bpo-40375: Implement imaplib.IMAP4.unselect (GH-19712)

1 files changed, 17 insertions, 0 deletions

diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index abfdd73..d9720f2 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -98,6 +98,7 @@ Commands = {
         'THREAD':       ('SELECTED',),
         'UID':          ('SELECTED',),
         'UNSUBSCRIBE':  ('AUTH', 'SELECTED'),
+        'UNSELECT':     ('SELECTED',),
         }
 
 #       Patterns to match server responses
@@ -902,6 +903,22 @@ class IMAP4:
         return self._simple_command('UNSUBSCRIBE', mailbox)
 
 
+    def unselect(self):
+        """Free server's resources associated with the selected mailbox
+        and returns the server to the authenticated state.
+        This command performs the same actions as CLOSE, except
+        that no messages are permanently removed from the currently
+        selected mailbox.
+
+        (typ, [data]) = <instance>.unselect()
+        """
+        try:
+            typ, data = self._simple_command('UNSELECT')
+        finally:
+            self.state = 'AUTH'
+        return typ, data
+
+
     def xatom(self, name, *args):
         """Allow simple extension commands
                 notified by server in CAPABILITY response.