* fix not invoking ThreadLatestReplierSaver.SaveFromThread() for ne…

…w threads leading to trying to save duplicate latest repliers as related entity of new thread @ `ThreadSaver.Save()`

* now passing variable `maybeExistingAndNewPosts` instead of `existingAndNewPosts` as the param of callback `onBeforeSaveRevision()` @ `PostSaver.Save()`
@ c#/crawler

c#/crawler/src/Tieba/Crawl/Saver/Post/PostSaver.cs

@@ -26,7 +26,7 @@ protected SaverChangeSet<TPost> Save<TRevision>(
         Func<TPost, PostId> postIdSelector,
         Func<TPost, TRevision> revisionFactory,
         Func<IQueryable<TPost>, IQueryable<TPost>> postQueryTransformer,
-        Action<IEnumerable<ExistingAndNewEntity<TPost>>>? onBeforeSaveRevision = null)
+        Action<IEnumerable<MaybeExistingAndNewEntity<TPost>>>? onBeforeSaveRevision = null)
         where TRevision : TBaseRevision
     {
         var existingPosts = postQueryTransformer(db.Set<TPost>().AsTracking()).ToList();
@@ -41,7 +41,7 @@ from existingPost in existingPostsWithSameId.DefaultIfEmpty()
 
         var existingAndNewPosts = SaveNewEntities(db, maybeExistingAndNewPosts).ToList();
         SaveExistingEntities(db, existingAndNewPosts);
-        onBeforeSaveRevision?.Invoke(existingAndNewPosts);
+        onBeforeSaveRevision?.Invoke(maybeExistingAndNewPosts);
         SaveExistingEntityRevisions(db, revisionFactory, existingAndNewPosts);
         return new(postIdSelector, existingPostsBeforeMerge, Posts.Values, existingPosts);
     }

c#/crawler/src/Tieba/Crawl/Saver/Post/ThreadSaver.cs

@@ -16,9 +16,9 @@ public override SaverChangeSet<ThreadPost> Save(CrawlerDbContext db) => Save(db,
         posts => posts
             .Where(th => Posts.Keys.Contains(th.Tid))
             .Include(th => th.LatestReplier),
-        existingAndNewPosts =>
+        maybeEntities =>
             PostSaveHandlers += threadLatestReplierSaver.SaveFromThread(db,
-                existingAndNewPosts.Select(t => t.Existing).ToList()));
+                maybeEntities.Select(entity => entity.Existing ?? entity.New).ToList()));
 }
 public partial class ThreadSaver
 {