diff -up ksh-20120801/src/cmd/ksh93/sh/main.c.fixargs ksh-20120801/src/cmd/ksh93/sh/main.c
--- ksh-20120801/src/cmd/ksh93/sh/main.c.fixargs	2013-12-31 11:32:14.917874134 +0100
+++ ksh-20120801/src/cmd/ksh93/sh/main.c	2013-12-31 11:32:58.028847126 +0100
@@ -757,7 +757,7 @@ static void fixargs(char **argv, int mod
 		offset += size;
 		buff[offset++] = ' ';
 	}
-	buff[offset-1] = 0;
+	memset(&buff[offset - 1], 0, command_len - offset + 1);
 #   ifdef PSTAT
 	un.pst_command = stakptr(0);
 	pstat(PSTAT_SETCMD,un,0,0,0);