Fix array == null error in AccessibilityBridge

[GuaiYiHu]

08-16 06:23:59.641 23012 23012 E flutter : [ERROR:flutter/fml/platform/android/jni_util.cc(182)] java.lang.IllegalArgumentException: array == null at android.opengl.Matrix.multiplyMM(Native Method) at io.flutter.view.AccessibilityBridge$SemanticsNode.updateRecursively(Unknown Source:28) at io.flutter.view.AccessibilityBridge$SemanticsNode.updateRecursively(Unknown Source:240) at io.flutter.view.AccessibilityBridge$SemanticsNode.updateRecursively(Unknown Source:240) at io.flutter.view.AccessibilityBridge$SemanticsNode.updateRecursively(Unknown Source:240) at io.flutter.view.AccessibilityBridge$SemanticsNode.updateRecursively(Unknown Source:240) at io.flutter.view.AccessibilityBridge$SemanticsNode.access$4900(Unknown Source:0) at io.flutter.view.AccessibilityBridge.updateSemantics(Unknown Source:192) at io.flutter.view.AccessibilityBridge$1.updateSemantics(Unknown Source:21) at io.flutter.embedding.engine.FlutterJNI.updateSemantics(Unknown Source:9) at android.os.MessageQueue.nativePollOnce(Native 08-16 06:23:59.641 23012 23012 F flutter : [FATAL:flutter/shell/platform/android/platform_view_android_jni_impl.cc(1214)] Check failed: fml::jni::CheckException(env).

Fix array == null error

https://github.com/flutter/flutter/issues/89834 https://github.com/flutter/flutter/issues/31139

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[GuaiYiHu]

Will any one review this commit?

[zanderso]

From PR triage: @stuartmorgan Do you know who would be the right reviewer for this change? Should the concern from @chinmaygarde be addressed?

[stuartmorgan]

@chunhtai Are you familiar with this code? It looks like you are one of the people who has been most active in this file.

[GaryQian]

@GuaiYiHu Can you provide a reproduction of the crash so we can investigate what the correct course of action is? Either mitigate the crash with this PR or fix the upstream root bug.

[chinmaygarde]

I think this is a safe fix either way and the same pattern followed elsewhere is being followed here.

[chunhtai]

I am ok if we add an assert so that we still have a chance to catch the root cause but avoiding crash in production. @GuaiYiHu Can you add an assert that it should never be null?

[GuaiYiHu]

I am ok if we add an assert so that we still have a chance to catch the root cause but avoiding crash in production. @GuaiYiHu Can you add an assert that it should never be null?

sure

[zanderso]

From PR review triage: @GuaiYiHu are you interested in continuing with this PR? If so, it looks like the next step is to follow-up on the feedback from @chunhtai.

[GuaiYiHu]

From PR review triage: @GuaiYiHu are you interested in continuing with this PR? If so, it looks like the next step is to follow-up on the feedback from @chunhtai.

busy these days, will do this on my holiday from tomorrow.😃

[GuaiYiHu]

From PR review triage: @GuaiYiHu are you interested in continuing with this PR? If so, it looks like the next step is to follow-up on the feedback from @chunhtai.

@chunhtai @zanderso all done, please review.

[GuaiYiHu]

@chunhtai Pushed again, all checks have passed, please review, thanks a lot.

[chunhtai]

Can you add a test to test if it throw assertionError when a node has uninitialized transform, and mock the BuildConfig to test it doesn't crash?

[GuaiYiHu]

Can you add a test to test if it throw assertionError when a node has uninitialized transform, and mock the BuildConfig to test it doesn't crash?

I'm afraid I cannot reproduce this crash, it appears just occasionally.

[chunhtai]

Can you add a test to test if it throw assertionError when a node has uninitialized transform, and mock the BuildConfig to test it doesn't crash?

I'm afraid I cannot reproduce this crash, it appears just occasionally.

Can you create test similar to ones in AccessibilityBridgeText that sends a TestSemanticsUpdate with a node that contains a child id but not part of the update, for example, you can duplicate TestSemanticsNode but in the addToBuffer method comment out the last part that add child to the update

[GaryQian]

@GuaiYiHu Did you still plan on adding a test or finding a way to repro this bug?

[chinmaygarde]

From Triage: This looks like a benign change that seems to be hard to test and follows patterns consistent with the rest of the code. It's low risk, fixes crashes found in the wild and has an LGTM. Let's land this and file followup issues as needed.