The function reading-quoted-or-escaped, which was added by:
2101afa
Doesn't check if there are characters before the quote like reading-quoted does. That causes the test data-with-whitespace-trim to not get an error when it expects it, in the "whitespace before quoted values is a parse error if we are
not trimming " case.
As it is now it look to me like reading-quoted-or-escaped is doing the wrong thing, because the pre-quote space ends up in the quoted string.