updated for version 7.0109
diff --git a/src/os_riscos.c b/src/os_riscos.c
index 2894950..39a03cc 100644
--- a/src/os_riscos.c
+++ b/src/os_riscos.c
@@ -523,7 +523,7 @@
     if (xswi(OS_ReadVarVal, "Machine$Name", s, len, 0, 3) & v_flag)
     {
 	/* Variable does not exist (normal operation) */
-	STRNCPY(s, "(unknown)", len);
+	vim_strncpy(s, "(unknown)", len - 1);
     }
 }