Properly handle PACKAGE_REPLACED in addition to _ADDED and _REMOVED

Certain kinds of application update generate this broadcast regime rather
than the REMOVE / ADD sequence that results from e.g. using the -r option
when invoking 'adb install'.

We also push the agent classname lookup to the last moment before
actually running the backup, rather than caching it as part of the
record of what apps need a backup pass in the future.  This was causing
a bug in which a package reinstall that renamed the app's agent class
would wind up with a crash at backup time, trying to load the wrong
class.

Fixes bug 5156094 / bug 4308977

Change-Id: I4e3e12d86e6ee40809f14fd12ab762116dbee0b5

Author: Christopher Tate

services/java/com/android/server/BackupManagerService.java

@@ -197,14 +197,14 @@ class BackupManagerService extends IBackupManager.Stub {
         = new SparseArray<HashSet<ApplicationInfo>>();
     // set of backup services that have pending changes
     class BackupRequest {
-        public ApplicationInfo appInfo;
+        public String packageName;
 
-        BackupRequest(ApplicationInfo app) {
-            appInfo = app;
+        BackupRequest(String pkgName) {
+            packageName = pkgName;
         }
 
         public String toString() {
-            return "BackupRequest{app=" + appInfo + "}";
+            return "BackupRequest{pkg=" + packageName + "}";
         }
     }
     // Backups that we haven't started yet.  Keys are package names.
@@ -877,6 +877,7 @@ private void initPackageTracking() {
         IntentFilter filter = new IntentFilter();
         filter.addAction(Intent.ACTION_PACKAGE_ADDED);
         filter.addAction(Intent.ACTION_PACKAGE_REMOVED);
+        filter.addAction(Intent.ACTION_PACKAGE_REPLACED);
         filter.addDataScheme("package");
         mContext.registerReceiver(mBroadcastReceiver, filter);
         // Register for events related to sdcard installation.
@@ -1174,7 +1175,8 @@ public void onReceive(Context context, Intent intent) {
             Bundle extras = intent.getExtras();
             String pkgList[] = null;
             if (Intent.ACTION_PACKAGE_ADDED.equals(action) ||
-                    Intent.ACTION_PACKAGE_REMOVED.equals(action)) {
+                    Intent.ACTION_PACKAGE_REMOVED.equals(action) ||
+                    Intent.ACTION_PACKAGE_REPLACED.equals(action)) {
                 Uri uri = intent.getData();
                 if (uri == null) {
                     return;
@@ -1183,15 +1185,22 @@ public void onReceive(Context context, Intent intent) {
                 if (pkgName != null) {
                     pkgList = new String[] { pkgName };
                 }
-                added = Intent.ACTION_PACKAGE_ADDED.equals(action);
-                replacing = extras.getBoolean(Intent.EXTRA_REPLACING, false);
+                if (Intent.ACTION_PACKAGE_REPLACED.equals(action)) {
+                    // use the existing "add with replacement" logic
+                    if (MORE_DEBUG) Slog.d(TAG, "PACKAGE_REPLACED, updating package " + pkgName);
+                    added = replacing = true;
+                } else {
+                    added = Intent.ACTION_PACKAGE_ADDED.equals(action);
+                    replacing = extras.getBoolean(Intent.EXTRA_REPLACING, false);
+                }
             } else if (Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE.equals(action)) {
                 added = true;
                 pkgList = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
             } else if (Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE.equals(action)) {
                 added = false;
                 pkgList = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
             }
+
             if (pkgList == null || pkgList.length == 0) {
                 return;
             }
@@ -1665,9 +1674,7 @@ public void run() {
                 if (status == BackupConstants.TRANSPORT_OK) {
                     PackageManagerBackupAgent pmAgent = new PackageManagerBackupAgent(
                             mPackageManager, allAgentPackages());
-                    BackupRequest pmRequest = new BackupRequest(new ApplicationInfo());
-                    pmRequest.appInfo.packageName = PACKAGE_MANAGER_SENTINEL;
-                    status = processOneBackup(pmRequest,
+                    status = processOneBackup(PACKAGE_MANAGER_SENTINEL,
                             IBackupAgent.Stub.asInterface(pmAgent.onBind()), mTransport);
                 }
 
@@ -1716,7 +1723,7 @@ public void run() {
                 if (status != BackupConstants.TRANSPORT_OK) {
                     Slog.w(TAG, "Backup pass unsuccessful, restaging");
                     for (BackupRequest req : mQueue) {
-                        dataChangedImpl(req.appInfo.packageName);
+                        dataChangedImpl(req.packageName);
                     }
 
                     // We also want to reset the backup schedule based on whatever
@@ -1750,29 +1757,31 @@ private int doQueuedBackups(IBackupTransport transport) {
                 // Verify that the requested app exists; it might be something that
                 // requested a backup but was then uninstalled.  The request was
                 // journalled and rather than tamper with the journal it's safer
-                // to sanity-check here.
+                // to sanity-check here.  This also gives us the classname of the
+                // package's backup agent.
+                PackageInfo pkg;
                 try {
-                    mPackageManager.getPackageInfo(request.appInfo.packageName, 0);
+                    pkg = mPackageManager.getPackageInfo(request.packageName, 0);
                 } catch (NameNotFoundException e) {
                     Slog.d(TAG, "Package does not exist; skipping");
                     continue;
                 }
 
                 IBackupAgent agent = null;
                 try {
-                    mWakelock.setWorkSource(new WorkSource(request.appInfo.uid));
-                    agent = bindToAgentSynchronous(request.appInfo,
+                    mWakelock.setWorkSource(new WorkSource(pkg.applicationInfo.uid));
+                    agent = bindToAgentSynchronous(pkg.applicationInfo,
                             IApplicationThread.BACKUP_MODE_INCREMENTAL);
                     if (agent != null) {
-                        int result = processOneBackup(request, agent, transport);
+                        int result = processOneBackup(request.packageName, agent, transport);
                         if (result != BackupConstants.TRANSPORT_OK) return result;
                     }
                 } catch (SecurityException ex) {
                     // Try for the next one.
                     Slog.d(TAG, "error in bind/backup", ex);
                 } finally {
                     try {  // unbind even on timeout, just in case
-                        mActivityManager.unbindBackupAgent(request.appInfo);
+                        mActivityManager.unbindBackupAgent(pkg.applicationInfo);
                     } catch (RemoteException e) {}
                 }
             }
@@ -1782,9 +1791,8 @@ private int doQueuedBackups(IBackupTransport transport) {
             return BackupConstants.TRANSPORT_OK;
         }
 
-        private int processOneBackup(BackupRequest request, IBackupAgent agent,
+        private int processOneBackup(String packageName, IBackupAgent agent,
                 IBackupTransport transport) {
-            final String packageName = request.appInfo.packageName;
             if (DEBUG) Slog.d(TAG, "processOneBackup doBackup() on " + packageName);
 
             File savedStateName = new File(mStateDir, packageName);
@@ -4207,7 +4215,7 @@ private void dataChangedImpl(String packageName, HashSet<ApplicationInfo> target
                 if (app.packageName.equals(packageName)) {
                     // Add the caller to the set of pending backups.  If there is
                     // one already there, then overwrite it, but no harm done.
-                    BackupRequest req = new BackupRequest(app);
+                    BackupRequest req = new BackupRequest(packageName);
                     if (mPendingBackups.put(app.packageName, req) == null) {
                         // Journal this request in case of crash.  The put()
                         // operation returned null when this package was not already
@@ -4218,7 +4226,7 @@ private void dataChangedImpl(String packageName, HashSet<ApplicationInfo> target
                             int numKeys = mPendingBackups.size();
                             Slog.d(TAG, "Now awaiting backup for " + numKeys + " participants:");
                             for (BackupRequest b : mPendingBackups.values()) {
-                                Slog.d(TAG, "    + " + b + " agent=" + b.appInfo.backupAgentName);
+                                Slog.d(TAG, "    + " + b);
                             }
                         }
                     }