From 90d3a1dbc316f41917f14fd96b4800eecb07ee56 Mon Sep 17 00:00:00 2001
From: Gauthier Roebroeck <gauthier.roebroeck@gmail.com>
Date: Thu, 26 Mar 2026 17:27:17 +0800
Subject: [PATCH] fix: epub extension could get lost during book restoration

---
 .../domain/persistence/MediaRepository.kt     |  8 +++++
 .../domain/service/LibraryContentLifecycle.kt |  4 +--
 .../infrastructure/jooq/main/MediaDao.kt      | 34 ++++++++++++++++---
 3 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/komga/src/main/kotlin/org/gotson/komga/domain/persistence/MediaRepository.kt b/komga/src/main/kotlin/org/gotson/komga/domain/persistence/MediaRepository.kt
index b781d001..5511e4eb 100644
--- a/komga/src/main/kotlin/org/gotson/komga/domain/persistence/MediaRepository.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/domain/persistence/MediaRepository.kt
@@ -24,6 +24,14 @@ interface MediaRepository {
 
   fun update(media: Media)
 
+  /**
+   * Performs a full copy of a Media, including MediaExtension, pages, and files.
+   */
+  fun copy(
+    fromBookId: String,
+    toBookId: String,
+  )
+
   fun delete(bookId: String)
 
   fun delete(bookIds: Collection<String>)
diff --git a/komga/src/main/kotlin/org/gotson/komga/domain/service/LibraryContentLifecycle.kt b/komga/src/main/kotlin/org/gotson/komga/domain/service/LibraryContentLifecycle.kt
index 9315653c..3bab7cf7 100644
--- a/komga/src/main/kotlin/org/gotson/komga/domain/service/LibraryContentLifecycle.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/domain/service/LibraryContentLifecycle.kt
@@ -381,9 +381,7 @@ class LibraryContentLifecycle(
           logger.info { "Match found, restore $match into $bookToAdd" }
           transactionTemplate.executeWithoutResult {
             // copy media
-            mediaRepository.findById(match.id).let { deleted ->
-              mediaRepository.update(deleted.copy(bookId = bookToAdd.id))
-            }
+            mediaRepository.copy(match.id, bookToAdd.id)
 
             // copy generated and user uploaded thumbnails
             thumbnailBookRepository.findAllByBookIdAndType(match.id, setOf(ThumbnailBook.Type.GENERATED, ThumbnailBook.Type.USER_UPLOADED)).forEach { deleted ->
diff --git a/komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/main/MediaDao.kt b/komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/main/MediaDao.kt
index 69339dad..e5f7375c 100644
--- a/komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/main/MediaDao.kt
+++ b/komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/main/MediaDao.kt
@@ -1,6 +1,7 @@
 package org.gotson.komga.infrastructure.jooq.main
 
 import com.fasterxml.jackson.databind.ObjectMapper
+import io.github.oshai.kotlinlogging.KotlinLogging
 import org.gotson.komga.domain.model.BookPage
 import org.gotson.komga.domain.model.Dimension
 import org.gotson.komga.domain.model.Media
@@ -26,6 +27,8 @@ import org.springframework.transaction.annotation.Transactional
 import java.time.LocalDateTime
 import java.time.ZoneId
 
+private val logger = KotlinLogging.logger {}
+
 @Component
 class MediaDao(
   dslRW: DSLContext,
@@ -158,7 +161,14 @@ class MediaDao(
                 media.pageCount,
                 media.epubDivinaCompatible,
                 media.epubIsKepub,
-                media.extension?.let { if (it is ProxyExtension) null else it::class.qualifiedName },
+                media.extension?.let {
+                  if (it is ProxyExtension) {
+                    logger.error { "Found ProxyExtension while trying to insert Media: this is not expected and should be reported." }
+                    null
+                  } else {
+                    it::class.qualifiedName
+                  }
+                },
                 media.extension?.let { if (it is ProxyExtension) null else mapper.serializeJsonGz(it) },
               )
             }
@@ -249,9 +259,13 @@ class MediaDao(
       .set(m.EPUB_DIVINA_COMPATIBLE, media.epubDivinaCompatible)
       .set(m.EPUB_IS_KEPUB, media.epubIsKepub)
       .apply {
-        if (media.extension != null && media.extension !is ProxyExtension) {
-          set(m.EXTENSION_CLASS, media.extension::class.qualifiedName)
-          set(m.EXTENSION_VALUE_BLOB, mapper.serializeJsonGz(media.extension))
+        if (media.extension != null) {
+          if (media.extension !is ProxyExtension) {
+            set(m.EXTENSION_CLASS, media.extension::class.qualifiedName)
+            set(m.EXTENSION_VALUE_BLOB, mapper.serializeJsonGz(media.extension))
+          } else {
+            logger.error { "Found ProxyExtension while trying to update Media: this is not expected and should be reported." }
+          }
         }
       }.set(m.LAST_MODIFIED_DATE, LocalDateTime.now(ZoneId.of("Z")))
       .where(m.BOOK_ID.eq(media.bookId))
@@ -271,6 +285,18 @@ class MediaDao(
     dslRW.insertFiles(listOf(media))
   }
 
+  @Transactional
+  override fun copy(
+    fromBookId: String,
+    toBookId: String,
+  ) {
+    val source = findById(fromBookId)
+    val sourceExtension = findExtensionByIdOrNull(fromBookId)
+
+    val copy = source.copy(bookId = toBookId, extension = sourceExtension)
+    update(copy)
+  }
+
   @Transactional
   override fun delete(bookId: String) {
     dslRW.deleteFrom(p).where(p.BOOK_ID.eq(bookId)).execute()