR (DISP_CHAR_VECTOR (dp, lose))->size == 1
-                             : (NILP (DISP_CHAR_VECTOR (dp, lose))
-                                && (lose >= 0x20 && lose < 0x7f)))
-                          : (lose >= 0x20 && lose < 0x7f))
-                      /* To extract the case of continuation on
-                         wide-column characters.  */
-                      && ASCII_BYTE_P (lose)
-                      && (XFASTINT (XWINDOW (selected_window)->last_modified)
-                          >= MODIFF)
-                      && (XFASTINT (XWINDOW (selected_window)->last_overlay_modified)
-                          >= OVERLAY_MODIFF)
-                      && (XFASTINT (XWINDOW (selected_window)->last_point)
-                          == PT - 1)
-                      && !windows_or_buffers_changed
-                      && EQ (current_buffer->selective_display, Qnil)
-                      && !detect_input_pending ()
-                      && NILP (XWINDOW (selected_window)->column_number_displayed)
-                      && NILP (Vexecuting_kbd_macro))
-                    direct_output_forward_char (1);
-                  goto directly_done;
-                }
-              else if (EQ (Vthis_command, Qbackward_char) && PT > BEGV
-                       && NILP (Vthis_command_keys_shift_translated)
-                       && !CONSP (Vtransient_mark_mode))
-                {
-                  struct Lisp_Char_Table *dp
-                    = window_display_table (XWINDOW (selected_window));
-                  SET_PT (PT - 1);
-                  lose = FETCH_CHAR (PT_BYTE);
-                  if (! NILP (Vpost_command_hook))
-                    goto directly_done;
-                  if (current_buffer == prev_buffer
-                      && last_point_position != PT
-                      && NILP (Vdisable_point_adjustment)
-                      && NILP (Vglobal_disable_point_adjustment))
-                    adjust_point_for_property (last_point_position, 0);
-                  already_adjusted = 1;
-                  if (PT == last_point_position - 1
-                      && (dp
-                          ? (VECTORP (DISP_CHAR_VECTOR (dp, lose))
-                             ? XVECTOR (DISP_CHAR_VECTOR (dp, lose))->size == 1
-                             : (NILP (DISP_CHAR_VECTOR (dp, lose))
-                                && (lose >= 0x20 && lose < 0x7f)))
-                          : (lose >= 0x20 && lose < 0x7f))
-                      && (XFASTINT (XWINDOW (selected_window)->last_modified)
-                          >= MODIFF)
-                      && (XFASTINT (XWINDOW (selected_window)->last_overlay_modified)
-                          >= OVERLAY_MODIFF)
-                      && (XFASTINT (XWINDOW (selected_window)->last_point)
-                          == PT + 1)
-                      && !windows_or_buffers_changed
-                      && EQ (current_buffer->selective_display, Qnil)
-                      && !detect_input_pending ()
-                      && NILP (XWINDOW (selected_window)->column_number_displayed)
-                      && NILP (Vexecuting_kbd_macro))
-                    direct_output_forward_char (-1);
-                  goto directly_done;
-                }
-              else if (EQ (Vthis_command, Qself_insert_command)
-                       /* Try this optimization only on char keystrokes.  */
-                       && NATNUMP (last_command_event)
-                       && CHAR_VALID_P (XFASTINT (last_command_event), 0))
-                {
-                  unsigned int c
-                    = translate_char (Vtranslation_table_for_input,
-                                      XFASTINT (last_command_event));
-                  int value;
-                  if (NILP (Vexecuting_kbd_macro)
-                      && !EQ (minibuf_window, selected_window))
-                    {
-                      if (!nonundocount || nonundocount >= 20)
-                        {
-                          Fundo_boundary ();
-                          nonundocount = 0;
-                        }
-                      nonundocount++;
-                    }
-
-                  lose = ((XFASTINT (XWINDOW (selected_window)->last_modified)
-                           < MODIFF)
-                          || (XFASTINT (XWINDOW (selected_window)->last_overlay_modified)
-                              < OVERLAY_MODIFF)
-                          || (XFASTINT (XWINDOW (selected_window)->last_point)
-                              != PT)
-                          || MODIFF <= SAVE_MODIFF
-                          || windows_or_buffers_changed
-                          || !EQ (current_buffer->selective_display, Qnil)
-                          || detect_input_pending ()
-                          || !NILP (XWINDOW (selected_window)->column_number_displayed)
-                          || !NILP (Vexecuting_kbd_macro));
-
-                  value = internal_self_insert (c, 0);
-
-                  if (value == 2)
-                    nonundocount = 0;
-
-                  frame_make_pointer_invisible ();
-
-                  if (! NILP (Vpost_command_hook))
-                    /* Put this before calling adjust_point_for_property
-                       so it will only get called once in any case.  */
-                    goto directly_done;
-
-                  /* VALUE == 1 when AFTER-CHANGE functions are
-                     installed which is the case most of the time
-                     because FONT-LOCK installs one.  */
-                  if (!lose && !value)
-                    direct_output_for_insert (c);
-                  goto directly_done;
-                }
-            }
-
           /* Here for a command that isn't executed directly */
 
-          {
 #ifdef HAVE_WINDOW_SYSTEM
             int scount = SPECPDL_INDEX ();
 
@@ -1898,7 +1755,6 @@ command_loop_1 ()
               }
 #endif
 
-            nonundocount = 0;
             if (NILP (current_kboard->Vprefix_arg)) /* FIXME: Why?  --Stef  */
               Fundo_boundary ();
             Fcommand_execute (Vthis_command, Qnil, Qnil, Qnil);
@@ -1913,8 +1769,6 @@ command_loop_1 ()
             unbind_to (scount, Qnil);
 #endif
           }
-        }
-    directly_done: ;
       current_kboard->Vlast_prefix_arg = Vcurrent_prefix_arg;
 
       /* Note that the value cell will never directly contain nil
diff --git a/src/sysdep.c b/src/sysdep.c
index 2f79a711cfd..73209b03c08 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -1401,9 +1401,8 @@ init_sys_modes (tty_out)
 
   if (tty_out->term_initted && no_redraw_on_reenter)
     {
-      /* XXX This seems wrong on multi-tty. */
-      if (display_completed)
-        direct_output_forward_char (0);
+      /* We used to call "direct_output_forward_char(0)" here,
+         but it's not clear why, since it may not do anything anyway.  */
     }
   else
     {
diff --git a/src/xdisp.c b/src/xdisp.c
index b6c69f661ed..b3aaa52e2e5 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -32,9 +32,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    decides it's time to do it.  This is done either automatically for
    you as part of the interpreter's command loop or as the result of
    calling Lisp functions like `sit-for'.  The C function `redisplay'
-   in xdisp.c is the only entry into the inner redisplay code.  (Or,
-   let's say almost---see the description of direct update
-   operations, below.)
+   in xdisp.c is the only entry into the inner redisplay code.
 
    The following diagram shows how redisplay code is invoked.  As you
    can see, Lisp calls redisplay and vice versa.  Under window systems
@@ -46,12 +44,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    change the interpreter's state.  If you don't follow these rules,
    you will encounter bugs which are very hard to explain.
 
-             (Direct functions, see below)
-             direct_output_for_insert,
-             direct_forward_char (dispnew.c)
-          +---------------------------------+
-          |                                 |
-          |                                 V
    +--------------+   redisplay     +----------------+
    | Lisp machine |---------------->| Redisplay code |<--+
    +--------------+   (xdisp.c)     +----------------+   |
@@ -85,28 +77,11 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    then compared to find a cheap way to update the display, e.g. by
    reusing part of the display by scrolling lines.
 
-
-   Direct operations.
-
    You will find a lot of redisplay optimizations when you start
    looking at the innards of redisplay.  The overall goal of all these
    optimizations is to make redisplay fast because it is done
    frequently.
 
-   Two optimizations are not found in xdisp.c.  These are the direct
-   operations mentioned above.  As the name suggests they follow a
-   different principle than the rest of redisplay.  Instead of
-   building a desired matrix and then comparing it with the current
-   display, they perform their actions directly on the display and on
-   the current matrix.
-
-   One direct operation updates the display after one character has
-   been entered.  The other one moves the cursor by one position
-   forward or backward.  You find these functions under the names
-   `direct_output_for_insert' and `direct_output_forward_char' in
-   dispnew.c.
-
-
    Desired matrices.
 
    Desired matrices are always built per Emacs window.  The function
@@ -11618,16 +11593,6 @@ redisplay_internal (preserve_echo_area)
   if (!f->glyphs_initialized_p)
     return;
 
-  /* The flag redisplay_performed_directly_p is set by
-     direct_output_for_insert when it already did the whole screen
-     update necessary.  */
-  if (redisplay_performed_directly_p)
-    {
-      redisplay_performed_directly_p = 0;
-      if (!hscroll_windows (selected_window))
-        return;
-    }
-
 #if defined (USE_X_TOOLKIT) || defined (USE_GTK) || defined (HAVE_NS)
   if (popup_activated ())
     return;