Short of either using some other regex engine other than ICU or writing our own, this simply can't be fixed. It's an ICU bug. Marking it as a 2.9 milestone won't get it fixed any faster.
Short of either using some other regex engine other than ICU or writing our own, this simply can't be fixed. It's an ICU bug. Marking it as a 2.9 milestone won't get it fixed any faster.