Merge pull request #80 from mirage/fix-adler32-ocaml

Add tests about adler32

src-ocaml/gin_adler32.ml

@@ -9,9 +9,13 @@ let _nmax = 5552
 let digest : type a. get:(a -> int -> char) -> a -> int -> int -> t -> t =
  fun ~get buf off len adler32 ->
   let a =
-    ref Optint.(to_unsigned_int Infix.((adler32 lsr 16) land of_int 0xFFFF))
+    ref
+      Optint.(
+        to_unsigned_int Infix.((adler32 lsr 16) land of_unsigned_int 0xFFFF))
+  in
+  let b =
+    ref Optint.(to_unsigned_int Infix.(adler32 land of_unsigned_int 0xFFFF))
   in
-  let b = ref Optint.(to_unsigned_int Infix.(adler32 land of_int 0xFFFF)) in
   let l = ref len in
   let o = ref off in
   if len = 0
@@ -124,7 +128,7 @@ let digest : type a. get:(a -> int -> char) -> a -> int -> int -> t -> t =
       b := !b mod _base ;
       a := !a mod _base) ;
     Optint.Infix.(
-      Optint.of_unsigned_int !b land (Optint.of_unsigned_int !a lsl 16)))
+      Optint.of_unsigned_int !b lor (Optint.of_unsigned_int !a lsl 16)))
 
 let unsafe_digest_bytes a o l v = digest ~get:Bytes.unsafe_get a o l v
 let digest_bytes a o l v = digest ~get:Bytes.get a o l v

test/test.ml

@@ -12,6 +12,23 @@ let make ~name (module M : Checkseum.S) input expected =
 let () =
   Alcotest.run "checkseum"
     [
+      ( "adler32",
+        [
+          make ~name:"0" (module Checkseum.Adler32) "" 1l;
+          make ~name:"1" (module Checkseum.Adler32) "\x00" 65537l;
+          make ~name:"2"
+            (module Checkseum.Adler32)
+            "\xff\xff\xff\xff" 167379965l;
+          make ~name:"3" (module Checkseum.Adler32) "123456789" 0x91E01DEl;
+          make ~name:"4"
+            (module Checkseum.Adler32)
+            (String.concat ""
+               [
+                 "\x9d\x02\x9d\x02\x90\xad\x14\x72\xb9\xb4\x44\x59\x5d\x21\x05\xb7";
+                 "\x34\x4f\x64\xe9\xa8\x5a\x3e\xd9\x91\x1f\x44\x91\xc1\x5c";
+               ])
+            0xBDE50CD1l;
+        ] );
       ( "crc32c",
         [
           make ~name:"0" (module Checkseum.Crc32c) "" 0l;