fix null dereference when getting old title

core/structs.go

@@ -94,6 +94,9 @@ func (d *FullData) InsertFeed(new *Feed, remote string) {
 	oldFeed, ok := d.Feeds[remote]
 	if !ok || !reflect.DeepEqual(new, oldFeed) {
 		// Feeds are different, or there was never an old one
+		if oldFeed != nil && new.Title == "" && oldFeed.Title != "" {
+			new.Title = oldFeed.Title
+		}
 		d.Feeds[remote] = new
 		d.FeedsMu.Unlock()
 	} else {
@@ -104,9 +107,12 @@ func (d *FullData) InsertFeed(new *Feed, remote string) {
 // InsertPage will insert or update a core.Page in a core.FullData
 func (d *FullData) InsertPage(new *Page, remote string) {
 	d.PagesMu.Lock()
-	_, ok := d.Pages[remote]
+	oldPage, ok := d.Pages[remote]
 	if !ok || d.Pages[remote].Hash != new.Hash {
 		// pages are different, or there was never an old one
+		if oldPage != nil && new.Title == "" && oldPage.Title != "" {
+			new.Title = oldPage.Title
+		}
 		d.Pages[remote] = new
 		d.PagesMu.Unlock()
 	} else {