File 2931-tar_SUITE-Use-rand-for-generating-random-b... of Package erlang

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File 2931-tar_SUITE-Use-rand-for-generating-random-bytes.patch of Package erlang (Revision 371fc947ce89baa340e0441f200e4667)

Currently displaying revision 371fc947ce89baa340e0441f200e4667 , Show latest

From 94643e66fbbabe7bd2c8816fd7a914557fb71b3c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Thu, 5 May 2022 07:41:01 +0200
Subject: [PATCH 1/3] tar_SUITE: Use rand for generating random bytes

---
 lib/stdlib/test/tar_SUITE.erl | 34 +++-------------------------------
 1 file changed, 3 insertions(+), 31 deletions(-)

diff --git a/lib/stdlib/test/tar_SUITE.erl b/lib/stdlib/test/tar_SUITE.erl
index 4eac9c8162..cce73d7de9 100644
--- a/lib/stdlib/test/tar_SUITE.erl
+++ b/lib/stdlib/test/tar_SUITE.erl
@@ -113,8 +113,8 @@ borderline_test(Size, TempDir, IsUstar) ->
     Name = filename:join(TempDir, Prefix++SizeList),
 
     %% Create a file and archive it.
-    X0 = erlang:monotonic_time(),
-    ok = file:write_file(Name, random_byte_list(X0, Size)),
+    RandomBytes = rand:bytes(Size),
+    ok = file:write_file(Name, RandomBytes),
     ok = erl_tar:create(Archive, [Name]),
     ok = file:delete(Name),
 
@@ -125,7 +125,7 @@ borderline_test(Size, TempDir, IsUstar) ->
 
     %% Verify contents of extracted file.
     {ok, Bin} = file:read_file(Name),
-    true = match_byte_list(X0, binary_to_list(Bin)),
+    RandomBytes = Bin,
 
     %% Verify that Unix tar can read it.
     case IsUstar of
@@ -199,34 +199,6 @@ make_cmd(Cmd) ->
 	{unix, _}  -> lists:concat(["sh -c '",  Cmd,  "'"])
     end.
 
-%% Verifies a random byte list.
-
-match_byte_list(X0, [Byte|Rest]) ->
-    X = next_random(X0),
-    case (X bsr 26) band 16#ff of
-	Byte -> match_byte_list(X, Rest);
-	_ -> false
-    end;
-match_byte_list(_, []) ->
-    true.
-
-%% Generates a random byte list.
-
-random_byte_list(X0, Count) ->
-    random_byte_list(X0, Count, []).
-
-random_byte_list(X0, Count, Result) when Count > 0->
-    X = next_random(X0),
-    random_byte_list(X, Count-1, [(X bsr 26) band 16#ff|Result]);
-random_byte_list(_X, 0, Result) ->
-    lists:reverse(Result).
-
-%% This RNG is from line 21 on page 102 in Knuth: The Art of Computer Programming,
-%% Volume II, Seminumerical Algorithms.
-
-next_random(X) ->
-    (X*17059465+1) band 16#fffffffff.
-
 %% Test the 'atomic' operations: create/extract/table, on compressed
 %% and uncompressed archives.
 %% Also test the 'cooked' option.
-- 
2.35.3

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File 2931-tar_SUITE-Use-rand-for-generating-random-bytes.patch of Package erlang (Revision 371fc947ce89baa340e0441f200e4667)

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