(redisplay_internal): Clear garbaged frames after

resizing mini-window.
(unwind_with_echo_area_buffer): Use
set_buffer_internal_1 instead of set_buffer_internal.
(with_echo_area_buffer): Ditto.
(Vresize_mini_config): New.
(resize_mini_window): Use it to save restore original window
configuration
(syms_of_xdisp): Initialize it.
(reconsider_clip_changes): New.
(redisplay_internal, redisplay_window): Call it.
(mark_window_display_accurate, redisplay_internal): Set current
matrix' buffer, begv, zv.

1 files changed, 93 insertions, 64 deletions

diff --git a/src/xdisp.c b/src/xdisp.c
index a2e8a4b1b67..45cbe13f977 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -427,28 +427,6 @@ int message_enable_multibyte;
 
 int update_mode_lines;
 
-/* Smallest number of characters before the gap at any time since last
-   redisplay that finished.  Valid for current buffer when
-   try_window_id can be called.  */
-
-int beg_unchanged;
-
-/* Smallest number of characters after the gap at any time since last
-   redisplay that finished.  Valid for current buffer when
-   try_window_id can be called.  */
-
-int end_unchanged;
-
-/* MODIFF as of last redisplay that finished; 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 */
 
@@ -495,10 +473,16 @@ static int display_last_displayed_message_p;
 
 int message_buf_print;
 
-/* Maximum height for resizing mini-windows.  */
+/* Maximum height for resizing mini-windows.  Either a float
+   specifying a fraction of the available height, or an integer
+   specifying a number of lines.  */
 
 static Lisp_Object Vmax_mini_window_height;
 
+/* Window configuration saved in resize_mini_window.  */
+
+static Lisp_Object Vresize_mini_config;
+
 /* A scratch glyph row with contents used for generating truncation
    glyphs.  Also used in direct_output_for_insert.  */
 
@@ -5221,7 +5205,7 @@ with_echo_area_buffer (w, which, fn, a1, a2, a3, a4, a5)
      Fset_window_buffer.  We must also change w->pointm, though,
      because otherwise an assertions in unshow_buffer fails, and Emacs
      aborts.  */
-  set_buffer_internal (XBUFFER (buffer));
+  set_buffer_internal_1 (XBUFFER (buffer));
   if (w)
     {
       w->buffer = buffer;
@@ -5263,13 +5247,11 @@ with_echo_area_buffer_unwind_data (w)
   Vwith_echo_area_save_vector = Qnil;
   
   if (NILP (vector))
-    vector = Fmake_vector (make_number (9), Qnil);
+    vector = Fmake_vector (make_number (7), Qnil);
   
   XSETBUFFER (XVECTOR (vector)->contents[i], current_buffer); ++i;
   XVECTOR (vector)->contents[i++] = Vdeactivate_mark;
   XVECTOR (vector)->contents[i++] = make_number (windows_or_buffers_changed);
-  XVECTOR (vector)->contents[i++] = make_number (beg_unchanged);
-  XVECTOR (vector)->contents[i++] = make_number (end_unchanged);
   
   if (w)
     {
@@ -5301,11 +5283,9 @@ unwind_with_echo_area_buffer (vector)
 {
   int i = 0;
   
-  set_buffer_internal (XBUFFER (XVECTOR (vector)->contents[i])); ++i;
+  set_buffer_internal_1 (XBUFFER (XVECTOR (vector)->contents[i])); ++i;
   Vdeactivate_mark = XVECTOR (vector)->contents[i]; ++i;
   windows_or_buffers_changed = XFASTINT (XVECTOR (vector)->contents[i]); ++i;
-  beg_unchanged = XFASTINT (XVECTOR (vector)->contents[i]); ++i;
-  end_unchanged = XFASTINT (XVECTOR (vector)->contents[i]); ++i;
 
   if (WINDOWP (XVECTOR (vector)->contents[i]))
     {
@@ -5447,7 +5427,7 @@ resize_mini_window (w)
       int height, max_height;
       int unit = CANON_Y_UNIT (f);
       struct text_pos start;
-      
+
       init_iterator (&it, w, BEGV, BEGV_BYTE, NULL, DEFAULT_FACE_ID);
 
       /* Compute the max. number of lines specified by the user.  */
@@ -5478,9 +5458,14 @@ resize_mini_window (w)
       SET_MARKER_FROM_TEXT_POS (w->start, start);
       
       /* Change window's height, if necessary.  */
-      if (height != XFASTINT (w->height))
+      if (height > XFASTINT (w->height)
+          || (height < XFASTINT (w->height)
+              && NILP (Vresize_mini_config)))
         {
           Lisp_Object old_selected_window;
+
+          if (NILP (Vresize_mini_config))
+            Vresize_mini_config = Fcurrent_window_configuration (Qnil);
           
           old_selected_window = selected_window;
           XSETWINDOW (selected_window, w);
@@ -5488,6 +5473,13 @@ resize_mini_window (w)
           selected_window = old_selected_window;
           window_height_changed_p = 1;
         }
+      else if (height < XFASTINT (w->height)
+               && !NILP (Vresize_mini_config))
+        {
+          Fset_window_configuration (Vresize_mini_config);
+          Vresize_mini_config = Qnil;
+          window_height_changed_p = 1;
+        }
     }
 
   return window_height_changed_p;
@@ -6729,11 +6721,6 @@ hscroll_windows (window)
 
 #if GLYPH_DEBUG
 
-/* Values of beg_unchanged and end_unchanged as of last call to
-   try_window_id.  */
-
-int debug_beg_unchanged, debug_end_unchanged;
-
 /* First and last unchanged row for try_window_id.  */
 
 int debug_first_unchanged_at_end_vpos;
@@ -6830,8 +6817,8 @@ text_outside_line_unchanged_p (w, start, end)
 
       /* Changes start in front of the line, or end after it?  */
       if (unchanged_p
-          && (beg_unchanged < start - 1
-              || end_unchanged < end))
+          && (BEG_UNCHANGED < start - 1
+              || END_UNCHANGED < end))
         unchanged_p = 0;
       
       /* If selective display, can't optimize if changes start at the
@@ -6839,7 +6826,7 @@ text_outside_line_unchanged_p (w, start, end)
       if (unchanged_p
           && INTEGERP (current_buffer->selective_display)
           && XINT (current_buffer->selective_display) > 0
-          && (beg_unchanged < start || GPT <= start))
+          && (BEG_UNCHANGED < start || GPT <= start))
         unchanged_p = 0;
     }
 
@@ -6861,6 +6848,25 @@ redisplay ()
 }
 
 
+/* Reconsider the setting of B->clip_changed which is displayed
+   in window W.  */
+
+static INLINE void
+reconsider_clip_changes (w, b)
+     struct window *w;
+     struct buffer *b;
+{
+  if (b->prevent_redisplay_optimizations_p)
+    b->clip_changed = 1;
+  else if (b->clip_changed
+           && !NILP (w->window_end_valid)
+           && w->current_matrix->buffer == b
+           && w->current_matrix->zv == BUF_ZV (b)
+           && w->current_matrix->begv == BUF_BEGV (b))
+    b->clip_changed = 0;
+}
+
+
 /* If PRESERVE_ECHO_AREA is nonzero, it means this redisplay is not in
    response to any user action; therefore, we should preserve the echo
    area.  (Actually, our caller does that job.)  Perhaps in the future
@@ -6920,6 +6926,8 @@ redisplay_internal (preserve_echo_area)
   
  retry:
 
+  reconsider_clip_changes (w, current_buffer);
+
   /* If new fonts have been loaded that make a glyph matrix adjustment
      necessary, do it.  */
   if (fonts_changed_p)
@@ -6971,8 +6979,6 @@ redisplay_internal (preserve_echo_area)
   /* Build menubar and toolbar items.  */
   prepare_menu_bars ();
 
- retry_1:
-
   if (windows_or_buffers_changed)
     update_mode_lines++;
 
@@ -7024,6 +7030,12 @@ redisplay_internal (preserve_echo_area)
           consider_all_windows_p = 1;
           ++update_mode_lines;
           ++windows_or_buffers_changed;
+          
+          /* If window configuration was changed, frames may have been
+             marked garbaged.  Clear them or we will experience
+             surprises wrt scrolling.  */
+          if (frame_garbaged)
+            clear_garbaged_frames ();
         }
     }
   else if (w == XWINDOW (minibuf_window)
@@ -7038,6 +7050,12 @@ redisplay_internal (preserve_echo_area)
       consider_all_windows_p = 1;
       ++windows_or_buffers_changed;
       ++update_mode_lines;
+      
+      /* If window configuration was changed, frames may have been
+         marked garbaged.  Clear them or we will experience
+         surprises wrt scrolling.  */
+      if (frame_garbaged)
+        clear_garbaged_frames ();
     }
   
 
@@ -7417,10 +7435,10 @@ update:
     {
       register struct buffer *b = XBUFFER (w->buffer);
 
-      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);
+      BUF_UNCHANGED_MODIFIED (b) = BUF_MODIFF (b);
+      BUF_OVERLAY_UNCHANGED_MODIFIED (b) = BUF_OVERLAY_MODIFF (b);
+      BUF_BEG_UNCHANGED (b) = BUF_GPT (b) - BUF_BEG (b);
+      BUF_END_UNCHANGED (b) = BUF_Z (b) - BUF_GPT (b);
 
       if (consider_all_windows_p)
         mark_window_display_accurate (FRAME_ROOT_WINDOW (selected_frame), 1);
@@ -7431,6 +7449,7 @@ update:
           w->last_cursor_off_p = w->cursor_off_p;
 
           b->clip_changed = 0;
+          b->prevent_redisplay_optimizations_p = 0;
           w->update_mode_line = Qnil;
           XSETFASTINT (w->last_modified, BUF_MODIFF (b));
           XSETFASTINT (w->last_overlay_modified, BUF_OVERLAY_MODIFF (b));
@@ -7452,6 +7471,10 @@ update:
           last_arrow_string = Voverlay_arrow_string;
           if (frame_up_to_date_hook != 0)
             (*frame_up_to_date_hook) (selected_frame);
+
+          w->current_matrix->buffer = b;
+          w->current_matrix->begv = BUF_BEGV (b);
+          w->current_matrix->zv = BUF_ZV (b);
         }
       
       update_mode_lines = 0;
@@ -7589,6 +7612,10 @@ mark_window_display_accurate (window, accurate_p)
           if (accurate_p)
             {
               b->clip_changed = 0;
+              b->prevent_redisplay_optimizations_p = 0;
+              w->current_matrix->buffer = b;
+              w->current_matrix->begv = BUF_BEGV (b);
+              w->current_matrix->zv = BUF_ZV (b);
               w->last_cursor = w->cursor;
               w->last_cursor_off_p = w->cursor_off_p;
               if (w == XWINDOW (selected_window))
@@ -8039,7 +8066,7 @@ try_scrolling (window, just_this_one_p, scroll_conservatively,
       /* Maybe forget recorded base line for line number display.  */
       if (!just_this_one_p 
           || current_buffer->clip_changed
-          || beg_unchanged < CHARPOS (startp))
+          || BEG_UNCHANGED < CHARPOS (startp))
         w->base_line_number = Qnil;
       
       /* If cursor ends up on a partially visible line, shift display
@@ -8150,7 +8177,9 @@ redisplay_window (window, just_this_one_p)
 #endif
 
   specbind (Qinhibit_point_motion_hooks, Qt);
-  
+
+  reconsider_clip_changes (w, buffer);
+    
   /* Has the mode line to be updated?  */ 
   update_mode_line = (!NILP (w->update_mode_line)
                       || update_mode_lines
@@ -8573,7 +8602,8 @@ redisplay_window (window, just_this_one_p)
     }
   
   /* Try scrolling with try_window_id.  */
-  else if (!windows_or_buffers_changed
+  else if (/* Windows and buffers haven't changed.  */
+           !windows_or_buffers_changed
            /* Window must be either use window-based redisplay or
               be full width.  */
            && (FRAME_WINDOW_P (f)
@@ -8647,7 +8677,7 @@ redisplay_window (window, just_this_one_p)
         {
           if (!just_this_one_p 
               || current_buffer->clip_changed
-              || beg_unchanged < CHARPOS (startp))
+              || BEG_UNCHANGED < CHARPOS (startp))
             /* Forget any recorded base line for line number display.  */
             w->base_line_number = Qnil;
           
@@ -9428,7 +9458,7 @@ static struct glyph_row *
 get_last_unchanged_at_beg_row (w)
      struct window *w;
 {
-  int first_changed_pos = BEG + beg_unchanged;
+  int first_changed_pos = BEG + BEG_UNCHANGED;
   struct glyph_row *row;
   struct glyph_row *row_found = NULL;
   int yb = window_text_bottom_y (w);
@@ -9488,7 +9518,7 @@ get_first_unchanged_at_end_row (w, delta, delta_bytes)
      end is in the range of changed text.  If so, there is no
      unchanged row at the end of W's current matrix.  */
   xassert (!NILP (w->window_end_valid));
-  if (XFASTINT (w->window_end_pos) >= end_unchanged)
+  if (XFASTINT (w->window_end_pos) >= END_UNCHANGED)
     return NULL;
 
   /* Set row to the last row in W's current matrix displaying text.  */
@@ -9517,7 +9547,7 @@ get_first_unchanged_at_end_row (w, delta, delta_bytes)
          subtracting end_unchanged we get the index of the last
          unchanged character, and we have to add BEG to get its buffer
          position.  */
-      last_unchanged_pos = Z - end_unchanged + BEG;
+      last_unchanged_pos = Z - END_UNCHANGED + BEG;
       last_unchanged_pos_old = last_unchanged_pos - *delta;
       
       /* Search backward from ROW for a row displaying a line that
@@ -9644,10 +9674,10 @@ try_window_id (w)
      set end_unchanged to 0 in that case.  */
   if (MODIFF > SAVE_MODIFF)
     {
-      if (GPT - BEG < beg_unchanged)
-        beg_unchanged = GPT - BEG;
-      if (Z - GPT < end_unchanged)
-        end_unchanged = Z - GPT;
+      if (GPT - BEG < BEG_UNCHANGED)
+        BEG_UNCHANGED = GPT - BEG;
+      if (Z - GPT < END_UNCHANGED)
+        END_UNCHANGED = Z - GPT;
     }
   
   /* If window starts after a line end, and the last change is in
@@ -9655,7 +9685,7 @@ try_window_id (w)
      This case happens with stealth-fontification.  */
   row = MATRIX_ROW (w->current_matrix, XFASTINT (w->window_end_vpos));
   if (CHARPOS (start) > BEGV
-      && Z - end_unchanged < CHARPOS (start) - 1
+      && Z - END_UNCHANGED < CHARPOS (start) - 1
       && FETCH_BYTE (BYTEPOS (start) - 1) == '\n'
       && PT < MATRIX_ROW_END_CHARPOS (row))
     {
@@ -9670,7 +9700,7 @@ try_window_id (w)
 
   /* Return quickly if changes are all below what is displayed in the
      window, and if PT is in the window.  */
-  if (beg_unchanged > MATRIX_ROW_END_CHARPOS (row)
+  if (BEG_UNCHANGED > MATRIX_ROW_END_CHARPOS (row)
       && PT < MATRIX_ROW_END_CHARPOS (row))
     {
       /* We have to update window end positions because the buffer's
@@ -9690,10 +9720,6 @@ try_window_id (w)
   if (!TEXT_POS_EQUAL_P (start, row->start.pos))
     return 0;
 
-  /* Remember beg_unchanged and end_unchanged for debugging purposes.  */
-  IF_DEBUG (debug_beg_unchanged = beg_unchanged;
-            debug_end_unchanged = end_unchanged);
-
   /* Compute the position at which we have to start displaying new
      lines.  Some of the lines at the top of the window might be
      reusable because they are not displaying changed text.  Find the
@@ -9769,7 +9795,7 @@ try_window_id (w)
                       + delta);
           first_unchanged_at_end_vpos
             = MATRIX_ROW_VPOS (first_unchanged_at_end_row, current_matrix);
-          xassert (stop_pos >= Z - end_unchanged);
+          xassert (stop_pos >= Z - END_UNCHANGED);
         }
     }
   else if (last_unchanged_at_beg_row == NULL)
@@ -12408,6 +12434,9 @@ invisible_ellipsis_p (propval, list)
 void
 syms_of_xdisp ()
 {
+  Vresize_mini_config = Qnil;
+  staticpro (&Vresize_mini_config);
+
   Vwith_echo_area_save_vector = Qnil;
   staticpro (&Vwith_echo_area_save_vector);