(redisplay_mode_lines): New function.

(display_mode_lines): Return number of mode lines displayed.
(echo_area_display): Use redisplay_mode_lines to draw garbaged
mode lines.  Don't temporarily bind redisplay-dont-pause to t.

2 files changed, 130 insertions, 33 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 09108b858f6..9f7bc8fc412 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,10 @@
 2000-09-02  Gerd Moellmann  <gerd@gnu.org>
 
+        * xdisp.c (redisplay_mode_lines): New function.
+        (display_mode_lines): Return number of mode lines displayed.
+        (echo_area_display): Use redisplay_mode_lines to draw garbaged
+        mode lines.  Don't temporarily bind redisplay-dont-pause to t.
+
         * emacs.c, callint.c, doc.c, editfns.c: Remove includes of
         string.h and strings.h.
         (index) [HAVE_INDEX]: Add prototype.
diff --git a/src/xdisp.c b/src/xdisp.c
index e8805a314f2..351d710ea40 100644
--- a/src/xdisp.c
+++ b/src/xdisp.c
@@ -624,6 +624,7 @@ enum move_it_result
 
 /* Function prototypes.  */
 
+static int redisplay_mode_lines P_ ((Lisp_Object, int));
 static char *decode_mode_spec_coding P_ ((Lisp_Object, char *, int));
 static int invisible_text_between_p P_ ((struct it *, int, int));
 static int next_element_from_ellipsis P_ ((struct it *));
@@ -682,7 +683,7 @@ static void update_menu_bar P_ ((struct frame *, int));
 static int try_window_reusing_current_matrix P_ ((struct window *));
 static int try_window_id P_ ((struct window *));
 static int display_line P_ ((struct it *));
-static void display_mode_lines P_ ((struct window *));
+static int display_mode_lines P_ ((struct window *));
 static void display_mode_line P_ ((struct window *, enum face_id,
                                    Lisp_Object));
 static int display_mode_element P_ ((struct it *, int, int, int, Lisp_Object));
@@ -6290,26 +6291,30 @@ echo_area_display (update_frame_p)
       window_height_changed_p = display_echo_area (w);
       w->must_be_updated_p = 1;
 
+      /* Update the display, unless called from redisplay_internal. */
       if (update_frame_p)
         {
-          /* Not called from redisplay_internal. */
+          int n = 0;
 
-          if (!display_completed || window_height_changed_p)
+          /* If the display update has been interrupted by pending
+             input, update mode lines in the frame.  Due to the
+             pending input, it might have been that redisplay hasn't
+             been called, so that mode lines above the echo area are
+             garbaged.  This looks odd, so we prevent it here.  */
+          if (!display_completed)
+            n = redisplay_mode_lines (FRAME_ROOT_WINDOW (f), 0);
+            
+          if (window_height_changed_p)
             {
-              /* Must update other windows.  If current display is not
-                 up-to-date because the last redisplay was interrupted
-                 by pending input, esp. the mode-line above the echo
-                 area might display garbage which looks odd.  */
-              int count = specpdl_ptr - specpdl;
-              specbind (Qredisplay_dont_pause, Qt);
+              /* Must update other windows.  */
               windows_or_buffers_changed = 1;
               redisplay_internal (0);
-              unbind_to (count, Qnil);
             }
-          else if (FRAME_WINDOW_P (f))
+          else if (FRAME_WINDOW_P (f) && n == 0)
             {
               /* Window configuration is the same as before.
-                 Can do with a display update of the echo area.  */
+                 Can do with a display update of the echo area,
+                 unless we displayed some mode lines.  */
               update_single_window (w, 1);
               rif->flush_display (f);
             }
@@ -12026,23 +12031,106 @@ display_menu_bar (w)
                               Mode Line
  ***********************************************************************/
 
-/* Display the mode and/or top line of window W.  */
+/* Redisplay mode lines in the window tree whose root is WINDOW.  If
+   FORCE is non-zero, redisplay mode lines unconditionally.
+   Otherwise, redisplay only mode lines that are garbaged.  Value is
+   the number of windows whose mode lines were redisplayed.  */
 
-static void
+static int
+redisplay_mode_lines (window, force)
+     Lisp_Object window;
+     int force;
+{
+  int nwindows = 0;
+  
+  while (!NILP (window))
+    {
+      struct window *w = XWINDOW (window);
+      
+      if (WINDOWP (w->hchild))
+        nwindows += redisplay_mode_lines (w->hchild, force);
+      else if (WINDOWP (w->vchild))
+        nwindows += redisplay_mode_lines (w->vchild, force);
+      else if (force
+               || FRAME_GARBAGED_P (XFRAME (w->frame))
+               || !MATRIX_MODE_LINE_ROW (w->current_matrix)->enabled_p)
+        {
+          Lisp_Object old_selected_frame;
+          struct text_pos lpoint;
+          struct buffer *old = current_buffer;
+
+          /* Set the window's buffer for the mode line display.  */
+          SET_TEXT_POS (lpoint, PT, PT_BYTE);
+          set_buffer_internal_1 (XBUFFER (w->buffer));
+          
+          /* Point refers normally to the selected window.  For any
+             other window, set up appropriate value.  */
+          if (!EQ (window, selected_window))
+            {
+              struct text_pos pt;
+              
+              SET_TEXT_POS_FROM_MARKER (pt, w->pointm);
+              if (CHARPOS (pt) < BEGV)
+                TEMP_SET_PT_BOTH (BEGV, BEGV_BYTE);
+              else if (CHARPOS (pt) > (ZV - 1))
+                TEMP_SET_PT_BOTH (ZV, ZV_BYTE);
+              else
+                TEMP_SET_PT_BOTH (CHARPOS (pt), BYTEPOS (pt));
+            }
+
+          /* Temporarily set up the selected frame.  */
+          old_selected_frame = selected_frame;
+          selected_frame = w->frame;
+
+          /* Display mode lines.  */
+          clear_glyph_matrix (w->desired_matrix);
+          if (display_mode_lines (w))
+            {
+              ++nwindows;
+              w->must_be_updated_p = 1;
+            }
+
+          /* Restore old settings.  */
+          selected_frame = old_selected_frame;
+          set_buffer_internal_1 (old);
+          TEMP_SET_PT_BOTH (CHARPOS (lpoint), BYTEPOS (lpoint));
+        }
+
+      window = w->next;
+    }
+
+  return nwindows;
+}
+
+
+/* Display the mode and/or top line of window W.  Value is the number
+   of mode lines displayed.  */
+
+static int
 display_mode_lines (w)
      struct window *w;
 {
+  int n = 0;
+  
   /* These will be set while the mode line specs are processed.  */
   line_number_displayed = 0;
   w->column_number_displayed = Qnil;
 
   if (WINDOW_WANTS_MODELINE_P (w))
-    display_mode_line (w, MODE_LINE_FACE_ID,
-                       current_buffer->mode_line_format);
+    {
+      display_mode_line (w, MODE_LINE_FACE_ID,
+                         current_buffer->mode_line_format);
+      ++n;
+    }
   
   if (WINDOW_WANTS_HEADER_LINE_P (w))
-    display_mode_line (w, HEADER_LINE_FACE_ID,
-                       current_buffer->header_line_format);
+    {
+      display_mode_line (w, HEADER_LINE_FACE_ID,
+                         current_buffer->header_line_format);
+      ++n;
+    }
+
+  return n;
 }
 
 
@@ -13157,6 +13245,7 @@ invisible_p (propval, list)
      Lisp_Object list;
 {
   register Lisp_Object tail, proptail;
+  
   for (tail = list; CONSP (tail); tail = XCDR (tail))
     {
       register Lisp_Object tem;
@@ -13166,22 +13255,25 @@ invisible_p (propval, list)
       if (CONSP (tem) && EQ (propval, XCAR (tem)))
         return 1;
     }
+  
   if (CONSP (propval))
-    for (proptail = propval; CONSP (proptail);
-         proptail = XCDR (proptail))
-      {
-        Lisp_Object propelt;
-        propelt = XCAR (proptail);
-        for (tail = list; CONSP (tail); tail = XCDR (tail))
-          {
-            register Lisp_Object tem;
-            tem = XCAR (tail);
-            if (EQ (propelt, tem))
-              return 1;
-            if (CONSP (tem) && EQ (propelt, XCAR (tem)))
-              return 1;
-          }
-      }
+    {
+      for (proptail = propval; CONSP (proptail); proptail = XCDR (proptail))
+        {
+          Lisp_Object propelt;
+          propelt = XCAR (proptail);
+          for (tail = list; CONSP (tail); tail = XCDR (tail))
+            {
+              register Lisp_Object tem;
+              tem = XCAR (tail);
+              if (EQ (propelt, tem))
+                return 1;
+              if (CONSP (tem) && EQ (propelt, XCAR (tem)))
+                return 1;
+            }
+        }
+    }
+  
   return 0;
 }