From ee2acf8b98d3bdca58db12787e4a9878c817eb62 Mon Sep 17 00:00:00 2001
From: Ahmad Ansori Palembani <palembani@gmail.com>
Date: Sat, 14 Dec 2024 14:29:10 +0700
Subject: [PATCH] fix: Delete duplicate chapters

---
 .../kanade/tachiyomi/util/chapter/ChapterSourceSync.kt   | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt b/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt
index bda3a024bd..66e73646a9 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/util/chapter/ChapterSourceSync.kt
@@ -107,12 +107,17 @@ suspend fun syncChaptersWithSource(
         it.chapter_number = ChapterRecognition.parseChapterNumber(it.name, manga.title, it.chapter_number)
     }
 
-    // Chapters from the db not in the source.
-    val toDelete = dbChapters.filterNot { dbChapter ->
+    val duplicates = dbChapters.groupBy { it.url }
+        .filter { it.value.size > 1 }
+        .flatMap { (_, chapters) ->
+            chapters.drop(1)
+        }
+    val notInSource = dbChapters.filterNot { dbChapter ->
         sourceChapters.any { sourceChapter ->
             dbChapter.url == sourceChapter.url
         }
     }
+    val toDelete = duplicates + notInSource
 
     // Return if there's nothing to add, delete or change, avoid unnecessary db transactions.
     if (toAdd.isEmpty() && toDelete.isEmpty() && toChange.isEmpty()) {