--- mlterm-2.9.2/xwindow/x_screen.c.orig	2005-03-02 23:13:46.000000000 +0900
+++ mlterm-2.9.2/xwindow/x_screen.c	2006-12-17 01:12:45.000000000 +0900
@@ -1494,6 +1494,8 @@
 			end_row = swp ;
 		}
 
+		ml_term_set_modified_lines_in_screen( screen->term, beg_row, end_row );
+
 	#ifdef  __DEBUG
 		kik_debug_printf( KIK_DEBUG_TAG " exposed [row] from %d to %d [x] from %d to %d\n" ,
 			beg_row , end_row , x , x + width) ;
@@ -1504,14 +1506,32 @@
 		beg_row = convert_y_to_row( screen , NULL , y) ;
 		end_row = convert_y_to_row( screen , NULL , y + height) ;
 
+#ifdef OPTIMIZE_REDRAWING
+		ml_screen_logical( screen->term->screen );
+
+		int row;
+		for( row = beg_row; row <= end_row; ++row )
+		{
+			ml_line_t* line = ml_screen_get_line_in_screen( screen->term->screen, row );
+			if( line != NULL )
+			{
+				uint beg_col = convert_x_to_char_index( screen, line, NULL, x );
+				uint end_col = convert_x_to_char_index( screen, line, NULL, x + width );
+				ml_line_set_modified( line, beg_col, end_col );
+			}
+		}
+
+		ml_screen_visual( screen->term->screen );
+#else
+		ml_term_set_modified_lines_in_screen( screen->term, beg_row, end_row );
+#endif
+
 	#ifdef  __DEBUG
 		kik_debug_printf( KIK_DEBUG_TAG " exposed [row] from %d to %d [y] from %d to %d\n" ,
 			beg_row , end_row , y , y + height) ;
 	#endif
 	}
 
-	ml_term_set_modified_lines_in_screen( screen->term , beg_row , end_row) ;
-
 	redraw_screen( screen) ;
 	highlight_cursor( screen) ;
 }