Root cause of "ringing survives reject on old Android":
1. startRinging() was NOT idempotent. When CallManager re-emitted
IncomingCall state (e.g., when another group member rejected while
still ringing), the state collector called startRinging() again.
startRingtone() OVERWROTE the ringtone field reference without
calling stop() on the old one. Old Ringtone instances kept
playing with no reachable reference — stopRingtone() on reject
only stopped the latest one.
2. Ringtone.isLooping was only set on API 28+. On older Android the
Ringtone class had documented reliability problems with stop().
MediaPlayer has reliable stop/release on all API levels and
supports looping universally.
Fixes:
- Switch from android.media.Ringtone to android.media.MediaPlayer.
- Make startRinging() idempotent — always call stopRinging() first
so any existing player/vibrator is torn down before a new one
starts.
- Add aggressive tracing logs throughout the reject path:
* CallAudioManager: instance id + thread on every start/stop,
MediaPlayer error listener, before-and-after player hashes.
* CallSession: log every state collector tick, log close() entry.
* CallManager: log rejectCall() entry/exit + transitionToEnded.
* CallNotificationReceiver: log every action with state transitions.
With these logs, if ringing still survives reject we can trace
exactly which primitive is failing.
https://claude.ai/code/session_019yNnDjGKmJb19gadmojq54
Claude
7e93f82577