fix bug in op-describe for ::pcat case, tests now pass

Author: dnolen

src/main/cljs/cljs/spec.cljs

@@ -953,7 +953,7 @@
         ::amp (list* 'clojure.spec/& (op-describe p1) forms)
         ::pcat (if rep+
                  (list `+ rep+)
-                 (cons `cat (mapcat vector (c/or (seq ks) (repeat :_)) (c/or (seq forms) (repeat nil)))))
+                 (cons `cat (mapcat vector (c/or (seq ks) (repeat :_)) forms)))
         ::alt (if maybe
                 (list `? maybe)
                 (cons `alt (mapcat vector ks forms)))

src/test/cljs/cljs/spec_test.cljs

@@ -134,7 +134,7 @@
       c ["s" :k 5] ::s/invalid '[{:reason "Extra input", :pred (cat :a string? :b keyword?), :val (5)}]
 
       (s/cat) nil {} nil
-      ;(s/cat) [5] ::s/invalid '[{:reason "Extra input", :pred (cat), :val (5), :in [0]}]
+      (s/cat) [5] ::s/invalid '[{:reason "Extra input", :pred (cat), :val (5), :in [0]}]
 
       either nil ::s/invalid '[{:reason "Insufficient input", :pred (alt :a string? :b keyword?), :val () :via []}]
       either [] ::s/invalid '[{:reason "Insufficient input", :pred (alt :a string? :b keyword?), :val () :via []}]