Don't copy memory to itself (valgrind complains).

Rev: src/modules/Image/layer_channel.h:1.10

src/modules/Image/layer_channel.h

@@ -2,7 +2,7 @@
 || This file is part of Pike. For copyright information see COPYRIGHT.
 || Pike is distributed under GPL, LGPL and MPL. See the file COPYING
 || for more information.
-|| $Id: layer_channel.h,v 1.9 2008/01/15 21:51:07 grubba Exp $
+|| $Id: layer_channel.h,v 1.10 2008/07/11 13:11:39 mast Exp $
 */
 
 /* template for operator layer row function */
@@ -11,11 +11,13 @@ static void LM_FUNC(rgb_group *s,rgb_group *l,rgb_group *d,
 		    rgb_group *sa,rgb_group *la,rgb_group *da,
 		    int len,double alpha)
 {
+  if (da != sa)
     MEMCPY(da,sa,sizeof(rgb_group)*len); /* always copy alpha channel */
 #define da da da /* protect */
    if (alpha==0.0)
    {
 #ifdef LAYER_DUAL
+     if (d != s)
        MEMCPY(d,s,sizeof(rgb_group)*len);
 #endif
       return;