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() != 2)
        throw std::runtime_error(
            "signmessage \"address\" \"message\"\n"
            "\nSign a message with the private key of an address"
            + HelpRequiringPassphrase(pwallet) + "\n"
            "\nArguments:\n"
            "1. \"address\"         (string, required) The bitcoin address to use for the private key.\n"
            "2. \"message\"         (string, required) The message to create a signature of.\n"
            "\nResult:\n"
            "\"signature\"          (string) The signature of the message encoded in base 64\n"
            "\nExamples:\n"
            "\nUnlock the wallet for 30 seconds\n"
            + HelpExampleCli("walletpassphrase", "\"mypassphrase\" 30") +