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
#require execbit
$ hg init repo
$ cd repo
$ echo foo > foo
$ chmod 644 foo
$ hg ci -qAm '644'
$ chmod 755 foo
$ hg ci -qAm '755'
reverting to rev 0
$ hg revert -a -r 0
reverting foo
$ hg st
M foo
$ hg diff --git
diff --git a/foo b/foo
old mode 100755
new mode 100644
$ cd ..