Comment 3 for bug 1245597

I'm reopening this bug because there's still something strange going on here. I have the following code in systemimage/download.py just before I call .createDownloadGroup():

        if len(downloads) == 0:
            # Nothing to download. See LP: #1245597.
            return

I tried removing this since it ought to be unnecessary, but without this code, udm seems to stop sending signals no DBus. I get tons of TimeoutErrors without this code, and that only happens if no other `error`, `canceled`, or `finished` signal is received within 10 minutes. With the short-circuit, everything works great, and I've confirmed this multiple times.