fix(player): Fix scaleX being NaN on minimize to background app switch

[TobiGr]

What is it?

• Bugfix (user facing)

Description of the changes in your PR

This aims to fix the following Exception which might occour when watching a live stream and switching the app while 'minimize to backgorund' is enabled:

java.lang.IllegalArgumentException: Cannot set 'scaleX' to Float.NaN
	at android.view.View.sanitizeFloatPropertyValue(View.java:17479)
	at android.view.View.sanitizeFloatPropertyValue(View.java:17453)
	at android.view.View.setScaleX(View.java:16822)
	at org.schabi.newpipe.views.ExpandableSurfaceView.onLayout(ExpandableSurfaceView.java:71)

For the fill stacktrace and description, see #12925 (comment) and #12955.

scaleX is set in onMeasure() in which width could be 0 in theory and this leading to a division by zero of a float which results in an assignment of Float.NaN.

The set aspectRatio is, but must not be not finite, which causes an assignment of Float.NaN.

Remarks

• The crash was observed on Android 11 (30) and 12 (31).
• The crash can be caused by different actions (see [nightly] Minimize to background player option is not working properly  #12955, [nightly] App crashes when pressing system Back button after opening Downloads page #12957, [nightly] Crash when returning to the main player from a popup video. #12959).

Note for reviewers

The second finding actually fixes the crash while the first does not as noted in #12955. But I'd like to keep both safeguards. I was initially expecting to find a View that was not hidden or destroyed. The aspect ration seems to be not finite which means that the video width and height retrieved from Exoplayer are 0. This could mean that the player is not detached or destroyed as expected. However, I am unable to reproduce this crash and this is more a symptom fix than actually taking a shot at the root cause. If someone is able to reproduce this, please take a look at it!

Fixes the following issue(s)

This is a potential fix for the stacktrace given in #12925 (comment)

• Fixes [nightly] Minimize to background player option is not working properly  #12955
• Fixes [nightly] App crashes when pressing system Back button after opening Downloads page #12957
• Close [nightly] Crash when returning to the main player from a popup video. #12959

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.
• The proposed changes follow the AI policy.
• I tested the changes using an emulator or a physical device.

[TobiGr]

@theimpulson This PR fixes crashes which have not been reported in the 0.28.0 release and only with recent nightly releases. We did not touch any related files recently which leads me to the suspicion that a dependecy update might be the cause for this issue. Any ideas?

[theimpulson]

@theimpulson This PR fixes crashes which have not been reported in the 0.28.0 release and only with recent nightly releases. We did not touch any related files recently which leads me to the suspicion that a dependecy update might be the cause for this issue. Any ideas?

I think it might be exoplayer. I see this on exoplayer 2.19.0 changelog:

Make MediaCodecVideoRenderer report a VideoSize with a width and height of 0 when the renderer is disabled. Player.Listener.onVideoSizeChanged is called accordingly when Player.getVideoSize() changes. With this change, ExoPlayer's video size with MediaCodecVideoRenderer has a width and height of 0 when Player.getCurrentTracks does not support video, or the size of the supported video track is not yet determined.

[TobiGr]

Thanks. That's the cause. I kept the previous two commits to ensure no bad values are used and added a commit to tackle the cause where it should be.

The interesting question is why I am not able to reproduce the error on the emulator or my phone. But I don't think we have to answer that 😅

[theimpulson]

LGTM