rust-dirstatemap: properly decrement counter for tracked descendants
I found this bug when writing unit tests after the fact for the `DirstateMap`.
We never decremented the tracked descendants counter since we were always
resetting the node data before reading it. This also drops the use of `state`,
in favor of the new API to get that information.
Differential Revision: https://phab.mercurial-scm.org/D12431
$ HGENCODING=utf-8
$ export HGENCODING
$ try() {
> hg debugrevspec --debug $@
> }
$ log() {
> hg log --template '{rev}\n' -r "$1"
> }
$ hg init repo
$ cd repo
$ try 'p1()'
(func
(symbol 'p1')
None)
* set:
<baseset []>
$ try 'p2()'
(func
(symbol 'p2')
None)
* set:
<baseset []>
$ try 'parents()'
(func
(symbol 'parents')
None)
* set:
<baseset+ []>
null revision
$ log 'p1()'
$ log 'p2()'
$ log 'parents()'
working dir with a single parent
$ echo a > a
$ hg ci -Aqm0
$ log 'p1()'
0
$ log 'tag() and p1()'
$ log 'p2()'
$ log 'parents()'
0
$ log 'tag() and parents()'
merge in progress
$ echo b > b
$ hg ci -Aqm1
$ hg up -q 0
$ echo c > c
$ hg ci -Aqm2
$ hg merge -q
$ log 'p1()'
2
$ log 'p2()'
1
$ log 'tag() and p2()'
$ log 'parents()'
1
2
$ cd ..