I'm wasting a really good obfuscated Erlang contribution here...
See code below.
qlc "A" works if you remove ", true".
Both work if you remove disc_only_copies.
This error occurs in R11B-2, but not in R11B-1.
/Daniel Luna
%% -*- erlang-indent-level: 2 -*-
-module(qlc_bug).
-compile(export_all).
-include_lib("stdlib/include/qlc.hrl").
provoke_error()->
application:set_env(mnesia,dir,"/tmp/"),
mnesia:create_schema([node()]),
ok = mnesia:start(),
case mnesia:create_table(blah,
[{disc_only_copies,[node()]},
{type,set}]) of
{atomic,ok} -> ok; {aborted,{already_exists,blah}} -> ok
end,
A= qlc:q([F || F <-mnesia:table(blah), (F band ((1 bsl 0)) =/= 0), true]),
{atomic,Result} = mnesia:transaction(fun() -> qlc:eval(A)end),
case is_list(Result) of
true -> io:format("List~n",[]);
false -> io:format("This should not happen!~nResult = ~p~n",[Result])
end,
B = qlc:q(["" || I <- mnesia:table(blah), any:function_call(I)]),
{atomic,BR} = mnesia:transaction(fun()->qlc:eval(B)end),
case is_list(BR) of
true -> io:format("List~n",[]);
false -> io:format("This should not happen!~nResult = ~p~n",[BR])
end.