Replaced fixed window size for walkchangerevs with an increasing one. Window sizes starts at 8 (for good interactiveness) and doubles with each window until it is 512, which seems to be the maximum efficient value.

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "0 0"
hg verify
hg parents
hg status
hg undo
hg verify
hg parents
hg status