#3029 ratsubst,fullratsubst does not work correctly applied to sum

[dan hayes]

wxMaxima version: 13.4.0
Maxima version: 5.31.1
Maxima build date: 2013-09-24 09:49:12
Host type: i686-pc-mingw32
Lisp implementation type: GNU Common Lisp (GCL)
Lisp implementation version: GCL 2.6.8

(assume(positive,true),assume_pos_pred:true,showtime:true,ratprint:false,load("lrats"),simpsum:true,load(simplify_sum));

:::text
(t:(-1)^(k+m)*sum(sum(binomial(k+m,j)*(1+(-1)^(p-2*j+m))*%i^(p-2*j)*binomial(m,p-2*j),j,max(ceiling((p-m)/2),0)
,min(k,p/2))  *x[1]^(2*k+m-p)*x[2]^p,p,0,2*k+m)
,t1:lratsubst(p=mod(m,2)+2*s,t),ldisp([t ]),ldisp(["t1  ",t1]))

t1 has NO sum over s. Also used fullratsubst and same thing.

[Rupert Swarbrick]

I'm sorry but I'm struggling to understand this bug report. Please can you explain what you expected to see compared to what you actually see? I'm afraid I don't have any intuition for what to expect from summing this complicated pile of binomial coefficients...