What probably matters to youSection of the release
What
The prompt input gained a second set of word motions modelled on readline: forward and backward word movement, kill-word and backward-kill-word, wired to Meta-Backspace, Meta-d and Ctrl-D, with killed text pushed onto a kill ring rather than simply deleted. The older word-motion behaviour is still present for the other mode.
Details
Word boundaries for the new mode come from a separate cache with readline's boundary rules, kept alongside the existing one.
Meta-d appends the killed word to the kill ring with a direction, so successive kills accumulate.
The check that interrupts on keypress now runs before the early return for control keys.
Which of the two modes is active is decided by an internal boolean that does not trace to any setting or command-line flag in this build.
Evidence
getReadlineWordBoundaries, killWord
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
