--- a/usr/src/cmd/sed/main.c	Wed Dec 15 22:28:29 2010 -0800
+++ b/usr/src/cmd/sed/main.c	Thu Dec 16 09:43:44 2010 -0800
@@ -336,6 +336,8 @@
 		if (infile != NULL) {
 			(void) fclose(infile);
 			if (*oldfname != '\0') {
+				/* if there was a backup file, remove it */
+				(void) unlink(oldfname);
 				if (link(fname, oldfname) != 0) {
 					warn("link()");
 					(void) unlink(tmpfname);