Program: 39882
Project: 39882
Buggy source:
void answer(@NonNull CallImpl call){
  Ln.i("String_Node_Str" + call);
  for (  CallImpl exist : _calls.values()) {
    Ln.d("String_Node_Str" + exist.getStatus());
    if (!exist.getKey().equals(call.getKey()) && (exist.getStatus() == Call.CallStatus.RINGING || exist.getStatus() == Call.CallStatus.CONNECTED)) {
      Ln.e("String_Node_Str");
      if (call.getAnswerCallback() != null) {
        call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
      }
      return;
    }
  }
  if (call.getDirection() == Call.Direction.OUTGOING) {
    Ln.e("String_Node_Str");
    if (call.getAnswerCallback() != null) {
      call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
    }
    return;
  }
  if (call.getDirection() == Call.Direction.INCOMING) {
    if (call.getStatus() == Call.CallStatus.CONNECTED) {
      Ln.e("String_Node_Str");
      if (call.getAnswerCallback() != null) {
        call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
      }
      return;
    }
 else     if (call.getStatus() == Call.CallStatus.DISCONNECTED) {
      Ln.e("String_Node_Str");
      if (call.getAnswerCallback() != null) {
        call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
      }
      return;
    }
  }
  stopPreview();
  CallContext.Builder builder=new CallContext.Builder(call.getKey()).setIsAnsweringCall(true).setIsOneOnOne(!call.isGroup());
  builder=builder.setMediaDirection(mediaOptionToMediaDirection(call.getOption()));
  _mediaEngine.setMediaConfig(new MediaCapabilityConfig(audioMaxBandwidth,videoMaxBandwidth,sharingMaxBandwidth));
  _callControlService.joinCall(builder.build(),false);
}

Fixed version (ground truth):
void answer(@NonNull CallImpl call){
  Ln.i("String_Node_Str" + call);
  for (  CallImpl exist : _calls.values()) {
    Ln.d("String_Node_Str" + exist.getStatus());
    if (!exist.getKey().equals(call.getKey()) && exist.getStatus() == Call.CallStatus.CONNECTED) {
      Ln.e("String_Node_Str");
      if (call.getAnswerCallback() != null) {
        call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
      }
      return;
    }
  }
  if (call.getDirection() == Call.Direction.OUTGOING) {
    Ln.e("String_Node_Str");
    if (call.getAnswerCallback() != null) {
      call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
    }
    return;
  }
  if (call.getDirection() == Call.Direction.INCOMING) {
    if (call.getStatus() == Call.CallStatus.CONNECTED) {
      Ln.e("String_Node_Str");
      if (call.getAnswerCallback() != null) {
        call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
      }
      return;
    }
 else     if (call.getStatus() == Call.CallStatus.DISCONNECTED) {
      Ln.e("String_Node_Str");
      if (call.getAnswerCallback() != null) {
        call.getAnswerCallback().onComplete(ResultImpl.error("String_Node_Str"));
      }
      return;
    }
  }
  stopPreview();
  CallContext.Builder builder=new CallContext.Builder(call.getKey()).setIsAnsweringCall(true).setIsOneOnOne(!call.isGroup());
  builder=builder.setMediaDirection(mediaOptionToMediaDirection(call.getOption()));
  _mediaEngine.setMediaConfig(new MediaCapabilityConfig(audioMaxBandwidth,videoMaxBandwidth,sharingMaxBandwidth));
  _callControlService.joinCall(builder.build(),false);
}