BrowserAuthorizationFragment.createCustomTabResponseIntent crash NullPointerException

Describe the bug My app is live and got this bug when use start sign in, the bug was reported in Firebase Crashlystic

Smartphone (please complete the following information):

• Device: Xperia X
• Android Version: 8.0.0
• Browser: don’t know
• MSAL Version: 1.4.0

Stacktrace

Caused by java.lang.NullPointerException
Attempt to invoke virtual method 'java.lang.String java.lang.Class.getName()' on a null object reference
android.content.ComponentName.<init> (ComponentName.java:131)
android.content.Intent.<init> (Intent.java:5698)
com.microsoft.identity.common.internal.providers.oauth2.BrowserAuthorizationFragment.createCustomTabResponseIntent (BrowserAuthorizationFragment.java:77)
com.microsoft.identity.client.BrowserTabActivity.onCreate (BrowserTabActivity.java:64)
android.app.Activity.performCreate (Activity.java:6975)
android.app.Instrumentation.callActivityOnCreate (Instrumentation.java:1214)
android.app.ActivityThread.performLaunchActivity (ActivityThread.java:2778)
android.app.ActivityThread.handleLaunchActivity (ActivityThread.java:2900)
android.app.ActivityThread.-wrap11 (ActivityThread.java)
android.app.ActivityThread$H.handleMessage (ActivityThread.java:1601)
android.os.Handler.dispatchMessage (Handler.java:105)
android.os.Looper.loop (Looper.java:251)
android.app.ActivityThread.main (ActivityThread.java:6589)
java.lang.reflect.Method.invoke (Method.java)
com.android.internal.os.Zygote$MethodAndArgsCaller.run (Zygote.java:240)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:767)

To Reproduce

• Start user authentication screen

Expected behavior User can signed in

Actual Behavior Crash because of this error

Additional context This bug is a random crash. Not all users have it. I checked the code where it crashes, the sCallingActivityClass static field was null that was used before it is set by BrowserAuthorizationFragment.createCustomTabResponseIntent(..)

[pomian17]

@shahzaibj, we are also facing this bug. There are some devices (e.g. Xiaomi Mi A2 lite, Huawei P10 lite, LG K4, Polaroid Snap S60, LG X power) that this happens on (no specific Android version, seems to happen on all of them) Scenario is as follows:

1. Open Login/forgot/password/register page (in BrowserAuthorizationFragment)
2. Activity gets killed by system, only browser window remains.
3. Fill in the forms. Click e.g. login to return to app.
4. Activity is recreated, but it has no preserved state, so before app crashed due to NullPointerException, now it shows toast, but it does not change the fact, that user is not able to be authorized.

It does not happens always, but usually there has to be about 3-4 bug occurences until user is able to proceed. Maybe there is a way to make this activity able to survive process death?

Also, changing authorization_user_agent setting to WEBVIEW helps, as mentioned in https://github.com/AzureAD/microsoft-authentication-library-for-android/issues/923, but we still have problem in register form, where after clicking privacy policy link, and coming back, activity is restarted. User cannot also change app to other during this process. For example to get code that was sent to email and has to be provided in app. After coming back, registration process is restarted.

[shahzaibj]

@andj207 We’ve fixed this in MSAL v1.5.0 https://github.com/AzureAD/microsoft-authentication-library-for-android/releases/tag/v1.5.0