Tests de borne moins severes dans contains

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@2317 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

stdlib/string.ml

@@ -144,7 +144,7 @@ let rec index_rec s lim i c =
 let index s c = index_rec s (length s) 0 c;;
 
 let index_from s i c =
-  if i < 0 || i >= length s then invalid_arg "String.index_from" else
+  if i < 0 || i > length s then invalid_arg "String.index_from" else
   index_rec s (length s) i c;;
 
 let rec rindex_rec s i c =
@@ -158,11 +158,11 @@ let rindex_from s i c =
   rindex_rec s i c;;
 
 let contains_from s i c =
-  if i < 0 || i >= length s then invalid_arg "String.contains_from" else
+  if i < 0 || i > length s then invalid_arg "String.contains_from" else
   try ignore(index_rec s (length s) i c); true with Not_found -> false;;
 
 let rcontains_from s i c =
   if i < 0 || i >= length s then invalid_arg "String.rcontains_from" else
   try ignore(rindex_rec s i c); true with Not_found -> false;;
 
-let contains s c = s <> "" && contains_from s 0 c;;
+let contains s c = contains_from s 0 c;;