fix: Use previously cached literal in fetch keywords

When fetching messages with the keywords RFC822, RFC822Header and
RFC822Text we were retrieving the literal from the store again rather
than using the cached version as originally intended.

internal/state/mailbox_fetch.go

@@ -47,8 +47,14 @@ func (m *Mailbox) Fetch(ctx context.Context, seq *proto.SequenceSet, attributes
 					setSeen = true
 				}
 
+				if attribute.Keyword == proto.FetchKeyword_FetchKWRFC822 ||
+					attribute.Keyword == proto.FetchKeyword_FetchKWRFC822Header ||
+					attribute.Keyword == proto.FetchKeyword_FetchKWRFC822Text {
+					needsLiteral = true
+				}
+
 				op := func(snapMessage snapMsgWithSeq, message *ent.Message, literal []byte) (response.Item, error) {
-					return m.fetchKeyword(snapMessage, message, attribute.Keyword)
+					return m.fetchKeyword(snapMessage, message, attribute.Keyword, literal)
 				}
 
 				operations = append(operations, op)
@@ -162,7 +168,7 @@ func (m *Mailbox) Fetch(ctx context.Context, seq *proto.SequenceSet, attributes
 	return nil
 }
 
-func (m *Mailbox) fetchKeyword(msg snapMsgWithSeq, message *ent.Message, keyword proto.FetchKeyword) (response.Item, error) {
+func (m *Mailbox) fetchKeyword(msg snapMsgWithSeq, message *ent.Message, keyword proto.FetchKeyword, literal []byte) (response.Item, error) {
 	switch keyword {
 	case proto.FetchKeyword_FetchKWEnvelope:
 		return response.ItemEnvelope(message.Envelope), nil
@@ -174,16 +180,16 @@ func (m *Mailbox) fetchKeyword(msg snapMsgWithSeq, message *ent.Message, keyword
 		return response.ItemInternalDate(message.Date), nil
 
 	case proto.FetchKeyword_FetchKWRFC822:
-		return m.fetchRFC822(msg.ID.InternalID)
+		return m.fetchRFC822(literal)
 
 	case proto.FetchKeyword_FetchKWRFC822Header:
-		return m.fetchRFC822Header(msg.ID.InternalID)
+		return m.fetchRFC822Header(literal)
 
 	case proto.FetchKeyword_FetchKWRFC822Size:
 		return response.ItemRFC822Size(message.Size), nil
 
 	case proto.FetchKeyword_FetchKWRFC822Text:
-		return m.fetchRFC822Text(msg.ID.InternalID)
+		return m.fetchRFC822Text(literal)
 
 	case proto.FetchKeyword_FetchKWBody:
 		return response.ItemBody(message.Body), nil
@@ -199,32 +205,17 @@ func (m *Mailbox) fetchKeyword(msg snapMsgWithSeq, message *ent.Message, keyword
 	}
 }
 
-func (m *Mailbox) fetchRFC822(messageID imap.InternalMessageID) (response.Item, error) {
-	literal, err := m.state.getLiteral(messageID)
-	if err != nil {
-		return nil, err
-	}
-
+func (m *Mailbox) fetchRFC822(literal []byte) (response.Item, error) {
 	return response.ItemRFC822Literal(literal), nil
 }
 
-func (m *Mailbox) fetchRFC822Header(messageID imap.InternalMessageID) (response.Item, error) {
-	literal, err := m.state.getLiteral(messageID)
-	if err != nil {
-		return nil, err
-	}
-
+func (m *Mailbox) fetchRFC822Header(literal []byte) (response.Item, error) {
 	section := rfc822.Parse(literal)
 
 	return response.ItemRFC822Header(section.Header()), nil
 }
 
-func (m *Mailbox) fetchRFC822Text(messageID imap.InternalMessageID) (response.Item, error) {
-	literal, err := m.state.getLiteral(messageID)
-	if err != nil {
-		return nil, err
-	}
-
+func (m *Mailbox) fetchRFC822Text(literal []byte) (response.Item, error) {
 	section := rfc822.Parse(literal)
 
 	return response.ItemRFC822Text(section.Body()), nil