Make it possible to remove current user

Due to the async nature of switching users, it's not possible to
switch and remove immediately. So mark the switch target user as
soon as the user switch is requested, so that a remove will proceed
without failing at stopUserLocked().

Also, fix a similar problem with deleting the current guest and
switching to a new guest. It was attempting to remove the current
user which will result in a failed stopping of the user.
Added a way to mark the current guest
for deletion so that a new one can be created, switched to and the
old one deleted. If runtime fails, old guest is already marked for
deletion and will be cleaned up on restart.

Bug: 17321533
Change-Id: I4be0fb956227e0bb95588b5b1f2867fb1e655c0d

2 files changed, 17 insertions, 0 deletions

diff --git a/core/java/android/os/IUserManager.aidl b/core/java/android/os/IUserManager.aidl
index 713fcd8..3286627 100644
--- a/core/java/android/os/IUserManager.aidl
+++ b/core/java/android/os/IUserManager.aidl
@@ -52,4 +52,5 @@ interface IUserManager {
     void removeRestrictions();
     void setDefaultGuestRestrictions(in Bundle restrictions);
     Bundle getDefaultGuestRestrictions();
+    boolean markGuestForDeletion(int userHandle);
 }
diff --git a/core/java/android/os/UserManager.java b/core/java/android/os/UserManager.java
index e215669..f793667 100644
--- a/core/java/android/os/UserManager.java
+++ b/core/java/android/os/UserManager.java
@@ -676,6 +676,22 @@ public class UserManager {
     }
 
     /**
+     * @hide
+     * Marks the guest user for deletion to allow a new guest to be created before deleting
+     * the current user who is a guest.
+     * @param userHandle
+     * @return
+     */
+    public boolean markGuestForDeletion(int userHandle) {
+        try {
+            return mService.markGuestForDeletion(userHandle);
+        } catch (RemoteException re) {
+            Log.w(TAG, "Could not mark guest for deletion", re);
+            return false;
+        }
+    }
+
+    /**
      * Sets the user as enabled, if such an user exists.
      * Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
      * Note that the default is true, it's only that managed profiles might not be enabled.