Index: src/create.c
===================================================================
--- src/create.c
+++ src/create.c	2010-11-27 14:49:03.000000000 +0100
@@ -562,8 +562,9 @@
   GNAME_TO_CHARS (tmpname, header->header.gname);
   free (tmpname);
 
-  strcpy (header->buffer + offsetof (struct posix_header, magic),
-	  OLDGNU_MAGIC);
+  strncpy (header->header.magic, OLDGNU_MAGIC, sizeof(header->header.magic));
+   strncpy (header->header.version, OLDGNU_MAGIC+sizeof(header->header.magic),
+           sizeof(header->header.version));
   header->header.typeflag = type;
   finish_header (st, header, -1);
 
@@ -898,10 +899,14 @@
       break;
 
     case OLDGNU_FORMAT:
-    case GNU_FORMAT:   /*FIXME?*/
-      /* Overwrite header->header.magic and header.version in one blow.  */
-      strcpy (header->buffer + offsetof (struct posix_header, magic),
-	      OLDGNU_MAGIC);
+    case GNU_FORMAT:
+
+      /* OLDGNU_MAGIC is string with 7 chars + NULL */
+      strncpy (header->header.magic, OLDGNU_MAGIC,
+		      sizeof(header->header.magic));
+      strncpy (header->header.version,
+		      OLDGNU_MAGIC+sizeof(header->header.magic),
+		      sizeof(header->header.version));
       break;
 
     case POSIX_FORMAT: