This is from MRC. This one may be easy to change, since it's probably a matter of deleting code.
Consider a folder collection on the server defined as "" (thus all mailboxes). The server returns the following:
* LIST (\HasNoChildren) "/" boxA
* LIST (\HasChildren \NoSelect) "/" dirB
* LIST (\HasNoChildren) "/" INBOX
* LIST (\HasChildren) "/" boxC
In the Alpine FOLDER LIST view, we will see:
INBOX/ boxA[/] dirB/ boxC[/]
Since boxA and boxC are displayed identically, it appears that Alpine doesn't pay any attention to the children attributes. I'm pretty sure that I added support for children attributes in later versions of UW IMAP; they'd be called LATT_HASCHILDREN and LATT_HASNOCHILDREN.
However, the listing for INBOX is bizarre. I'm guessing that there is explicit code in Alpine to make it impossible to access INBOX as a mailbox in a top-level folder collection, because if the folder collection is #mail/ we get
* LIST (\HasNoChildren) "/" #mail/boxA
* LIST (\HasChildren \NoSelect) "/" #mail/dirB
* LIST (\HasNoChildren) "/" #mail/INBOX
* LIST (\HasChildren) "/" #mail/boxC
and we get the expected FOLDER LIST view:
INBOX[/] boxA[/] dirB/ boxC[/]
I never understood why Alpine (and Pine before it) felt that it was so important to exclude INBOX from a top-level folder collection list. Apparently the presumption is that the INBOX would be listed in incoming-folders, but that is not guaranteed to be the case.