rust-lang/rust — pull request #16590 by nham (2014-08-18 22:00:04+00:00)
Title: Fix underflow in core::str::Searcher::new for haystacks of length < 20

This incidentally fixes #16589, because it will cause `MatchIndices` to use `NaiveSearcher` instead of `TwoWaySearcher`, but I'm not sure #16589 should be closed until the underlying problem in `TwoWaySearcher` is found.