Index: megatest.scm
==================================================================
--- megatest.scm
+++ megatest.scm
@@ -226,11 +226,11 @@
 ;; a,b,c % => a/%,b/%,c/%
 (define (tack-on-patt srcstr patt)
   (let ((strlst (string-split srcstr ",")))
     (string-intersperse 
      (map (lambda (str)
-	    (if (substring-index "/" str)
+	    (if (not (substring-index "/" str))
 		(conc str "/" patt)
 		str))
 	  strlst)
 	   ",")))