Follows-up c943f75.
* Use foreach to iterate the list of tokens, instead of i-to-length.
* Remove the redundant 'retval = false' assignment, as this was
within an `if (!$retval)` block where the only previous assignment
to it was either retval = 1 or retval = false. Hence redundant.
* Remove the conditional that made the list only checked if the
list was not identical to `[ 0 => "" ]`.
It is unclear to me why this check existed.
I can imagine one of two scenarios, neither of which appears
to be the case:
1. Maybe the scratch list contains 10 tokens plus an empty string,
and if we see it only contains that, we know it's logically empty
and don't "need" to iterate the list.
Except... iterating the list is cheap, so why bother?
2. Maybe the scratch list contains 10 tokens plus an empty string,
and we don't want to allow the empty string to be considered
a valid scratch token to we skip the loop if that's the only
one left.
Except... if that were the case we'd be in trouble as it
isn't being disallowed when the list contains other items
still. And again, afaik it never contains an empty string,
and hopefully empty input is already rejected by now.
Neither of these are good reasons to remove the code without
knowing what it was for though, so I'd rather we figure this
out before merging. I can restore the check if it's non-trivial
to find out.
Bug: T256918
Change-Id: Ide4160bdc18bc47da9632791fb4321e44d6d115a
6b106fe10c