Fixes #1815 Needed for https://github.com/nextcloud/spreed/pull/6896

Once a RTCPeerConnection is established new offers can still be received for that connection. These offers will update/renegotiate the connection (for example, to add a video track to an audio only connection) and need to be handled like the offers to establish the original connection (the offer needs to be set as the remote description and a local answer needs to be created for it, set as the local description and sent to the other peer).

Pending:

• [ ] Trigger renegotiations only if update is provided in the offer
• [ ] Reset connections if an offer without update is received (as done in the WebUI; this is actually a bug in the Android app)
• [ ] Ensure that everything works as expected also for previous Talk versions both with and without HPB (it should, but... you know :-) )

How to test

• Setup https://github.com/nextcloud/spreed/pull/6896 (note that a specific pull request for the external signaling server is also needed)
• In the browser, start a call and, in the device checker shown before actually starting the call, select an audio device and no video device
• In the Android app, join the call
• In the browser, open the device settings, select a video device and close the device settings
• Enable video

Result with this pull request

In the Android app the video is now visible (note that, due to a bug in the WebUI, the video may be visible even before being actually enabled in the browser)

Result without this pull request

In the Android app the video is not visible

Lint

Type	master	PR
Warnings	156	156
Errors	1	1

SpotBugs (new)

Warning Type	Number
Bad practice Warnings	9
Correctness Warnings	91
Experimental Warnings	2
Internationalization Warnings	9
Malicious code vulnerability Warnings	115
Performance Warnings	27
Security Warnings	2
Dodgy code Warnings	158
Total	413

SpotBugs (master)

Warning Type	Number
Bad practice Warnings	9
Correctness Warnings	91
Experimental Warnings	2
Internationalization Warnings	9
Malicious code vulnerability Warnings	115
Performance Warnings	27
Security Warnings	2
Dodgy code Warnings	158
Total	413

/rebase

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/1823-talk.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud Talk app.

Codacy

Lint

Type	master	PR
Warnings	112	112
Errors	1	1

SpotBugs

Category	Base	New
Bad practice	4	4
Correctness	75	75
Dodgy code	315	315
Experimental	2	2
Internationalization	9	9
Malicious code vulnerability	54	54
Performance	22	22
Security	2	2
Total	483	483

Codacy

Lint

Type	master	PR
Warnings	112	111
Errors	1	1

SpotBugs

Category	Base	New
Bad practice	4	4
Correctness	29	30
Dodgy code	250	251
Experimental	2	2
Internationalization	6	6
Malicious code vulnerability	53	55
Performance	21	18
Security	2	2
Total	367	368

SpotBugs increased!

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/1823-talk.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud Talk app.

Codacy

Lint

Type	master	PR
Warnings	111	111
Errors	0	0

SpotBugs

Category	Base	New
Correctness	12	12
Dodgy code	174	174
Internationalization	5	5
Malicious code vulnerability	3	3
Performance	10	11
Security	2	2
Total	206	207

SpotBugs increased!

APK file: https://www.kaminsky.me/nc-dev/android-artifacts/1823-talk.apk



To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud Talk app.

Whats the status?