I've started getting

/home/nilsson/pike/lib/modules/String.pmod/module.pmod:98: Warning: An expression of type string | int | !mixed cannot be assigned to a variable of type int.

after the changes in there. It should be possible to work out that

int sz = min(@map(strs, sizeof));

is always the correct type.

After some tests, it seems that the problem is the type of min():

array(string) strs; typeof(map(strs, sizeof));

(1) Result: array(int)

typeof(min(@map(strs, sizeof)));

(2) Result: string | int | !mixed

typeof(min());

(3) Result: string | !mixed

min();

(4) Result: 0

I'll see what I can do.