877    WriteUnitOfWork wunit(txn);
878    Collection* collection = ctx.db()->getCollection( ns );
879    if ( !collection ) {
880        collection = ctx.db()->createCollection( txn, ns );
881        verify( collection );
882        repl::logOp(txn,
883                    "c",
884                    (ctx.db()->name() + ".$cmd").c_str(),
885                    BSON("create" << nsToCollectionSubstring(ns)));
886    }
887
888    StatusWith<RecordId> status = collection->insertDocument( txn, js, true );
889    uassertStatusOK( status.getStatus() );
890    repl::logOp(txn, "i", ns, js);
891    wunit.commit();

Rollback of logOp not currently allowed (SERVER-15192)
Fatal Assertion 18805

#0  0x00007ffff7bcc20b in raise (sig=5) at ../nptl/sysdeps/unix/sysv/linux/pt-raise.c:37
#1  0x00000000018d53ce in mongo::breakpoint () at src/mongo/util/debugger.cpp:63
#2  0x00000000018ca463 in mongo::fassertFailed (msgid=18805) at src/mongo/util/assert_util.cpp:165
#3  0x00000000015f6f54 in mongo::repl::RollbackPreventer::rollback (this=0x30cc428) at src/mongo/db/repl/oplog.cpp:389
#4  0x00000000017005b8 in mongo::DurRecoveryUnit::rollbackInnermostChanges (this=0x32ce340) at src/mongo/db/storage/mmap_v1/dur_recovery_unit.cpp:174
#5  0x00000000016ffcc6 in mongo::DurRecoveryUnit::endUnitOfWork (this=0x32ce340) at src/mongo/db/storage/mmap_v1/dur_recovery_unit.cpp:78
#6  0x0000000001141854 in mongo::WriteUnitOfWork::~WriteUnitOfWork (this=0x7ffff7fcc1a0, __in_chrg=<optimized out>) at src/mongo/db/operation_context.h:156
#7  0x000000000144d9a6 in mongo::checkAndInsert (txn=0x7ffff7fcc7d0, ctx=..., ns=0x4d82814 "test.logop_rollback", js=...) at src/mongo/db/instance.cpp:892
#8  0x000000000144eff3 in mongo::receivedInsert (txn=0x7ffff7fcc7d0, m=..., op=...) at src/mongo/db/instance.cpp:1078
#9  0x000000000144a341 in mongo::assembleResponse (txn=0x7ffff7fcc7d0, m=..., dbresponse=..., remote=..., fromDBDirectClient=false) at src/mongo/db/instance.cpp:460
#10 0x0000000001142274 in mongo::MyMessageHandler::process (this=0x30cc1c8, m=..., port=0x30f2580, le=0x34102d0) at src/mongo/db/db.cpp:206
#11 0x00000000018f34d4 in mongo::PortMessageServer::handleIncomingMsg (arg=0x30f2580) at src/mongo/util/net/message_server_port.cpp:229
#12 0x00007ffff7bc4182 in start_thread (arg=0x7ffff7fcd700) at pthread_create.c:312
#13 0x00007ffff6cc500d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111