[bugfix] Fix dereferencing ancestors on new status create (#2652)

* [bugfix] Pass `latest` to dereferenceThread instead of barebones status

* only mark status orphaned if visibility suggests parent is really deleted

* tone down "not deref'd" warnings, since they represent a legit visibility situation

* remove FAQ entry for "status not deref'd yet"

internal/federation/dereferencing/status.go

@@ -222,7 +222,7 @@ func (d *Dereferencer) RefreshStatus(
 		d.dereferenceThread(ctx,
 			requestUser,
 			uri,
-			status,
+			latest,
 			statusable,
 			isNew,
 		)

internal/federation/dereferencing/thread.go

@@ -124,9 +124,34 @@ func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username
 		// Check for a returned HTTP code via error.
 		switch code := gtserror.StatusCode(err); {
 
-		// Status codes 404 and 410 incicate the status does not exist anymore.
-		// Gone (410) is the preferred for deletion, but we accept NotFound too.
-		case code == http.StatusNotFound || code == http.StatusGone:
+		// 404 may indicate deletion, but can also
+		// indicate that we don't have permission to
+		// view the status (it's followers-only and
+		// we don't follow, for example).
+		case code == http.StatusNotFound:
+			// If this reply is followers-only or stricter,
+			// we can safely assume the status it replies
+			// to is also followers only or stricter.
+			//
+			// In this case we should leave the inReplyTo
+			// URI in place for visibility filtering,
+			// and just return since we can go no further.
+			if status.Visibility == gtsmodel.VisibilityFollowersOnly ||
+				status.Visibility == gtsmodel.VisibilityMutualsOnly ||
+				status.Visibility == gtsmodel.VisibilityDirect {
+				return nil
+			}
+
+			// If the reply is public or unlisted then
+			// likely the replied-to status is/was public
+			// or unlisted and has indeed been deleted,
+			// fall through to the Gone case to clean up.
+			fallthrough
+
+		// Gone (410) definitely indicates deletion.
+		// Update the status to remove references to
+		// the now-gone parent.
+		case code == http.StatusGone:
 			l.Trace("status orphaned")
 			current.InReplyToID = ""
 			current.InReplyToURI = ""

internal/visibility/home_timeline.go

@@ -156,7 +156,7 @@ func (f *Filter) isStatusHomeTimelineable(ctx context.Context, owner *gtsmodel.A
 
 		// Check parent is deref'd.
 		if next.InReplyToID == "" {
-			log.Warnf(ctx, "status not yet deref'd: %s", next.InReplyToURI)
+			log.Debugf(ctx, "status not (yet) deref'd: %s", next.InReplyToURI)
 			return false, cache.SentinelError
 		}
 

internal/visibility/public_timeline.go

@@ -95,7 +95,7 @@ func (f *Filter) isStatusPublicTimelineable(ctx context.Context, requester *gtsm
 		// Fetch next parent to lookup.
 		parentID := parent.InReplyToID
 		if parentID == "" {
-			log.Warnf(ctx, "status not yet deref'd: %s", parent.InReplyToURI)
+			log.Debugf(ctx, "status not (yet) deref'd: %s", parent.InReplyToURI)
 			return false, cache.SentinelError
 		}