PR#5742: missing bound checks in Array.sub (picking r12891 from 4.00 branch)

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@12892 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

1 files changed, 8 insertions, 3 deletions

diff --git a/stdlib/array.ml b/stdlib/array.ml
index 37c663dc1..d17582a43 100644
--- a/stdlib/array.ml
+++ b/stdlib/array.ml
@@ -22,7 +22,7 @@ external unsafe_get: 'a array -> int -> 'a = "%array_unsafe_get"
 external unsafe_set: 'a array -> int -> 'a -> unit = "%array_unsafe_set"
 external make: int -> 'a -> 'a array = "caml_make_vect"
 external create: int -> 'a -> 'a array = "caml_make_vect"
-external sub : 'a array -> int -> int -> 'a array = "caml_array_sub"
+external unsafe_sub : 'a array -> int -> int -> 'a array = "caml_array_sub"
 external append_prim : 'a array -> 'a array -> 'a array = "caml_array_append"
 external concat : 'a array list -> 'a array = "caml_array_concat"
 external unsafe_blit : 'a array -> int -> 'a array -> int -> int -> unit = "caml_array_blit"
@@ -45,14 +45,19 @@ let make_matrix sx sy init =
 let create_matrix = make_matrix
 
 let copy a =
-  let l = length a in if l = 0 then [||] else sub a 0 l
+  let l = length a in if l = 0 then [||] else unsafe_sub a 0 l
 
 let append a1 a2 =
   let l1 = length a1 in
   if l1 = 0 then copy a2
-  else if length a2 = 0 then sub a1 0 l1
+  else if length a2 = 0 then unsafe_sub a1 0 l1
   else append_prim a1 a2
 
+let sub a ofs len =
+  if len < 0 || ofs > length a - len
+  then invalid_arg "Array.sub"
+  else unsafe_sub a ofs len
+
 let fill a ofs len v =
   if ofs < 0 || len < 0 || ofs > length a - len
   then invalid_arg "Array.fill"