Is this a bug in lsqcurvefit?

When I run this simple test of lsqcurvefit (this is R2018a), I get errors.

    opts=optimoptions(@lsqcurvefit,'SpecifyObjectiveGradient',true,...
                                    'JacobianMultiplyFcn',@Jfun);

     p=lsqcurvefit(@modelfun,2,10,11,[],[],opts)



    function [y,Jinfo]=modelfun(p,xdata)

      y=xdata-p;
      Jinfo=0;

    end

    function out=Jfun(Jinfo,Y,flag)

      out=0;

    end

The errors are

Too many input arguments.

Error in lsqcurvefit/jacobmult (line 291)
         W = feval(mtxmpy_xdata,Jinfo,Y,flag,XDATA,varargin{:});

Error in snls (line 199)
g = feval(mtxmpy,A,fvec(:,1),-1,varargin{:});

Error in lsqncommon (line 167)
            snls(funfcn,xC,lb,ub,flags.verbosity,options,defaultopt,initVals.F,initVals.J,caller,
            ...

Error in lsqcurvefit (line 271)
    lsqncommon(funfcn,xCurrent,lb,ub,options,defaultopt,allDefaultOpts,caller,...

Error in test1 (line 6)
     p=lsqcurvefit(@modelfun,2,10,11,[],[],opts)

Looking at line 291 in lsqcurvefit shows that it is in fact trying to pass xdata as a 4th argument to the JacobMult function

     function W = jacobmult(Jinfo,Y,flag,varargin)
         W = feval(mtxmpy_xdata,Jinfo,Y,flag,XDATA,varargin{:});
     end

I can see why it would make sense to pass xdata to the user-provided JacobMult function, in addition to Jinfo,Y, and flag, but nowhere in the documentation does it say to format the JacobMult function this way. Is this a coding bug or a documentation bug?

[Matt J]

Another question, sort of on the same subject. When the JacobianMutiplyFcn is used, what does the solver return for the jacobian output in the following?

[x,resnorm,residual,exitflag,output,lambda,jacobian] = lsqcurvefit(___)