Avoid attempts to renaming download dirs if name hasn't actually changed

Maybe fixes #9503

(cherry picked from commit fb38d307750a849e7c941c164a3c223d69f2cd14)

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

@@ -358,9 +358,11 @@ class DownloadManager(
         val oldFolder = provider.findSourceDir(oldSource) ?: return
         val newName = provider.getSourceDirName(newSource)
 
+        if (oldFolder.name == newName) return
+
         val capitalizationChanged = oldFolder.name.equals(newName, ignoreCase = true)
         if (capitalizationChanged) {
-            val tempName = newName + "_tmp"
+            val tempName = newName + Downloader.TMP_DIR_SUFFIX
             if (oldFolder.renameTo(tempName).not()) {
                 logcat(LogPriority.ERROR) { "Failed to rename source download folder: ${oldFolder.name}" }
                 return
@@ -394,6 +396,8 @@ class DownloadManager(
             newName += ".cbz"
         }
 
+        if (oldDownload.name == newName) return
+
         if (oldDownload.renameTo(newName)) {
             cache.removeChapter(oldChapter, manga)
             cache.addChapter(newName, mangaDir, manga)

app/src/main/java/eu/kanade/tachiyomi/source/AndroidSourceManager.kt

@@ -209,7 +209,7 @@ class AndroidSourceManager(
             registerStubSource(it)
             return it
         }
-        return StubSource(id, "", "")
+        return StubSource(id = id, lang = "", name = "")
     }
 
     // SY -->