From 519101a8a48374d001a489c0f6350f0e83969f24 Mon Sep 17 00:00:00 2001
From: Hans-Christoph Steiner <hans@eds.org>
Date: Wed, 27 Jun 2018 14:16:15 +0200
Subject: [PATCH] prevent crash loop after rapid install/uninstall cycling
If you quickly cycle between installing an app and uninstalling it, then
`app.installedApk` will still be null when AppDetails2.startUninstall()
calls InstallerService.uninstall(). It is better to crash earlier here,
before the Intent is sent with a null APK, because InstallerService is set
to receive Sticky Intents. That means they will automatically be resent
by the system until they successfully complete.
---
.../fdroid/installer/InstallerService.java | 27 ++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java b/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java
index 140665c58..db214122b 100644
--- a/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java
+++ b/app/src/main/java/org/fdroid/fdroid/installer/InstallerService.java
@@ -32,6 +32,7 @@ import org.fdroid.fdroid.data.Apk;
import java.io.File;
import java.io.FileFilter;
+import java.util.Objects;
/**
* This service handles the install process of apk files and
@@ -63,6 +64,9 @@ public class InstallerService extends JobIntentService {
@Override
protected void onHandleWork(@NonNull Intent intent) {
final Apk apk = intent.getParcelableExtra(Installer.EXTRA_APK);
+ if (apk == null) {
+ return;
+ }
Installer installer = InstallerFactory.create(this, apk);
if (ACTION_INSTALL.equals(intent.getAction())) {
@@ -98,12 +102,17 @@ public class InstallerService extends JobIntentService {
}
/**
- * Install an apk from {@link Uri}
+ * Install an apk from {@link Uri}.
+ * <p>
+ * This does not include the same level of input validation as
+ * {@link #uninstall(Context, Apk)} since this is called in one place where
+ * the input has already been validated.
*
* @param context this app's {@link Context}
* @param localApkUri {@link Uri} pointing to (downloaded) local apk file
* @param downloadUri {@link Uri} where the apk has been downloaded from
* @param apk apk object of app that should be installed
+ * @see #uninstall(Context, Apk)
*/
public static void install(Context context, Uri localApkUri, Uri downloadUri, Apk apk) {
Intent intent = new Intent(context, InstallerService.class);
@@ -115,12 +124,24 @@ public class InstallerService extends JobIntentService {
}
/**
- * Uninstall an app
+ * Uninstall an app. {@link Objects#requireNonNull(Object)} is used to
+ * enforce the {@code @NonNull} requirement, since that annotation alone
+ * is not enough to catch all possible nulls.
+ * <p>
+ * If you quickly cycle between installing an app and uninstalling it, then
+ * {@link org.fdroid.fdroid.data.App#installedApk} will still be null when
+ * {@link org.fdroid.fdroid.AppDetails2#startUninstall()} calls
+ * this method. It is better to crash earlier here, before the {@link Intent}
+ * is sent with a null {@link Apk} instance since this service is set to
+ * receive Sticky Intents. That means they will automatically be resent
+ * by the system until they successfully complete. If an {@code Intent}
+ * with a null {@code Apk} is sent, it'll crash.
*
* @param context this app's {@link Context}
* @param apk {@link Apk} instance of the app that will be uninstalled
*/
- public static void uninstall(Context context, Apk apk) {
+ public static void uninstall(Context context, @NonNull Apk apk) {
+ Objects.requireNonNull(apk);
Intent intent = new Intent(context, InstallerService.class);
intent.setAction(ACTION_UNINSTALL);
intent.putExtra(Installer.EXTRA_APK, apk);