Watch out for deleted user when exiting async task

Fixes a problem where the async task can take a while to execute
and in the meantime the user can be removed. On exiting the async
task and updating the UI, make sure the user hasn't been deleted.

Bug: 18411181
Change-Id: I1831f3e53084c49e27557cb7aacec78c753a611b

src/com/android/settings/Utils.java

@@ -1023,4 +1023,21 @@ public final class Utils {
         return null;
     }
 
+    /**
+     * Queries for the UserInfo of a user. Returns null if the user doesn't exist (was removed).
+     * @param userManager Instance of UserManager
+     * @param checkUser The user to check the existence of.
+     * @return UserInfo of the user or null for non-existent user.
+     */
+    public static UserInfo getExistingUser(UserManager userManager, UserHandle checkUser) {
+        final List<UserInfo> users = userManager.getUsers(true /* excludeDying */);
+        final int checkUserId = checkUser.getIdentifier();
+        for (UserInfo user : users) {
+            if (user.id == checkUserId) {
+                return user;
+            }
+        }
+        return null;
+    }
+
 }

src/com/android/settings/users/AppRestrictionsFragment.java

@@ -58,6 +58,7 @@ import android.widget.Switch;
 
 import com.android.settings.R;
 import com.android.settings.SettingsPreferenceFragment;
+import com.android.settings.Utils;
 import com.android.settings.drawable.CircleFramedDrawable;
 
 import java.util.ArrayList;
@@ -643,12 +644,16 @@ public class AppRestrictionsFragment extends SettingsPreferenceFragment implemen
         if (context == null) return;
         final PackageManager pm = mPackageManager;
         final IPackageManager ipm = mIPm;
+        final int userId = mUser.getIdentifier();
 
+        // Check if the user was removed in the meantime.
+        if (Utils.getExistingUser(mUserManager, mUser) == null) {
+            return;
+        }
         mAppList.removeAll();
         Intent restrictionsIntent = new Intent(Intent.ACTION_GET_RESTRICTION_ENTRIES);
         final List<ResolveInfo> receivers = pm.queryBroadcastReceivers(restrictionsIntent, 0);
         int i = 0;
-        if (mVisibleApps.size() > 0) {
         for (SelectableAppInfo app : mVisibleApps) {
             String packageName = app.packageName;
             if (packageName == null) continue;
@@ -671,10 +676,13 @@ public class AppRestrictionsFragment extends SettingsPreferenceFragment implemen
             try {
                 pi = ipm.getPackageInfo(packageName,
                         PackageManager.GET_UNINSTALLED_PACKAGES
-                            | PackageManager.GET_SIGNATURES, mUser.getIdentifier());
+                        | PackageManager.GET_SIGNATURES, userId);
             } catch (RemoteException e) {
             }
-                if (pi != null && (pi.requiredForAllUsers || isPlatformSigned(pi))) {
+            if (pi == null) {
+                continue;
+            }
+            if (pi.requiredForAllUsers || isPlatformSigned(pi)) {
                 p.setChecked(true);
                 p.setImmutable(true);
                 // If the app is required and has no restrictions, skip showing it
@@ -712,7 +720,6 @@ public class AppRestrictionsFragment extends SettingsPreferenceFragment implemen
             mAppListChanged = true;
             i++;
         }
-        }
         // If this is the first time for a new profile, install/uninstall default apps for profile
         // to avoid taking the hit in onPause(), which can cause race conditions on user switch.
         if (mNewUser && mFirstTime) {

src/com/android/settings/users/RestrictedProfileSettings.java

@@ -87,7 +87,7 @@ public class RestrictedProfileSettings extends AppRestrictionsFragment
         super.onResume();
 
         // Check if user still exists
-        UserInfo info = getExistingUser(mUser);
+        UserInfo info = Utils.getExistingUser(mUserManager, mUser);
         if (info == null) {
             finishFragment();
         } else {
@@ -97,16 +97,6 @@ public class RestrictedProfileSettings extends AppRestrictionsFragment
         }
     }
 
-    private UserInfo getExistingUser(UserHandle thisUser) {
-        final List<UserInfo> users = mUserManager.getUsers(true); // Only get non-dying
-        for (UserInfo user : users) {
-            if (user.id == thisUser.getIdentifier()) {
-                return user;
-            }
-        }
-        return null;
-    }
-
     @Override
     public void startActivityForResult(Intent intent, int requestCode) {
         mEditUserInfoController.startingActivityForResult();