1 files changed, 67 insertions, 0 deletions
diff --git a/lib/hipe/test/bs_SUITE_data/bs_pmatch_bugs.erl b/lib/hipe/test/bs_SUITE_data/bs_pmatch_bugs.erl
new file mode 100644
index 0000000000..b280705a47
--- /dev/null
+++ b/lib/hipe/test/bs_SUITE_data/bs_pmatch_bugs.erl
@@ -0,0 +1,67 @@
+%% -*- erlang-indent-level: 2 -*-
+%%--------------------------------------------------------------------
+-module(bs_pmatch_bugs).
+
+-export([test/0]).
+
+test() ->
+  Bin = <<"123.123">>,
+  <<49,50,51>> = lex_digits1(Bin, 1, []),
+  <<49,50,51>> = lex_digits2(Bin, 1, []),
+  ok = var_bind_bug(<<1, 2, 3, 4, 5, 6, 7, 8>>),
+  ok.
+
+%%--------------------------------------------------------------------
+%% One of the lex_digits functions below gave incorrect results due to
+%% incorrect pattern matching compilation of binaries by the byte code
+%% compiler. Fixed by Bjorn Gustavsson on 5/3/2003.
+%% --------------------------------------------------------------------
+lex_digits1(<<$., Rest/binary>>, _Val, _Acc) ->
+  Rest;
+lex_digits1(<<N, Rest/binary>>, Val, Acc) when N >= $0, N =< $9 ->
+  lex_digits1(Rest, Val * 10 + dec(N), Acc);
+lex_digits1(_Other, _Val, _Acc) ->
+  not_ok.
+
+lex_digits2(<<N, Rest/binary>>,Val, Acc) when N >= $0, N =< $9 ->
+  lex_digits2(Rest, Val * 10 + dec(N), Acc);
+lex_digits2(<<$., Rest/binary>>, _Val, _Acc) ->
+  Rest;
+lex_digits2(_Other, _Val, _Acc) ->
+  not_ok.
+
+dec(A) ->
+  A - $0.
+
+%%--------------------------------------------------------------------
+%% From: Bernard Duggan
+%% Date: 11/3/2011
+%%
+%% I've just run into an interesting little bit of behaviour that
+%% doesn't seem quite right.  erlc gives me the warning
+%%
+%%   43: Warning: this clause cannot match because a previous
+%%		  clause at line 42 always matches
+%%	 (line 42 is the "B -> wrong;" line).
+%%
+%% And sure enough, if you run test/0 you get 'wrong' back.
+%%
+%% That, in itself, is curious to me since by my understanding B should
+%% be bound by the function header, and have no guarantee of being the
+%% same as A.  I can't see how it could be unbound.
+%%
+%% Doubly curious, is that if I stop using B as the size specifier of C,
+%% like this:
+%%
+%%   match(<<A:1/binary, B:8/integer, _C:1/binary, _Rest/binary>>) ->
+%%
+%% the warning goes away.  And the result becomes 'ok' (in spite of
+%% nothing in the body having changed, and the only thing changing in
+%% the header being the size of an unused variable at the tail of the
+%% binary).
+%%--------------------------------------------------------------------
+var_bind_bug(<<A:1/binary, B:8/integer, _C:B/binary, _Rest/binary>>) ->
+  case A of
+    B -> wrong;
+    _ -> ok
+  end.