Bug: filter a directory, then clear the filter, then attempt to search.
On 0.9.0 the behavior is even worse: I cannot remove a filter (via :filter, no argument).
Since this commit you can chain filters together and I guess this destroyed the behavior of using :filter (with no arguments) to clear the filter. It was assumed that ":clear" is used to clear filters. I can work on this and send a patch that will make a :filter with no arguments act like a :clear.
I can confirm that :clear works, and that the original bug is no longer reproducible.