1-2 Some low spec devices are experiencing crashes when using Firefox-on-Android to run the web app option.

[manukautech]

All trials with Firefox on Android are now crashing after running 5 to 15 min.
I do know that the last successful long run field trial of this configuration was 05 Jan 2019. The next trial which crashed was 18 Jan 2019.
In extensive testing over the last 2 days I can find nothing wrong yet with the code.

What is "crashing"?
The screen returns to its Android system home page.
Firefox is still running but it has started a new session with a blank home page

• Hypothesis "Firefox bug" - There was a new version of Firefox on 09 Jan 2019 in between these dates so I need to include in my detective work the possibility that something has happened to a Firefox system function. The main candidate for investigation is:
  navigator.mediaDevices.getUserMedia(constraints)
• Hypothesis "Server-side Session Timeout" change of behaviour. Seems less likely because trials on Windows 10 devices show no sign of this or any other problem.

Current detective work is:

• Done - run trials with variations of smart phone configuration eg power managment, screen locking options - same crashing
• Done - run trials with Firefox beta - same crashing.
• Ongoing - Roll back to earlier versions of this app and test again - so far trials are all crashing
• Todo - Create a special simpified version of this app focussing on testing
  navigator.mediaDevices.getUserMedia(constraints)

[manukautech]

Experiment. 21 Jan 2019 - compare FireFox-on-Android and Google-Chrome-on-Android,
Phone is Vodafone VFD-513 running Android 7.1.1
An little challenge here is that Google Chrome goes to sleep when I lock the screen which is why Firefox has been the preferred browser. I have therefore downloaded and run a play store app "Keep Screen On". This enables long run trials with Google Chrome. I did both the Chrome run and the Firefox runs with "Keep Screen On" active.
Results:

• Google Chrome with front camera gives a stable run - I stopped it at 34 min
• Firefox with front camera and pointing at a static scene - crashes after 4 minutes
• Firefox with rear camera and pointing at a scene with motion happening - crashes after 4 minutes
  I assert that this is more evidence that Firefox has an issue.

What to do from here? Report this as a bug to the Firefox community? I can try this but it may help to have a Plan B = I will also do more with the Android app development pathway.

[manukautech]

I have now filed a Firefox bug report.
https://bugzilla.mozilla.org/show_bug.cgi?id=1521760

To prepare this I needed a simplified test app that I could let out as a public link. This tests the camera-handling code only and has no server-side or any other storage of the images. All test results welcome:
https://manukautech.github.io/xmrt/

This test app has an associated source repository:
https://github.com/manukautech/xmrt

The emerging picture. The crash problem is only appearing on low cost, low resource phones. However these devices could be playing the useful role of "canary down the mineshaft" in that they are highlighting a memory management issue that could be more difficult to investigate on a phone with more memory where this could show up as a lurking rare intermittent problem.

[manukautech]

More testing is confirming that the web app on Firefox-for-Android runs reliably on most devices. Ref:
https://bugzilla.mozilla.org/show_bug.cgi?id=1521760

I am therefore changing the title from:
1-2 Firefox-on-Android is crashing this app on low spec devices after 5 to 15 min of operation
to:
1-2 Some low spec devices are experiencing crashes when using Firefox-on-Android to run the web app option.