(redisplay_internal, mark_window_display_accurate)

(redisplay_window): Test and update last_overlay_modified field
along with last_modified.

(overlay_unchanged_modified): New variable.
(redisplay_internal): Set overlay_unchanged_modified.

(redisplay_region): Renamed and moved to buffer.c.

1 files changed, 21 insertions, 75 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index 532d548b2dd..ab25dc67ebd 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -211,10 +211,14 @@ int beg_unchanged;
 int end_unchanged;
 
 /* MODIFF as of last redisplay that finished;
-   if it matches MODIFF, beg_unchanged and end_unchanged
+   if it matches MODIFF, and overlay_unchanged_modified
+   matches OVERLAY_MODIFF, that means beg_unchanged and end_unchanged
    contain no useful information */
 int unchanged_modified;
 
+/* OVERLAY_MODIFF as of last redisplay that finished.  */
+int overlay_unchanged_modified;
+
 /* Nonzero if window sizes or contents have changed
    since last redisplay that finished */
 int windows_or_buffers_changed;
@@ -897,7 +901,8 @@ redisplay_internal (preserve_echo_area)
       /* This alternative quickly identifies a common case
          where no change is needed.  */
       && !(PT == XFASTINT (w->last_point)
-           && XFASTINT (w->last_modified) >= MODIFF)
+           && XFASTINT (w->last_modified) >= MODIFF
+           && XFASTINT (w->last_overlay_modified) >= OVERLAY_MODIFF)
       && XFASTINT (w->column_number_displayed) != current_column ())
     w->update_mode_line = Qt; 
 
@@ -944,7 +949,8 @@ redisplay_internal (preserve_echo_area)
       && PT <= Z - tlendpos
       /* All text outside that line, including its final newline,
          must be unchanged */
-      && (XFASTINT (w->last_modified) >= MODIFF
+      && ((XFASTINT (w->last_modified) >= MODIFF
+           && (XFASTINT (w->last_overlay_modified) >= OVERLAY_MODIFF))
           || (beg_unchanged >= tlbufpos - 1
               && GPT >= tlbufpos
               /* If selective display, can't optimize
@@ -963,6 +969,7 @@ redisplay_internal (preserve_echo_area)
         /* Former continuation line has disappeared by becoming empty */
         goto cancel;
       else if (XFASTINT (w->last_modified) < MODIFF
+               || XFASTINT (w->last_overlay_modified) < OVERLAY_MODIFF
                || MINI_WINDOW_P (w))
         {
           cursor_vpos = -1;
@@ -1188,6 +1195,7 @@ update:
 
       blank_end_of_window = 0;
       unchanged_modified = BUF_MODIFF (b);
+      overlay_unchanged_modified = BUF_OVERLAY_MODIFF (b);
       beg_unchanged = BUF_GPT (b) - BUF_BEG (b);
       end_unchanged = BUF_Z (b) - BUF_GPT (b);
 
@@ -1202,6 +1210,7 @@ update:
           b->clip_changed = 0;
           w->update_mode_line = Qnil;
           XSETFASTINT (w->last_modified, BUF_MODIFF (b));
+          XSETFASTINT (w->last_overlay_modified, BUF_OVERLAY_MODIFF (b));
           w->last_had_star
             = (BUF_MODIFF (XBUFFER (w->buffer)) > BUF_SAVE_MODIFF (XBUFFER (w->buffer))
                ? Qt : Qnil);
@@ -1273,6 +1282,8 @@ mark_window_display_accurate (window, flag)
         {
           XSETFASTINT (w->last_modified,
                        !flag ? 0 : BUF_MODIFF (XBUFFER (w->buffer)));
+          XSETFASTINT (w->last_overlay_modified,
+                       !flag ? 0 : BUF_OVERLAY_MODIFF (XBUFFER (w->buffer)));
           w->last_had_star
             = (BUF_MODIFF (XBUFFER (w->buffer)) > BUF_SAVE_MODIFF (XBUFFER (w->buffer))
                ? Qt : Qnil);
@@ -1488,7 +1499,8 @@ redisplay_window (window, just_this_one, preserve_echo_area)
       /* This alternative quickly identifies a common case
          where no change is needed.  */
       && !(PT == XFASTINT (w->last_point)
-           && XFASTINT (w->last_modified) >= MODIFF)
+           && XFASTINT (w->last_modified) >= MODIFF
+           && XFASTINT (w->last_overlay_modified) >= OVERLAY_MODIFF)
       && XFASTINT (w->column_number_displayed) != current_column ())
     update_mode_line = 1; 
 
@@ -1584,6 +1596,7 @@ redisplay_window (window, just_this_one, preserve_echo_area)
             }
         }
       XSETFASTINT (w->last_modified, 0);
+      XSETFASTINT (w->last_overlay_modified, 0);
       if (startp < BEGV) startp = BEGV;
       if (startp > ZV)   startp = ZV;
       try_window (window, startp);
@@ -1633,6 +1646,7 @@ redisplay_window (window, just_this_one, preserve_echo_area)
      in redisplay handles the same cases.  */
 
   if (XFASTINT (w->last_modified) >= MODIFF
+      && XFASTINT (w->last_overlay_modified) >= OVERLAY_MODIFF
       && PT >= startp && !current_buffer->clip_changed
       && (just_this_one || XFASTINT (w->width) == FRAME_WIDTH (f))
       /* If force-mode-line-update was called, really redisplay;
@@ -1720,7 +1734,8 @@ redisplay_window (window, just_this_one, preserve_echo_area)
                || preserve_echo_area
 #endif
                || startp == BEGV
-               || (XFASTINT (w->last_modified) >= MODIFF)))
+               || (XFASTINT (w->last_modified) >= MODIFF
+                   && XFASTINT (w->last_overlay_modified) >= OVERLAY_MODIFF)))
     {
       /* Try to redisplay starting at same place as before */
       /* If point has not moved off frame, accept the results */
@@ -1738,6 +1753,7 @@ redisplay_window (window, just_this_one, preserve_echo_area)
     }
 
   XSETFASTINT (w->last_modified, 0);
+  XSETFASTINT (w->last_overlay_modified, 0);
   /* Redisplay the mode line.  Select the buffer properly for that.  */
   if (!update_mode_line)
     {
@@ -2356,76 +2372,6 @@ try_window_id (window)
   return 1;
 }
 
-/* Mark a section of BUF as modified, but only for the sake of redisplay.
-   This is useful for recording changes to overlays.
-
-   We increment the buffer's modification timestamp and set the
-   redisplay caches (windows_or_buffers_changed, beg_unchanged, etc)
-   as if the region of text between START and END had been modified;
-   the redisplay code will check this against the windows' timestamps,
-   and redraw the appropriate area of the buffer.
-
-   However, if the buffer is unmodified, we bump the last-save
-   timestamp as well, so that incrementing the timestamp doesn't fool
-   Emacs into thinking that the buffer's text has been modified. 
-
-   Tweaking the timestamps shouldn't hurt the first-modification
-   timestamps recorded in the undo records; those values aren't
-   written until just before a real text modification is made, so they
-   will never catch the timestamp value just before this function gets
-   called.  */
-
-void
-redisplay_region (buf, start, end)
-     struct buffer *buf;
-     int start, end;
-{
-  if (start == end)
-    return;
-
-  if (start > end)
-    {
-      int temp = start;
-      start = end; end = temp;
-    }
-
-  /* If this is a buffer not in the selected window,
-     we must do other windows.  */
-  if (buf != XBUFFER (XWINDOW (selected_window)->buffer))
-    windows_or_buffers_changed = 1;
-  /* If it's not current, we can't use beg_unchanged, end_unchanged for it.  */
-  else if (buf != current_buffer)
-    windows_or_buffers_changed = 1;
-  /* If multiple windows show this buffer, we must do other windows.  */
-  else if (buffer_shared > 1)
-    windows_or_buffers_changed = 1;
-  else
-    {
-      if (unchanged_modified == MODIFF)
-        {
-          beg_unchanged = start - BEG;
-          end_unchanged = Z - end;
-        }
-      else
-        {
-          if (Z - end < end_unchanged)
-            end_unchanged = Z - end;
-          if (start - BEG < beg_unchanged)
-            beg_unchanged = start - BEG;
-        }
-    }
-
-  /* Increment the buffer's time stamp, but also increment the save
-     and autosave timestamps, so as not to screw up that timekeeping.  */
-  if (BUF_MODIFF (buf) == BUF_SAVE_MODIFF (buf))
-    BUF_SAVE_MODIFF (buf)++;
-  if (BUF_MODIFF (buf) == buf->auto_save_modified)
-    buf->auto_save_modified++;
-
-  BUF_MODIFF (buf) ++;
-}
-
-
 /* Copy LEN glyphs starting address FROM to the rope TO.
    But don't actually copy the parts that would come in before S.
    Value is TO, advanced past the copied data.