Consecutive concatenation of streams may leads to stack overflow due to recursive invocation of estimateSize():

int count = 20000;
IntStream s[] = new IntStream[count];
for (int i = 0; i < count; i++) {
        s[i] = Arrays.stream(new int[1]);
}
IntStream cs = s[0];
for (int i = 1; i < count; i++) {
        cs = IntStream.concat(cs, s[i]);
}