backends: send MessageInfoError on header fetching error

When an error is encountered fetching a header, the backends respond
with a type.Error worker message. On receipt of this message, the UI
deletes all pending headers. The headers are all requested again as they
remain on the screen, resulting in an infinite request loop - and an
infinite logging loop. The user only ever sees the spinner unless they
check the logs.

A previous commit intended to fix this, however it introduced a
regression where any message that was part of the fetch request would
also be marked as erroneous. This commit is reverted with commit
2aad2fea7d36 ("msgstore: revert 9fdc7acf5b48").

Send an erroneous message info message from the backend when an error is
encountered for a specific UID.

Fixes: 01f80721e283 ("msgstore: post MessageInfo on erroneous fetch")
Signed-off-by: Tim Culverhouse <tim@timculverhouse.com>
Acked-by: Robin Jarry <robin@jarry.cc>

5 files changed, 20 insertions, 8 deletions

diff --git a/worker/imap/fetch.go b/worker/imap/fetch.go
index d675ed17..79c9148b 100644
--- a/worker/imap/fetch.go
+++ b/worker/imap/fetch.go
@@ -50,10 +50,7 @@ func (imapw *IMAPWorker) handleFetchMessageHeaders(
 			if err != nil {
 				logging.Errorf(
 					"message %d: could not read header: %v", _msg.Uid, err)
-				imapw.worker.PostMessage(&types.Error{
-					Message: types.RespondTo(msg),
-					Error:   err,
-				}, nil)
+				imapw.worker.PostMessageInfoError(msg, _msg.Uid, err)
 				return nil
 			}
 			header := &mail.Header{Header: message.Header{Header: textprotoHeader}}
diff --git a/worker/maildir/worker.go b/worker/maildir/worker.go
index 0ece323b..d0619ad4 100644
--- a/worker/maildir/worker.go
+++ b/worker/maildir/worker.go
@@ -479,7 +479,7 @@ func (w *Worker) handleFetchMessageHeaders(
 		info, err := w.msgInfoFromUid(uid)
 		if err != nil {
 			logging.Errorf("could not get message info: %w", err)
-			w.err(msg, err)
+			w.worker.PostMessageInfoError(msg, uid, err)
 			continue
 		}
 		w.worker.PostMessage(&types.MessageInfo{
diff --git a/worker/mbox/worker.go b/worker/mbox/worker.go
index c5c70821..10a94cdc 100644
--- a/worker/mbox/worker.go
+++ b/worker/mbox/worker.go
@@ -152,7 +152,7 @@ func (w *mboxWorker) handleMessage(msg types.WorkerMessage) error {
 			}
 			msgInfo, err := lib.MessageInfo(m)
 			if err != nil {
-				reterr = err
+				w.worker.PostMessageInfoError(msg, uid, err)
 				break
 			} else {
 				w.worker.PostMessage(&types.MessageInfo{
diff --git a/worker/notmuch/worker.go b/worker/notmuch/worker.go
index 903460eb..2c8cc4f2 100644
--- a/worker/notmuch/worker.go
+++ b/worker/notmuch/worker.go
@@ -315,13 +315,13 @@ func (w *worker) handleFetchMessageHeaders(
 		m, err := w.msgFromUid(uid)
 		if err != nil {
 			logging.Errorf("could not get message: %w", err)
-			w.err(msg, err)
+			w.w.PostMessageInfoError(msg, uid, err)
 			continue
 		}
 		err = w.emitMessageInfo(m, msg)
 		if err != nil {
 			logging.Errorf("could not emit message info: %w", err)
-			w.err(msg, err)
+			w.w.PostMessageInfoError(msg, uid, err)
 			continue
 		}
 	}
diff --git a/worker/types/worker.go b/worker/types/worker.go
index ba396aa3..ad359494 100644
--- a/worker/types/worker.go
+++ b/worker/types/worker.go
@@ -4,6 +4,7 @@ import (
 	"sync/atomic"
 
 	"git.sr.ht/~rjarry/aerc/logging"
+	"git.sr.ht/~rjarry/aerc/models"
 )
 
 var lastId int64 = 1 // access via atomic
@@ -104,3 +105,17 @@ func (worker *Worker) ProcessAction(msg WorkerMessage) WorkerMessage {
 	}
 	return msg
 }
+
+// PostMessageInfoError posts a MessageInfo message to the worker when an
+// error was encountered fetching the message header
+func (worker *Worker) PostMessageInfoError(msg WorkerMessage, uid uint32, err error) {
+	worker.PostMessage(&MessageInfo{
+		Info: &models.MessageInfo{
+			Envelope: &models.Envelope{},
+			Flags:    []models.Flag{models.SeenFlag},
+			Uid:      uid,
+			Error:    err,
+		},
+		Message: RespondTo(msg),
+	}, nil)
+}