Correction bug #1477 sur ordre des variables partagées par les or-patterns.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svn/coq/trunk@9764 85f007b7-540e-0410-9357-904b9bb8a0f7

4 files changed, 22 insertions, 3 deletions

diff --git a/interp/constrintern.ml b/interp/constrintern.ml
index f067eda6b5..77e6ba42cf 100644
--- a/interp/constrintern.ml
+++ b/interp/constrintern.ml
@@ -384,7 +384,7 @@ let check_number_of_pattern loc n l =
   if n<>p then raise (InternalisationError (loc,BadPatternsNumber (n,p)))
 
 let check_or_pat_variables loc ids idsl =
-  if List.exists ((<>) ids) idsl then
+  if List.exists (fun ids' -> not (list_eq_set ids ids')) idsl then
     user_err_loc (loc, "", str 
     "The components of this disjunctive pattern must bind the same variables")
 
diff --git a/lib/util.ml b/lib/util.ml
index 66485d5a36..ee373120e2 100644
--- a/lib/util.ml
+++ b/lib/util.ml
@@ -123,8 +123,6 @@ module Stringmap = Map.Make(struct type t = string let compare = compare end)
 
 (* Lists *)
 
-let list_add_set x l = if List.mem x l then l else x::l
-
 let list_intersect l1 l2 = 
   List.filter (fun x -> List.mem x l2) l1
 
@@ -267,6 +265,14 @@ let rec list_remove_first a = function
   | b::l -> b::list_remove_first a l
   | [] -> raise Not_found
 
+let list_add_set x l = if List.mem x l then l else x::l
+
+let list_eq_set l1 l2 =
+  let rec aux l1 = function
+  | [] -> l1 = []
+  | a::l2 -> aux (list_remove_first a l1) l2 in
+  try aux l1 l2 with Not_found -> false
+
 let list_for_all2eq f l1 l2 = try List.for_all2 f l1 l2 with Failure _ -> false
 
 let list_map_i f = 
diff --git a/lib/util.mli b/lib/util.mli
index f38f36740c..afa11d31dc 100644
--- a/lib/util.mli
+++ b/lib/util.mli
@@ -78,6 +78,7 @@ module Stringmap : Map.S with type key = string
 (*s Lists. *)
 
 val list_add_set : 'a -> 'a list -> 'a list
+val list_eq_set : 'a list -> 'a list -> bool
 val list_intersect : 'a list -> 'a list -> 'a list
 val list_union : 'a list -> 'a list -> 'a list
 val list_unionq : 'a list -> 'a list -> 'a list
diff --git a/test-suite/success/Case18.v b/test-suite/success/Case18.v
index 91c80e8891..be9ca8d41b 100644
--- a/test-suite/success/Case18.v
+++ b/test-suite/success/Case18.v
@@ -12,3 +12,15 @@ Fixpoint max (n m:nat) {struct m} : nat :=
   | S n', S m' => S (max n' m')
   | 0, p | p, 0 => p
   end.
+
+(* Check bug #1477 *)
+
+Inductive I : Set :=
+  | A : nat -> nat -> I
+  | B : nat -> nat -> I.
+
+Definition foo (x:I) : nat :=
+  match x with
+    | A a b | B b a => S b
+  end.
+