Introduce WP_Query::exists(), or have WP_Query::get() return false for non-existence
|Reported by:||nacin||Owned by:|
A query variable for an an endpoint with no value (/blah/, rather than /feed/rss2/) is set, but it is empty. WP_Query::get() returns an empty string when no QV is set, though, so you need to dig into WP_Query::query_vars directly. This is annoying. It should return false when the QV is not existence.
This should be rather backwards compatible, but WP_Query::exists() may be desired (also, or instead of). In this case, it won't work for core query vars, as _fill_query_vars() clears these, rather than unsets them. We should either change how _fill_query_vars() works, or something.