Fixed crash after repeated rotation.

Author: isayan

android_app/app/build.gradle

@@ -13,7 +13,7 @@ android {
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
         externalNativeBuild {
             cmake {
-                cppFlags "-std=c++11 -fvisibility=hidden "
+                cppFlags "-std=c++17 -fvisibility=hidden "
                 abiFilters 'armeabi-v7a','arm64-v8a', 'x86'
                 arguments "-DCMAKE_VERBOSE_MAKEFILE=1 -DANDROID_FUNCTION_LEVEL_LINKING=ON"
             }

android_app/app/src/main/java/tun/proxy/SettingsActivity.java

@@ -270,7 +270,9 @@ protected void filter(String filter, final MyApplication.AppSortBy sortBy, final
 
             this.removeAllPreferenceScreen();
             //final AsyncTaskProgress task = new AsyncTaskProgress(this);
-            task.execute();
+            if (task.getStatus() == AsyncTask.Status.PENDING) {
+                task.execute();
+            }
 //            this.filterPackagesPreferences(filter, sortBy, orderBy);
         }
 
@@ -574,6 +576,8 @@ protected void onPostExecute(List<PackageInfo> installedPackages) {
         @Override
         protected void onCancelled() {
             super.onCancelled();
+            packageFragment.mAllPackageInfoMap.clear();
+            packageFragment.mFilterPreferenceScreen.removeAll();
             return;
         }
 

android_app/build.gradle

@@ -8,7 +8,7 @@ buildscript {
 
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.1'
+        classpath 'com.android.tools.build:gradle:3.6.2'
 
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files