Bug fixed: %n was badly failing (with Failure "nth") when n was

not a valid constructor. Now fail is raised (to be captured by
try, etc.)

diff --git a/matita/components/ng_tactics/nTactics.ml b/matita/components/ng_tactics/nTactics.ml
index 044f496f15051c0b8c86714736ed42c23fd63380..6870dab573a258ec0c0e91d06b6dfdca72fdfe5f 100644 (file)
--- a/matita/components/ng_tactics/nTactics.ml
+++ b/matita/components/ng_tactics/nTactics.ml
@@ -624,9 +624,9 @@ let case1_tac name =
 ;;
 
 let constructor_tac ?(num=1) ~args = distribute_tac (fun status goal ->
-  if num < 1 then fail (lazy "constructor numbers begin with 1");
   let gty = get_goalty status goal in
-  let status, (r,_,_,_) = analyse_indty status gty in
+  let status, (r,consno,_,_) = analyse_indty status gty in
+  if num < 1 || num > consno then fail (lazy "Non existant constructor");
   let ref = NReference.mk_constructor num r in
   let t = 
     if args = [] then Ast.NRef ref else