/topic (no args) could return the current topic for the current channel.

[EntityReborn]

From what I'm aware of, /topic expects arguments. Triggering /topic without arguments might trigger the topic to be shown instead of set.

A possible fix might be changing the lines 131 and 132 of /js/irc/commands.js to the following:

cmd_TOPIC: [true, 1, 0, function(args) {
    this.send("TOPIC " + this.getActiveWindow().name + (args?" :" + args[0]:""));

[mrflea]

It turns out that this is a bit hairier than expected. Passing through the TOPIC command raw causes it to be swallowed by the existing RPL_TOPIC handler with nothing printed to the channel. We don't stash the text of the content anywhere locally, either (except the HTML element the text is stored in), so we can't just return something already received.

I'll take another look at some point in the future. I'll probably end up changing the RPL_TOPIC handler to not swallow the topic message each time, but doing so without printing the topic to the channel window on join will be slightly annoying.