check for new email doesn't work if another imap client is accessing the mailbox

[Paul]

Hi,

We're running a pilot with roundcube, and one of our customers has reported that new email doesn't show up in his inbox.
This seems to be caused by the customer having another IMAP client running.

I've tried opening the same inbox in two instances of roundcube in two browsers, and sending an email to myself. The message only showed up in one of the instances. From the source it looks like check_recent.inc uses a 'select' command and then uses the 'recent' response to check for new messsages. However, the 'select' command unsets the recent flag. So I think roundcube should use an 'examine' command (seems to be in the code already in the iil_CheckForRecent function) instead of a 'select' command, and also it should use the 'exists' response instead of the 'recent' response.