When running a controller unit test (using the $this->dispatch('/') for example), a call to $this->getRequest()->getHttpHost() in a controller returns the colon sign - ":".

To replicate:

Create the following action in a controller:

    public function colonAction() {
        $this->_helper->layout()->disableLayout();
        $this->_helper->viewRenderer->setNoRender();
        $this->getResponse()->setBody($this->getRequest()->getHttpHost());
    }

If you'll go over to that action in a browser, you'll get the appropriate host name.

Now write a test with the following method:

    public function test_colonAction() {
        $this->dispatch('/index/colon');
        self::assertEquals(':', $this->getResponse()->getBody());
    }

Running the test will result in a successful run (which means the getHttpHost method returns a : sign when run in a test).