Maintain source info in the database. (#6389)

* Maintain Source Info in database

* Review changes and cleanups

* Review changes 2

* Review Changes 3

app/src/main/java/eu/kanade/tachiyomi/data/backup/full/FullBackupRestoreValidator.kt

@@ -43,7 +43,12 @@ class FullBackupRestoreValidator : AbstractBackupRestoreValidator() {
         val sources = backup.backupSources.associate { it.sourceId to it.name }
         val missingSources = sources
             .filter { sourceManager.get(it.key) == null }
-            .values
+            .values.map {
+                val id = it.toLongOrNull()
+                if (id == null) it
+                else sourceManager.getOrStub(id).toString()
+            }
+            .distinct()
             .sorted()
 
         val trackers = backup.backupManga

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt

@@ -71,7 +71,7 @@ class DownloadCache(
      */
     fun isChapterDownloaded(chapter: Chapter, manga: Manga, skipCache: Boolean): Boolean {
         if (skipCache) {
-            val source = sourceManager.get(manga.source) ?: return false
+            val source = sourceManager.getOrStub(manga.source)
             return provider.findChapterDir(chapter, manga, source) != null
         }
 
@@ -124,11 +124,15 @@ class DownloadCache(
     private fun renew() {
         val onlineSources = sourceManager.getOnlineSources()
 
+        val stubSources = sourceManager.getStubSources()
+
+        val allSource = onlineSources + stubSources
+
         val sourceDirs = rootDir.dir.listFiles()
             .orEmpty()
             .associate { it.name to SourceDirectory(it) }
             .mapNotNullKeys { entry ->
-                onlineSources.find { provider.getSourceDirName(it).equals(entry.key, ignoreCase = true) }?.id
+                allSource.find { provider.getSourceDirName(it).equals(entry.key, ignoreCase = true) }?.id
             }
 
         rootDir.files = sourceDirs