--- rxvt-unicode/src/screen.C	2006/01/27 18:36:43	1.253
+++ rxvt-unicode/src/screen.C	2006/01/28 14:23:16	1.254
@@ -128,7 +128,7 @@
 
   l.touch ();
 
-  efs &= ~RS_baseattrMask;
+  efs &= ~RS_baseattrMask; // remove italic etc. fontstyles
   efs = SET_FONT (efs, FONTSET (efs)->find_font (' '));
 
   text_t *et = l.t + col;
@@ -642,7 +642,20 @@
 
       // erase newly scrolled-in lines
       for (int i = count; i--; )
-        scr_blank_screen_mem (ROW(nrow - 1 - i), rstyle);
+        {
+          line_t &l = ROW(nrow - 1 - i);
+
+          // optimize if already cleared, can be significant on slow machines
+          // could be rolled into scr_blank_screen_mem
+          if (l.r && l.l < ncol - 1 && !((l.r[l.l + 1] ^ rstyle) & RS_bgMask))
+            {
+              scr_blank_line (l, 0, l.l, rstyle);
+              l.l = 0;
+              l.f = 0;
+            }
+          else
+            scr_blank_screen_mem (l, rstyle);
+        }
 
       // now copy lines below the scroll region bottom to the
       // bottom of the screen again, so they look as if they