Confirm exit for migrations

(cherry picked from commit 640bd8d9babb3ace1d6a370adad35050271aa008)

app/src/main/java/eu/kanade/tachiyomi/ui/migration/manga/process/MigrationListController.kt

@@ -130,6 +130,13 @@ class MigrationListController(bundle: Bundle? = null) : BaseController(bundle),
             sourceManager.get(value) as? CatalogueSource }
         if (config == null) return
         for (manga in mangas) {
+            if (migrationsJob?.isCancelled == true) {
+                break
+            }
+            // in case it was removed
+            if (manga.mangaId !in config.mangaIds) {
+                continue
+            }
             if (!manga.searchResult.initialized && manga.migrationJob.isActive) {
                 val mangaObj = manga.manga()
 
@@ -246,7 +253,9 @@ class MigrationListController(bundle: Bundle? = null) : BaseController(bundle),
 
     override fun updateCount() {
         launchUI {
-            setTitle()
+            if (router.backstack.last().controller() == this@MigrationListController) {
+                setTitle()
+            }
         }
     }
 
@@ -370,6 +379,24 @@ class MigrationListController(bundle: Bundle? = null) : BaseController(bundle),
         }
     }
 
+    override fun handleBack(): Boolean {
+        activity?.let {
+            MaterialDialog.Builder(it).title(R.string.stop_migration)
+                .positiveText(R.string.yes)
+                .negativeText(R.string.no)
+                .onPositive { _, _ ->
+                    router.popCurrentController()
+                    migrationsJob?.cancel()
+                }
+                .show()
+        }
+        return true
+    }
+
+    override fun onDestroyView(view: View) {
+        super.onDestroyView(view)
+    }
+
     override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
         inflater.inflate(R.menu.migration_list, menu)
     }

app/src/main/res/values/strings.xml

@@ -493,9 +493,11 @@
     <string name="skipping_x">(skipping %1$d)</string>
     <string name="x_migrations">%1$s manga migrated</string>
     <string name="no">No</string>
+    <string name="yes">Yes</string>
     <string name="error_fetching_migration">No chapters found, this manga cannot be used for
         migration</string>
     <string name="no_alternatives_found">No Alternatives Found</string>
+    <string name="stop_migration">Stop migrating?</string>
 
     <!-- Tracking Screen -->
     <string name="manga_tracking_tab">Tracking</string>