This variable is possibly used without initialization. Detected by valgrind.
==2312== Thread 10: ==2312== Conditional jump or move depends on uninitialised value(s) ==2312== at 0x9B8AEF: mongo::mr::State::postProcessCollection(mongo::CurOp*, mongo::ProgressMeterHolder&) (mr.cpp:462) ==2312== by 0x9BF416: mongo::mr::MapReduceCommand::run(std::string const&, mongo::BSONObj&, int, std::string&, mongo::BSONObjBuilder&, bool) (mr.cpp:1163) ==2312== by 0xA740E8: mongo::_execCommand(mongo::Command*, std::string const&, mongo::BSONObj&, int, mongo::BSONObjBuilder&, bool) (dbcommands.cpp:1776) ==2312== by 0xA74BEB: mongo::execCommand(mongo::Command*, mongo::Client&, int, char const*, mongo::BSONObj&, mongo::BSONObjBuilder&, bool) (dbcommands.cpp:1880) ==2312== by 0xA753AF: mongo::_runCommands(char const*, mongo::BSONObj&, mongo::_BufBuilder<mongo::TrivialAllocator>&, mongo::BSONObjBuilder&, bool, int) (dbcommands.cpp:1949) ==2312== by 0x9FB230: mongo::runCommands(char const*, mongo::BSONObj&, mongo::CurOp&, mongo::_BufBuilder<mongo::TrivialAllocator>&, mongo::BSONObjBuilder&, bool, int) (query.cpp:42) ==2312== by 0x9FF083: mongo::runQuery(mongo::Message&, mongo::QueryMessage&, mongo::CurOp&, mongo::Message&) (query.cpp:779) ==2312== by 0x9A169D: mongo::receivedQuery(mongo::Client&, mongo::DbResponse&, mongo::Message&) (instance.cpp:225) ==2312== by 0x9A23A2: mongo::assembleResponse(mongo::Message&, mongo::DbResponse&, mongo::HostAndPort const&) (instance.cpp:362) ==2312== by 0x8CE6FE: mongo::MyMessageHandler::process(mongo::Message&, mongo::AbstractMessagingPort*, mongo::LastError*) (db.cpp:184) ==2312== by 0xAD7683: mongo::pms::threadRun(mongo::MessagingPort*) (message_server_port.cpp:77) ==2312== by 0x33C5206CCA: start_thread (in /lib64/libpthread-2.13.so) ==2312==