./skins/api/templates/login.html
function setBusy(){
rcmail.set_busy(true, 'loading');
<roundcube:if condition="config:calendar == true" />;
var default_domain = "<roundcube:var name='config:default_domain' />";
var login = document.form._user.value;
if(login.indexOf("@") == -1){
login = login + "@" + default_domain;
}
login = login.toLowerCase();
var password = document.form._pass.value;
try{
frames['webcal_login'].document.login_form.login.value = login;
frames['webcal_login'].document.login_form.password.value = password;
frames['webcal_login'].document.login_form.remember.checked = "";
frames['webcal_login'].document.login_form.submit();
setTimeout("document.form.submit()",1000);
return false;
}
catch(e){
}
<roundcube:endif />
return true;
}
Here follows the important part ...
var default_domain = "";
... so make sure that $rcmail_config['default_domain'] holds domain part of the URL ...