Program: 70529
Project: 70529
Buggy source:
@Override protected void onCreate(Bundle savedInstanceState){
  super.onCreate(savedInstanceState);
  bind=DataBindingUtil.setContentView(this,R.layout.activity_signin);
  auth=FirebaseAuth.getInstance();
  database=FirebaseDatabase.getInstance();
  isAnimated=false;
  dialog=new ProgressDialog(this);
  dialog.setMessage(getResources().getString(R.string.loading));
  dialog.setCancelable(false);
  signInCallback=new OnCompleteListener<AuthResult>(){
    @Override public void onComplete(    @NonNull Task<AuthResult> task){
      final FirebaseUser user=auth.getCurrentUser();
      if (task.isSuccessful() && user != null) {
        database.getReference().child("String_Node_Str").child(user.getUid()).child("String_Node_Str").addListenerForSingleValueEvent(new ValueEventListener(){
          @Override public void onDataChange(          DataSnapshot dataSnapshot){
            dialog.cancel();
            if (dataSnapshot.getValue() == null) {
              if (lastOpen == null) {
                startActivity(new Intent(SigninActivity.this,ProfileSetupActivity.class));
                return;
              }
              Intent i=new Intent(SigninActivity.this,ProfileSetupActivity.class);
              i.putExtra(ProfileSetupActivity.EXTRA_SETUP_METHOD,lastOpenId);
              startActivity(i,ActivityOptionsCompat.makeSceneTransitionAnimation(SigninActivity.this,lastOpen,"String_Node_Str").toBundle());
            }
 else {
              startActivity(new Intent(SigninActivity.this,MainActivity.class));
            }
            finish();
          }
          @Override public void onCancelled(          DatabaseError databaseError){
            dialog.cancel();
          }
        }
);
      }
 else {
        dialog.cancel();
        showToast(R.string.error);
        bind.password.setText("String_Node_Str");
      }
    }
  }
;
  bind.center.setOnClickListener(new View.OnClickListener(){
    @Override public void onClick(    View v){
      if (isAnimated)       return;
      isAnimated=true;
      showAnimation();
    }
  }
);
  googleSetup();
  emailPasswordSetup();
  facebookSetup();
  phoneSetup();
  loginSetup();
  twitterSetup();
}

Fixed version (ground truth):
@Override protected void onCreate(Bundle savedInstanceState){
  super.onCreate(savedInstanceState);
  bind=DataBindingUtil.setContentView(this,R.layout.activity_signin);
  auth=FirebaseAuth.getInstance();
  database=FirebaseDatabase.getInstance();
  isAnimated=false;
  dialog=new ProgressDialog(this);
  dialog.setMessage(getResources().getString(R.string.loading));
  dialog.setCancelable(false);
  signInCallback=new OnCompleteListener<AuthResult>(){
    @Override public void onComplete(    @NonNull Task<AuthResult> task){
      final FirebaseUser user=auth.getCurrentUser();
      if (task.isSuccessful() && user != null) {
        database.getReference().child("String_Node_Str").child(user.getUid()).child("String_Node_Str").addListenerForSingleValueEvent(new ValueEventListener(){
          @Override public void onDataChange(          DataSnapshot dataSnapshot){
            dialog.cancel();
            if (dataSnapshot.getValue() == null) {
              if (lastOpenImg == null || lastOpenTv == null) {
                startActivity(new Intent(SigninActivity.this,ProfileSetupActivity.class));
                return;
              }
              Intent i=new Intent(SigninActivity.this,ProfileSetupActivity.class);
              i.putExtra(ProfileSetupActivity.EXTRA_SETUP_METHOD,lastOpenId);
              startActivity(i,ActivityOptionsCompat.makeSceneTransitionAnimation(SigninActivity.this,new Pair<View,String>(lastOpenImg,"String_Node_Str"),new Pair<View,String>(lastOpenTv,"String_Node_Str")).toBundle());
            }
 else {
              startActivity(new Intent(SigninActivity.this,MainActivity.class));
            }
            finish();
          }
          @Override public void onCancelled(          DatabaseError databaseError){
            dialog.cancel();
          }
        }
);
      }
 else {
        dialog.cancel();
        showToast(R.string.error);
        bind.password.setText("String_Node_Str");
      }
    }
  }
;
  bind.center.setOnClickListener(new View.OnClickListener(){
    @Override public void onClick(    View v){
      if (isAnimated)       return;
      isAnimated=true;
      showAnimation();
    }
  }
);
  googleSetup();
  emailPasswordSetup();
  facebookSetup();
  phoneSetup();
  loginSetup();
  twitterSetup();
}