subscriptionResult.getPurchasesList() may return null to cause NPE

Thanks for the great project!

I used it in my App PureWriter and got a NullPointerException related to the BillingManager(line: 316):

https://github.com/googlesamples/android-play-billing/blob/3493967b5d7f54861efbfc1038d21d820077942b/TrivialDrive_v2/shared-module/src/main/java/com/example/billingmodule/billing/BillingManager.java#L314-L316

and

https://github.com/googlesamples/android-play-billing/blob/3493967b5d7f54861efbfc1038d21d820077942b/TrivialDrive_v2/shared-module/src/main/java/com/example/billingmodule/billing/BillingManager.java#L319-L320

[ghost]

I have similar the problem with the billing libray 1.2 purchasesResult.purchasesList always return null. I can’t check if a user paid to restore paid state. I need to make a new purchase and check if reponseCode return ITEM_ALREADY_OWNED

billingClient = BillingClient.newBuilder(activity).setListener(this).build()
val purchasesResult = billingClient.queryPurchases(INAPP)
Timber.d("purchasesResult.responseCode -> ${purchasesResult.responseCode}")
if (purchasesResult.responseCode == OK && purchasesResult.purchasesList != null) {
      // never call even responseCode == OK
	purchasesResult.purchasesList.forEach {
		Timber.d("purchased item -> ${it.sku} - ${it.orderId}")
	}
	donateClientListener.markPurchased()
}

---------------------------------------------

fun makePurchase(skuDetails: SkuDetails): Boolean {
	val flowParams = BillingFlowParams.newBuilder()
			.setSkuDetails(skuDetails)
			.build()
	val responseCode = billingClient.launchBillingFlow(activity, flowParams)
	when (responseCode) {
		ITEM_ALREADY_OWNED -> donateClientListener.markPurchased() // user paid

		OK -> Timber.d("makePurchase() successful!")

		else -> Timber.e(DonationException("makePurchase()", responseCode))
	}

	billingClient.endConnection()

	return responseCode == OK
}

[mediavrog]

Oh and for the size issue, this is definitely a sample error since without checking the response code for OK, the logging logs

Log.i(TAG, "Querying subscriptions result code: "
                        + subscriptionResult.responseCode
                        + " res: ${subscriptionResult.purchasesList.size}")

At least for Kotlin, it should be

Log.i(TAG, "Querying subscriptions result code: "
                        + subscriptionResult.responseCode
                        + " res: ${subscriptionResult.purchasesList?.size}")

This bug will not surface if your proguard strips all logs in production