GODT-1021 Do not allow copy Inbox->Sent or Sent->Inbox

internal/imap/mailbox_messages.go

@@ -215,7 +215,7 @@ func (im *imapMailbox) MoveMessages(uid bool, seqSet *imap.SeqSet, targetLabel s
 	return im.labelMessages(uid, seqSet, targetLabel, true)
 }
 
-func (im *imapMailbox) labelMessages(uid bool, seqSet *imap.SeqSet, targetLabel string, move bool) error {
+func (im *imapMailbox) labelMessages(uid bool, seqSet *imap.SeqSet, targetLabel string, move bool) error { //nolint[funlen]
 	messageIDs, err := im.apiIDsFromSeqSet(uid, seqSet)
 	if err != nil || len(messageIDs) == 0 {
 		return err
@@ -230,6 +230,25 @@ func (im *imapMailbox) labelMessages(uid bool, seqSet *imap.SeqSet, targetLabel
 		return err
 	}
 
+	// Moving or copying from Inbox to Sent or from Sent to Inbox is no-op.
+	// Inbox and Sent is the same mailbox and message is showen in one or
+	// the other based on message flags.
+	// COPY operation has to be forbidden otherwise move by COPY+EXPUNGE
+	// would lead to message found only in All Mail, because COPY is no-op
+	// and EXPUNGE is translated as unlabel from the source.
+	// MOVE operation could be allowed, just it will do no change. It's better
+	// to refuse it as well so client is kept in proper state and no sync
+	// is needed.
+	isInboxOrSent := func(labelID string) bool {
+		return labelID == pmapi.InboxLabel || labelID == pmapi.SentLabel
+	}
+	if isInboxOrSent(im.storeMailbox.LabelID()) && isInboxOrSent(targetStoreMailbox.LabelID()) {
+		if im.storeMailbox.LabelID() == pmapi.InboxLabel {
+			return errors.New("move from Inbox to Sent is not allowed")
+		}
+		return errors.New("move from Sent to Inbox is not allowed")
+	}
+
 	deletedIDs := []string{}
 	allDeletedIDs, err := im.storeMailbox.GetDeletedAPIIDs()
 	if err != nil {

test/features/bridge/imap/message/copy.feature

@@ -7,10 +7,13 @@ Feature: IMAP copy messages
       | from              | to         | subject | body  | read  | deleted |
       | john.doe@mail.com | user@pm.me | foo     | hello | true  | false   |
       | jane.doe@mail.com | name@pm.me | bar     | world | false | true    |
+    And there are messages in mailbox "Sent" for "user"
+      | from              | to         | subject  | body  |
+      | john.doe@mail.com | user@pm.me | response | hello |
     And there is IMAP client logged in as "user"
-    And there is IMAP client selected in "INBOX"
 
   Scenario: Copy message to label
+    Given there is IMAP client selected in "INBOX"
     When IMAP client copies message seq "1" to "Labels/label"
     Then IMAP response is "OK"
     And mailbox "INBOX" for "user" has messages
@@ -22,6 +25,7 @@ Feature: IMAP copy messages
       | john.doe@mail.com | user@pm.me | foo     | hello | true | false   |
 
   Scenario: Copy all messages to label
+    Given there is IMAP client selected in "INBOX"
     When IMAP client copies message seq "1:*" to "Labels/label"
     Then IMAP response is "OK"
     And mailbox "INBOX" for "user" has messages
@@ -34,6 +38,7 @@ Feature: IMAP copy messages
       | jane.doe@mail.com | name@pm.me | bar     | world | false | true    |
 
   Scenario: Copy message to folder does move
+    Given there is IMAP client selected in "INBOX"
     When IMAP client copies message seq "1" to "Folders/mbox"
     Then IMAP response is "OK"
     And mailbox "INBOX" for "user" has messages
@@ -44,6 +49,7 @@ Feature: IMAP copy messages
       | john.doe@mail.com | user@pm.me | foo     | hello | true | false   |
 
   Scenario: Copy all messages to folder does move
+    Given there is IMAP client selected in "INBOX"
     When IMAP client copies message seq "1:*" to "Folders/mbox"
     Then IMAP response is "OK"
     And mailbox "INBOX" for "user" has 0 messages
@@ -51,3 +57,13 @@ Feature: IMAP copy messages
       | from              | to         | subject | body  | read  | deleted |
       | john.doe@mail.com | user@pm.me | foo     | hello | true  | false   |
       | jane.doe@mail.com | name@pm.me | bar     | world | false | true    |
+
+  Scenario: Copy message from Inbox to Sent is not possible
+    Given there is IMAP client selected in "INBOX"
+    When IMAP client copies message seq "1" to "Sent"
+    Then IMAP response is "move from Inbox to Sent is not allowed"
+
+  Scenario: Copy message from Sent to Inbox is not possible
+    Given there is IMAP client selected in "Sent"
+    When IMAP client copies message seq "1" to "INBOX"
+    Then IMAP response is "move from Sent to Inbox is not allowed"

test/features/bridge/imap/message/move.feature

@@ -8,6 +8,9 @@ Feature: IMAP move messages
       | from              | to         | subject | body  |
       | john.doe@mail.com | user@pm.me | foo     | hello |
       | jane.doe@mail.com | name@pm.me | bar     | world |
+    And there are messages in mailbox "Sent" for "user"
+      | from              | to         | subject  | body  |
+      | john.doe@mail.com | user@pm.me | response | hello |
     And there are messages in mailbox "Labels/label2" for "user"
       | from              | to         | subject | body  |
       | john.doe@mail.com | user@pm.me | baz     | hello |
@@ -87,3 +90,13 @@ Feature: IMAP move messages
       | john.doe@mail.com | user@pm.me | baz     |
     And API endpoint "PUT /mail/v4/messages/label" is called
     And API endpoint "PUT /mail/v4/messages/unlabel" is not called
+
+  Scenario: Move message from Inbox to Sent is not possible
+    Given there is IMAP client selected in "INBOX"
+    When IMAP client moves message seq "1" to "Sent"
+    Then IMAP response is "move from Inbox to Sent is not allowed"
+
+  Scenario: Move message from Sent to Inbox is not possible
+    Given there is IMAP client selected in "Sent"
+    When IMAP client moves message seq "1" to "INBOX"
+    Then IMAP response is "move from Sent to Inbox is not allowed"