evolve: improve transaction related code to use the lock module
Refactored some of the places where we are using locking in evolve to use
the lock module and write less code.
This should also fix a couple of bug where tr could be None at release time.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> hgext.graphlog=
> EOF
$ echo "evolve=$(echo $(dirname $TESTDIR))/hgext/evolve.py" >> $HGRCPATH
hg prev -B should move active bookmark
$ hg init
$ touch a
$ hg add a
$ hg commit -m 'added a'
$ touch b
$ hg add b
$ hg commit -m 'added b'
$ hg bookmark mark
$ hg bookmarks
* mark 1:6e742c9127b3
$ hg prev -B
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
[0] added a
$ hg bookmarks
* mark 0:a154386e50d1
hg next -B should move active bookmark
$ hg next -B
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
[1] added b
$ hg bookmarks
* mark 1:6e742c9127b3
hg prev should unset active bookmark
$ hg prev
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
[0] added a
$ hg bookmarks
mark 1:6e742c9127b3
hg next should move active bookmark
$ hg bookmark mark2
$ hg bookmarks
mark 1:6e742c9127b3
* mark2 0:a154386e50d1
$ hg next
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
[1] added b
$ hg bookmarks
mark 1:6e742c9127b3
mark2 0:a154386e50d1
$ hg bookmark -d mark2
$ hg bookmark mark
hg next/prev should not interfere with inactive bookmarks
$ touch c
$ hg add c
$ hg commit -m 'added c'
$ hg bookmark -r2 no-move
$ hg prev -B
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
[1] added b
$ hg bookmarks
* mark 1:6e742c9127b3
no-move 2:4e26ef31f919
$ hg next -B
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
[2] added c
$ hg bookmarks
* mark 2:4e26ef31f919
no-move 2:4e26ef31f919
$ hg up 1
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
(leaving bookmark mark)
$ hg next -B
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
[2] added c
$ hg bookmarks
mark 2:4e26ef31f919
no-move 2:4e26ef31f919
$ hg prev -B
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
[1] added b
$ hg bookmarks
mark 2:4e26ef31f919
no-move 2:4e26ef31f919