5 files changed, 17 insertions, 33 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index ead50fa0517..6cb69f776f1 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,16 @@
+2013-08-08  Dmitry Antipov  <dmantipov@yandex.ru>
+
+        Do not reset window modification event counters excessively.
+        These leftovers and poor man's tricky methods to catch extra
+        redisplay's attention are no longer needed.
+        * frame.c (set_menu_bar_lines_1):
+        * minibuf.c (read_minibuf_unwind):
+        * window.c (Fset_window_start, set_window_buffer, window_resize_apply)
+        (grow_mini_window, shrink_mini_window, window_scroll_pixel_based)
+        (window_scroll_line_based, Fset_window_configuration):
+        * xdisp.c (redisplay_window): Do not reset last_modified and
+        last_overlay_modified counters.
+
 2013-08-07  Jan Djärv  <jan.h.d@swipnet.se>
 
         * xselect.c (x_send_client_event): Set send_event and serial, memset
diff --git a/src/frame.c b/src/frame.c
index 813c97ffe3e..853ec441343 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -185,7 +185,6 @@ set_menu_bar_lines_1 (Lisp_Object window, int n)
 {
   struct window *w = XWINDOW (window);
 
-  w->last_modified = 0;
   w->top_line += n;
   w->total_lines -= n;
 
diff --git a/src/minibuf.c b/src/minibuf.c
index b3648b8c1ae..7403fc6c32d 100644
--- a/src/minibuf.c
+++ b/src/minibuf.c
@@ -870,10 +870,8 @@ read_minibuf_unwind (void)
   if (minibuf_level == 0)
     resize_mini_window (XWINDOW (window), 0);
 
-  /* Make sure minibuffer window is erased, not ignored.  */
+  /* Enforce full redisplay.  FIXME: make it more selective.  */
   windows_or_buffers_changed++;
-  XWINDOW (window)->last_modified = 0;
-  XWINDOW (window)->last_overlay_modified = 0;
 
   /* In case the previous minibuffer displayed in this miniwindow is
      dead, we may keep displaying this buffer (tho it's inactive), so reset it,
diff --git a/src/window.c b/src/window.c
index 118c5852275..8a514d64954 100644
--- a/src/window.c
+++ b/src/window.c
@@ -1614,9 +1614,8 @@ overriding motion of point in order to display at this exact start.  */)
   if (NILP (noforce))
     w->force_start = 1;
   w->update_mode_line = 1;
-  w->last_modified = 0;
-  w->last_overlay_modified = 0;
   if (!EQ (window, selected_window))
+    /* Enforce full redisplay.  FIXME: make it more selective.  */
     windows_or_buffers_changed++;
 
   return pos;
@@ -3215,8 +3214,6 @@ set_window_buffer (Lisp_Object window, Lisp_Object buffer,
                              buffer);
       w->start_at_line_beg = 0;
       w->force_start = 0;
-      w->last_modified = 0;
-      w->last_overlay_modified = 0;
     }
   /* Maybe we could move this into the `if' but it's not obviously safe and
      I doubt it's worth the trouble.  */
@@ -3677,10 +3674,6 @@ window_resize_apply (struct window *w, bool horflag)
           c = NILP (c->next) ? 0 : XWINDOW (c->next);
         }
     }
-
-  /* Clear out some redisplay caches.  */
-  w->last_modified = 0;
-  w->last_overlay_modified = 0;
 }
 
 
@@ -4199,9 +4192,7 @@ grow_mini_window (struct window *w, int delta)
       /* Grow the mini-window.  */
       w->top_line = r->top_line + r->total_lines;
       w->total_lines -= XINT (value);
-      w->last_modified = 0;
-      w->last_overlay_modified = 0;
-
+      /* Enforce full redisplay.  FIXME: make it more selective.  */
       windows_or_buffers_changed++;
       adjust_glyphs (f);
       unblock_input ();
@@ -4235,10 +4226,7 @@ shrink_mini_window (struct window *w)
           /* Shrink the mini-window.  */
           w->top_line = r->top_line + r->total_lines;
           w->total_lines = 1;
-
-          w->last_modified = 0;
-          w->last_overlay_modified = 0;
-
+          /* Enforce full redisplay.  FIXME: make it more selective.  */
           windows_or_buffers_changed++;
           adjust_glyphs (f);
           unblock_input ();
@@ -4464,8 +4452,6 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, int noerror)
                                          w->contents);
                   w->start_at_line_beg = 1;
                   w->update_mode_line = 1;
-                  w->last_modified = 0;
-                  w->last_overlay_modified = 0;
                   /* Set force_start so that redisplay_window will run the
                      window-scroll-functions.  */
                   w->force_start = 1;
@@ -4610,8 +4596,6 @@ window_scroll_pixel_based (Lisp_Object window, int n, bool whole, int noerror)
       bytepos = marker_byte_position (w->start);
       w->start_at_line_beg = (pos == BEGV || FETCH_BYTE (bytepos - 1) == '\n');
       w->update_mode_line = 1;
-      w->last_modified = 0;
-      w->last_overlay_modified = 0;
       /* Set force_start so that redisplay_window will run the
          window-scroll-functions.  */
       w->force_start = 1;
@@ -4810,8 +4794,6 @@ window_scroll_line_based (Lisp_Object window, int n, bool whole, int noerror)
       set_marker_restricted_both (w->start, w->contents, pos, pos_byte);
       w->start_at_line_beg = !NILP (bolp);
       w->update_mode_line = 1;
-      w->last_modified = 0;
-      w->last_overlay_modified = 0;
       /* Set force_start so that redisplay_window will run
          the window-scroll-functions.  */
       w->force_start = 1;
@@ -5743,9 +5725,6 @@ the return value is nil.  Otherwise the value is t.  */)
                 }
             }
 
-          w->last_modified = 0;
-          w->last_overlay_modified = 0;
-
           if (BUFFERP (p->buffer) && BUFFER_LIVE_P (XBUFFER (p->buffer)))
             /* If saved buffer is alive, install it.  */
             {
diff --git a/src/xdisp.c b/src/xdisp.c
index 102eafbba49..d2dae3406d1 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -15555,8 +15555,6 @@ redisplay_window (Lisp_Object window, int just_this_one_p)
           startp = run_window_scroll_functions (window, startp);
         }
 
-      w->last_modified = 0;
-      w->last_overlay_modified = 0;
       if (CHARPOS (startp) < BEGV)
         SET_TEXT_POS (startp, BEGV, BEGV_BYTE);
       else if (CHARPOS (startp) > ZV)
@@ -15802,9 +15800,6 @@ redisplay_window (Lisp_Object window, int just_this_one_p)
 
  try_to_scroll:
 
-  w->last_modified = 0;
-  w->last_overlay_modified = 0;
-
   /* Redisplay the mode line.  Select the buffer properly for that.  */
   if (!update_mode_line)
     {