Issue in puiseux

[sachihashimoto]

I'm running into the following problem.

I have this code:

R_Q<x> := PolynomialRing(Rationals());
f := x^16 - 4*x^8 + 16; p := 3;
X := HyperellipticCurve(f);
Per := PeriodMatrix(CurveExtra(X));
G,m := GeometricEndomorphismRepresentation(Per, RationalsExtra());
E := EndomorphismRepresentation(G,RationalsExtra(),m);
Correspondence(X, X, E[5]);

It gives me this error. What is going on?

In file "/Users/sachihashimoto/Repos/CHIMP/endomorphisms/endomorphisms/magma/puiseux/Branches.m", line 84, column 18:
>>     j0 := Minimum([ j : j in [1..gX] | row[j] ne 0 ]);
                    ^
Runtime error in 'Minimum': Argument 1 is not non-empty

[edgarcosta]

This error originally happened at line 64, which we fixed temporarily with

js := [ j : j in [1..gX] | row[j] ne 0 ];
if #js eq 0 then
    continue;
end if;
j0 := Minimum(js);

but before applying the same fix again, I need to understand how the output of this function will be used