combinationsReplacement recurses on x.slice(i, x.length), which at i = 0 is
as long as the input, so the only exit left is the k === 1 base case. For
k <= 0 the counter starts below that case and moves away from it, and the
recursion overflows the stack. The sibling combinations recurses on
x.slice(i + 1, x.length), runs out of input and returns [] for the same
arguments.
Guard the non-positive group size up front so both functions agree.
dualfroz
upstream