rust-dirstate-v2: show `unused_bytes` counter is not reset on total rewrite
This was picked up by @aalekseyev when doing unrelated debugging.
The Rust implementation was never resetting this counter, so a brand new file
would carry over the old counter.
As I write this, my counter is a supposed 7389089 unused bytes for a total of
170978 bytes in the data file. Feel free to post your own high score.
Differential Revision: https://phab.mercurial-scm.org/D12593
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..