GODT-1165: Handle UID FETCH with sequence range of empty mailbox

internal/store/mailbox_ids.go

@@ -38,6 +38,11 @@ func (storeMailbox *Mailbox) GetAPIIDsFromUIDRange(start, stop uint32) (apiIDs [
 		b := storeMailbox.txGetIMAPIDsBucket(tx)
 		c := b.Cursor()
 
+		// GODT-1153 If the mailbox is empty we should reply BAD to client.
+		if uid, _ := c.Last(); uid == nil {
+			return nil
+		}
+
 		// If the start range is a wildcard, the range can only refer to the last message in the mailbox.
 		if start == 0 {
 			_, apiID := c.Last()
@@ -74,6 +79,11 @@ func (storeMailbox *Mailbox) GetAPIIDsFromSequenceRange(start, stop uint32) (api
 		b := storeMailbox.txGetIMAPIDsBucket(tx)
 		c := b.Cursor()
 
+		// GODT-1153 If the mailbox is empty we should reply BAD to client.
+		if uid, _ := c.Last(); uid == nil {
+			return nil
+		}
+
 		// If the start range is a wildcard, the range can only refer to the last message in the mailbox.
 		if start == 0 {
 			_, apiID := c.Last()
@@ -318,5 +328,10 @@ func (storeMailbox *Mailbox) GetUIDByHeader(header *mail.Header) (foundUID uint3
 
 func (storeMailbox *Mailbox) txGetFinalUID(b *bolt.Bucket) uint32 {
 	uid, _ := b.Cursor().Last()
+
+	if uid == nil {
+		panic(errors.New("cannot get final UID of empty mailbox"))
+	}
+
 	return btoi(uid)
 }

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

@@ -27,7 +27,7 @@ Feature: IMAP fetch messages
     Then IMAP response is "OK"
     And IMAP response has 5 messages
 
-  Scenario: Fetch first few messages of inbox
+  Scenario: Fetch first few messages of inbox by UID
     Given there are 10 messages in mailbox "INBOX" for "user"
     And there is IMAP client logged in as "user"
     And there is IMAP client selected in "INBOX"
@@ -108,12 +108,22 @@ Feature: IMAP fetch messages
     And IMAP response has 10 messages
 
   # This test is wrong! RFC says it should return "BAD" (GODT-1153).
-  Scenario: Fetch of empty mailbox
+  Scenario Outline: Fetch range of empty mailbox
     Given there is IMAP client logged in as "user"
     And there is IMAP client selected in "Folders/mbox"
-    When IMAP client fetches "1:*"
+    When IMAP client fetches "<range>"
     Then IMAP response is "OK"
     And IMAP response has 0 messages
+    When IMAP client fetches by UID "<range>"
+    Then IMAP response is "OK"
+    And IMAP response has 0 messages
+
+    Examples:
+      | range |
+      | 1     |
+      | 1,5,6 |
+      | 1:*   |
+      | *     |
 
   Scenario: Fetch of big mailbox
     Given there are 100 messages in mailbox "Folders/mbox" for "user"
@@ -123,7 +133,26 @@ Feature: IMAP fetch messages
     Then IMAP response is "OK"
     And IMAP response has 100 messages
 
+  Scenario: Fetch of big mailbox by UID
+    Given there are 100 messages in mailbox "Folders/mbox" for "user"
+    And there is IMAP client logged in as "user"
+    And there is IMAP client selected in "Folders/mbox"
+    When IMAP client fetches by UID "1:*"
+    Then IMAP response is "OK"
+    And IMAP response has 100 messages
+
   Scenario: Fetch returns also messages that are marked as deleted
+    Given there are messages in mailbox "Folders/mbox" for "user"
+      | from              | to         | subject | body  | read  | starred | deleted |
+      | john.doe@mail.com | user@pm.me | foo     | hello | false | false   | false   |
+      | jane.doe@mail.com | name@pm.me | bar     | world | true  | true    | true    |
+    And there is IMAP client logged in as "user"
+    And there is IMAP client selected in "Folders/mbox"
+    When IMAP client fetches "1:*"
+    Then IMAP response is "OK"
+    And IMAP response has 2 message
+
+  Scenario: Fetch by UID returns also messages that are marked as deleted
     Given there are messages in mailbox "Folders/mbox" for "user"
       | from              | to         | subject | body  | read  | starred | deleted |
       | john.doe@mail.com | user@pm.me | foo     | hello | false | false   | false   |