#51 ConsoleReader.readLine("prompt") resets prompt permanently

When calling ConsoleReader.readLine("prompt>") the default prompt will permanently be set to "prompt>", whereas I'd expect otherwise. It somehow defeats the purpose of having a default prompt if it is overridden by that method, doesn't it?

The culprit is ConsoleReader.readLine(String, Character) which sets this.prompt to the new prompt if one is given. A simple fix would be to change the if statement around line 477 not to set this.prompt to the prompt, but rather the given prompt to this.prompt if it's null.