From 942101d7e253669ad232a9556304d6e1ff07f9bd Mon Sep 17 00:00:00 2001
From: Stas Parshin <s.a.parshin@gmail.com>
Date: Wed, 21 Dec 2016 15:06:28 +0700
Subject: [PATCH] Fix Context leak in LatestAppVersion task, #64, #66

---
 .../javiersantos/appupdater/AppUpdater.java   |  5 +++
 .../javiersantos/appupdater/UtilsAsync.java   | 43 +++++++++++++------
 2 files changed, 36 insertions(+), 12 deletions(-)

diff --git a/library/src/main/java/com/github/javiersantos/appupdater/AppUpdater.java b/library/src/main/java/com/github/javiersantos/appupdater/AppUpdater.java
index 0c0261b8..ed963a53 100644
--- a/library/src/main/java/com/github/javiersantos/appupdater/AppUpdater.java
+++ b/library/src/main/java/com/github/javiersantos/appupdater/AppUpdater.java
@@ -1,5 +1,6 @@
 package com.github.javiersantos.appupdater;
 
+import android.app.Activity;
 import android.content.Context;
 import android.support.annotation.DrawableRes;
 import android.support.annotation.NonNull;
@@ -300,6 +301,10 @@ public void start() {
         latestAppVersion = new UtilsAsync.LatestAppVersion(context, false, updateFrom, gitHub, xmlOrJsonUrl, new LibraryListener() {
             @Override
             public void onSuccess(Update update) {
+                if (context instanceof Activity && ((Activity) context).isFinishing()) {
+                    return;
+                }
+
                 if (UtilsLibrary.isUpdateAvailable(UtilsLibrary.getAppInstalledVersion(context), update.getLatestVersion())) {
                     Integer successfulChecks = libraryPreferences.getSuccessfulChecks();
                     if (UtilsLibrary.isAbleToShow(successfulChecks, showEvery)) {
diff --git a/library/src/main/java/com/github/javiersantos/appupdater/UtilsAsync.java b/library/src/main/java/com/github/javiersantos/appupdater/UtilsAsync.java
index e9a4e453..68ec0901 100644
--- a/library/src/main/java/com/github/javiersantos/appupdater/UtilsAsync.java
+++ b/library/src/main/java/com/github/javiersantos/appupdater/UtilsAsync.java
@@ -8,32 +8,38 @@
 import com.github.javiersantos.appupdater.objects.GitHub;
 import com.github.javiersantos.appupdater.objects.Update;
 
+import java.lang.ref.WeakReference;
+
 class UtilsAsync {
 
     static class LatestAppVersion extends AsyncTask<Void, Void, Update> {
-        private Context context;
+        private WeakReference<Context> contextRef;
         private LibraryPreferences libraryPreferences;
         private Boolean fromUtils;
         private UpdateFrom updateFrom;
         private GitHub gitHub;
         private String xmlOrJsonUrl;
-        private AppUpdater.LibraryListener listener;
+        private WeakReference<AppUpdater.LibraryListener> listenerRef;
 
         public LatestAppVersion(Context context, Boolean fromUtils, UpdateFrom updateFrom, GitHub gitHub, String xmlOrJsonUrl, AppUpdater.LibraryListener listener) {
-            this.context = context;
+            this.contextRef = new WeakReference<>(context);
             this.libraryPreferences = new LibraryPreferences(context);
             this.fromUtils = fromUtils;
             this.updateFrom = updateFrom;
             this.gitHub = gitHub;
             this.xmlOrJsonUrl = xmlOrJsonUrl;
-            this.listener = listener;
+            this.listenerRef = new WeakReference<>(listener);
         }
 
         @Override
         protected void onPreExecute() {
             super.onPreExecute();
 
-            if (UtilsLibrary.isNetworkAvailable(context)) {
+            Context context = contextRef.get();
+            AppUpdater.LibraryListener listener = listenerRef.get();
+            if (context == null || listener == null) {
+                cancel(true);
+            } else if (UtilsLibrary.isNetworkAvailable(context)) {
                 if (!fromUtils && !libraryPreferences.getAppUpdaterShow()) {
                     cancel(true);
                 } else {
@@ -60,28 +66,41 @@ protected void onPreExecute() {
         protected Update doInBackground(Void... voids) {
             if (updateFrom == UpdateFrom.XML || updateFrom == UpdateFrom.JSON) {
                 Update update = UtilsLibrary.getLatestAppVersion(updateFrom, xmlOrJsonUrl);
-                    if (update != null) {
+                if (update != null) {
                     return update;
                 } else {
                     AppUpdaterError error = updateFrom == UpdateFrom.XML ? AppUpdaterError.XML_ERROR
                             : AppUpdaterError.JSON_ERROR;
 
-                    listener.onFailed(error);
+                    AppUpdater.LibraryListener listener = listenerRef.get();
+                    if (listener != null) {
+                        listener.onFailed(error);
+                    }
                     cancel(true);
                     return null;
                 }
             } else {
-                return UtilsLibrary.getLatestAppVersionHttp(context, updateFrom, gitHub);
+                Context context = contextRef.get();
+                if (context != null) {
+                    return UtilsLibrary.getLatestAppVersionHttp(context, updateFrom, gitHub);
+                } else {
+                    cancel(true);
+                    return null;
+                }
             }
         }
 
         @Override
         protected void onPostExecute(Update update) {
             super.onPostExecute(update);
-            if (UtilsLibrary.isStringAVersion(update.getLatestVersion())) {
-                listener.onSuccess(update);
-            } else {
-                listener.onFailed(AppUpdaterError.UPDATE_VARIES_BY_DEVICE);
+
+            AppUpdater.LibraryListener listener = listenerRef.get();
+            if (listener != null) {
+                if (UtilsLibrary.isStringAVersion(update.getLatestVersion())) {
+                    listener.onSuccess(update);
+                } else {
+                    listener.onFailed(AppUpdaterError.UPDATE_VARIES_BY_DEVICE);
+                }
             }
         }
     }