PreviewChannelHelper.updatePreviewChannel throws NullPointerException when trying to update a channel that has no description [119800858]

Fixed

Bug

[AOSP] assigned

Status Update

No update yet.

Description

cl...@gmail.com

created issue #1

Nov 20, 2018 08:10PM

Artifact used (ex. androidx.tvprovider:tvprovider::1.0.0):
Version used: 1.0.0
Theme used: None
Devices/Android versions reproduced on: Nvidia Shield running Android 8.

When trying to update an existing preview channel using PreviewChannelHelper from the above library a NullPointerException is thrown.
It seems that the description of the current channel is not set and when the helper tries to retain it and set it on the new channel it throw the exception.

Here it is:
java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.String java.lang.CharSequence.toString()' on a null object reference
at androidx.tvprovider.media.tv.PreviewChannel$Builder.setDescription(PreviewChannel.java:400)
at androidx.tvprovider.media.tv.PreviewChannel.fromCursor(PreviewChannel.java:98)
at androidx.tvprovider.media.tv.PreviewChannelHelper.getPreviewChannel(PreviewChannelHelper.java:209)
at androidx.tvprovider.media.tv.PreviewChannelHelper.updatePreviewChannel(PreviewChannelHelper.java:229)
at dk.youtec.drchannels.preview.BasePreviewUpdater.setupPreviewChannel(BasePreviewUpdater.kt:157)
at dk.youtec.drchannels.preview.BasePreviewUpdater.doWork(BasePreviewUpdater.kt:47)
at androidx.work.Worker$1.run(Worker.java:57)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636)
at java.lang.Thread.run(Thread.java:764)

Comments

ve...@google.com <ve...@google.com> Nov 22, 2018 06:40AM

Assigned to ve...@google.com.

ve...@google.com <ve...@google.com> #2Nov 22, 2018 11:12AM

Hi - thanks for raising this, I'll dig into our SwipeDismissableNavHost and try to find out why we didn't support the back button already. Will report back on this thread.

cl...@gmail.com <cl...@gmail.com> #3Nov 22, 2018 12:27PM

An early draft of SwipeDismissableNavHost did implement back button support, but it was thought not to be required - we will submit a change to add the support back again.

ve...@google.com <ve...@google.com> #4Nov 27, 2018 08:33AM

Project: platform/frameworks/support
Branch: androidx-main

commit 78d498661680a95d2705d5e6dbb1c0438c50fa30
Author: stevebower <stevebower@google.com>
Date: Tue Dec 14 13:42:48 2021

Support back button in SwipeDismissableNavHost.

Added back button handling for navigation to
SwipeDismissableNavHost, using the implementation
from Compose Material NavHost. This enables use
of the emulator's back button for local testing,
as well as in any devices that support a hardware back button.

Test: Run tests for wear.compose.navigation.

Bug: 210205624

Relnote: "We have added a back button handler to
SwipeDismissableNavHost, so that pressing
back navigates to the previous level
in the navigation hierarchy."
Change-Id: I5b08689b1651c1aae5f038f058956007df398909

M wear/compose/compose-navigation/build.gradle
M wear/compose/compose-navigation/src/androidTest/kotlin/androidx/wear/compose/navigation/SwipeDismissableNavHostTest.kt
M wear/compose/compose-navigation/src/main/java/androidx/wear/compose/navigation/SwipeDismissableNavHost.kt

https://android-review.googlesource.com/1922537

ad...@google.com <ad...@google.com> Nov 28, 2019 06:56AM

Reassigned to ad...@google.com.

ia...@google.com <ia...@google.com> #5Apr 25, 2020 02:37AM

This can end up getting triggered in a lot of ways. It looks like a variety of methods use the fromCursor method to construct the PreviewChannel. This creates a builder and tries to set all the values from the builder. Description is explicitly NOT required when constructing a PreviewChannel but once you've stored one in the database without a description, you get NPEs from no description:

https://cs.android.com/androidx/platform/frameworks/support/+/androidx-master-dev:tv-provider/tv-provider/src/main/java/androidx/tvprovider/media/tv/PreviewChannel.java;l=98

This is especially painful because it makes most of the regular ways of getting a PreviewChannel broken. For example, just doing PreviewChannelHelper(context).allChannels is enough to throw the NPE.

ra...@google.com <ra...@google.com> #6May 5, 2020 06:25PM

Reassigned to ra...@google.com.

Hi Adarsh,

I'm planning to work on the fix here.
Lemme know in case this is already is progress or has been fixed.

ra...@google.com <ra...@google.com> #7May 6, 2020 05:18PM

Raised a CL for review of the fix :

https://android-review.googlesource.com/c/platform/frameworks/support/+/1304173

ap...@google.com <ap...@google.com> #8May 6, 2020 06:45PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 6a15553ecd52c81df5bfa4cb37c65e409945122d
Author: Rahul Arora <raharora@google.com>
Date: Wed May 06 15:24:18 2020

Adds nullability annotations to PreviewChannel#setDescription

Bug: 119800858

Test: Modified PreviewChannelTest.java#testFullyPopulatedPreviewChannel() by setting description to null and ommitting assertEquals check for previewChannel#description.

./gradlew updateApi : Successful
./gradlew tvprovider:tvprovider:assemble : Successful
./gradlew createArchive : Successful
./gradlew buildOnServer : Successful

Change-Id: I1d399bdda9c003f54c51dbcbf7f15ea1a8713ba9

M tv-provider/tv-provider/api/1.1.0-alpha01.txt
M tv-provider/tv-provider/api/current.txt
M tv-provider/tv-provider/api/public_plus_experimental_1.1.0-alpha01.txt
M tv-provider/tv-provider/api/public_plus_experimental_current.txt
M tv-provider/tv-provider/api/restricted_1.1.0-alpha01.txt
M tv-provider/tv-provider/api/restricted_current.txt
M tv-provider/tv-provider/src/main/java/androidx/tvprovider/media/tv/PreviewChannel.java

https://android-review.googlesource.com/1304173

ra...@google.com <ra...@google.com> #9May 13, 2020 05:57PM

Status: Assigned (reopened)

Raised another CL for handling the case where developer is using the same builder to populate different PreviewChannel Objects.

https://android-review.googlesource.com/c/platform/frameworks/support/+/1310577

ap...@google.com <ap...@google.com> #10Jun 2, 2020 07:04PM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 1eacea96a3d01613e229439bbe362a56f3368daf
Author: Rahul Arora <raharora@google.com>
Date: Wed May 13 21:26:15 2020

Setting PreviewChannel#description as empty for null cases

Bug : 119800858

This is an improvement over the previous CL which added the null check inside the description setter.

https://android-review.googlesource.com/c/platform/frameworks/support/+/1304173

Use Cases : If a developer is using the same builder to construct different PreviewChannel Objects by overriding different fields, then setting a null description might result in setting the description of the previous builder object's data in the current scenario.

Test: Unit-test imitating the above use case
./gradlew buildOnServer : Successful

Change-Id: I82e0b1250015b95b405180e7fd95f91d6e1e83c4

M tv-provider/tv-provider/src/androidTest/java/androidx/tvprovider/media/tv/PreviewChannelHelperTest.java
M tv-provider/tv-provider/src/main/java/androidx/tvprovider/media/tv/PreviewChannel.java

https://android-review.googlesource.com/1310577

ra...@google.com <ra...@google.com> #11Sep 2, 2020 07:15AM

Marked as fixed.

This was fixed and released as part of latest TV Provider release.

https://developer.android.com/jetpack/androidx/releases/tvprovider#1.1.0-alpha01

I'm resolving this ticket.
Feel free to re-open this in case of any issues.

ap...@google.com <ap...@google.com> #12May 1, 2023 05:27AM