There is an assert in `CWalletTx::RelayWalletTransaction` that gets hit.  All other code paths check `fBroadcastTransactions` before getting to `CWallet::ResendWalletTransactionsBefore` except the rpc call `resendwalletransactions`.

It's an easy fix, but we just need to decide whether to throw an error or return an empty array of rebroadcasted transaction ids.

Should be fixed for 0.15.
{
    CWallet * const pwallet = GetWalletForJSONRPCRequest(request);
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() < 1 || request.params.size() > 2)
        throw std::runtime_error(
            "lockunspent unlock ([{\"txid\":\"txid\",\"vout\":n},...])\n"
            "\nUpdates list of temporarily unspendable outputs.\n"
            "Temporarily lock (unlock=false) or unlock (unlock=true) specified transaction outputs.\n"
            "If no transaction outputs are specified when unlocking then all current locked transaction outputs are unlocked.\n"
            "A locked transaction output will not be chosen by automatic coin selection, when spending bitcoins.\n"
            "Locks are stored in memory only. Nodes start with zero locked outputs, and the locked output list\n"
            "is always cleared (by virtue of process exit) when a node stops or fails.\n"
            "Also see the listunspent call\n"
            "\nArguments:\n"
            "1. unlock            (boolean, required) Whether to unlock (true) or lock (false) the specified transactions\n"
            "2. \"transactions\"  (string, optional) A json array of objects. Each object the txid (string) vout (numeric)\n"
            "     [           (json array of json objects)\n"
            "       {\n"
            "         \"txid\":\"id\",    (string) The transaction id\n"
            "         \"vout\": n         (numeric) The output number\n"
            "       }\n"
            "       ,...\n"
            "     ]\n"
            "\nResult:\n"
            "true|false    (boolean) Whether the command was successful or not\n"
            "\nExamples:\n"
            "\nList the unspent transactions\n"