Index 0 beyond bounds for empty array crashes in SDL library (6.3.1)

[SunXiaoShan]

Bug Report

My project got two crashes from SDL library (iOS).
The number line are difference, but the root cause are same.
And it only happens on the iOS 13+.

*** -[__NSArrayM objectAtIndexedSubscript:]: index 0 beyond bounds for empty array
SDLScreenshotViewController.m line 37
SDLScreenshotViewController.m line 50

I leave some screen shots on the slack.
https://smartdevicelink.slack.com/archives/C0K32T48Y/p1569995789023500

Reproduction Steps

1. Launch the app
2. Wait a moment (2 min)
3. Crash(Random)

Expected Behavior

Not crash

OS & Version Information

• iOS Version: 13.1+
• SDL iOS Version: 6.3.1
• Test Mobile: iPhone X, iPhone MS MAX
• XCode: 11.0

[joeljfischer]

@SunXiaoShan Hello, can you please provide us with additional information or sample code that you've used to test. Do you know if the app you used supports the iOS 13+ UIWindowScene API (e.g. multiple windows)?

Also, did you test this against a module, Manticore, or another emulator?

[SunXiaoShan]

Test & Verify the v6.4.1.
This ticket could not reproduce again.