view tests/test-merge-closedheads.t @ 32334:6e0d1043e8fc

fsmonitor: acquire localrepo.wlock prior to emitting hg.update state

we see some weird things in the watchman logs where the mercurial
process is seemingly confused about which hg.update state it is publishing
through watchman.

On closer examination, we're seeing conflicting pids for the clients involved
and this implies a race.

To resolve this, we extend the wlock around the state-enter/state-leave
events that are emitted to watchman.

Test Plan:
Some manual testing:

In one window, run this, and then checkout a different rev:

```
$ watchman -p -j <<<'["subscribe", "/data/users/wez/fbsource", "wez", {"expression": ["name", ".hg/updatestate"]}]'
{
    "version": "4.9.0",
    "subscribe": "wez",
    "clock": "c:1495034090:814028:1:312576"
}
{
    "state-enter": "hg.update",
    "version": "4.9.0",
    "clock": "c:1495034090:814028:1:312596",
    "unilateral": true,
    "subscription": "wez",
    "metadata": {
        "status": "ok",
        "distance": 125,
        "rev": "a1275d79ffa6c58b53116c8ec401c275ca6c1e2a",
        "partial": false
    },
    "root": "/data/users/wez/fbsource"
}
{
    "root": "/data/users/wez/fbsource",
    "metadata": {
        "status": "ok",
        "distance": 125,
        "rev": "a1275d79ffa6c58b53116c8ec401c275ca6c1e2a",
        "partial": false
    },
    "subscription": "wez",
    "unilateral": true,
    "version": "4.9.0",
    "clock": "c:1495034090:814028:1:312627",
    "state-leave": "hg.update"
}
```

Tailed the watchman log file and looked for invalid state assertion errors,
then ran my `rebase-all` script to update/rebase all of my heads.

Didn't trigger the error condition (but couldn't reliably trigger it previously
anyway), and the output captured above shows that the states are being emitted
correctly.

  $ hgcommit() {
  >    hg commit -u user "$@"
  > }

  $ hg init clhead
  $ cd clhead

  $ touch foo && hg add && hgcommit -m 'foo'
  adding foo
  $ touch bar && hg add && hgcommit -m 'bar'
  adding bar
  $ touch baz && hg add && hgcommit -m 'baz'
  adding baz

  $ echo "flub" > foo
  $ hgcommit -m "flub"
  $ echo "nub" > foo
  $ hgcommit -m "nub"

  $ hg up -C 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ echo "c1" > c1
  $ hg add c1
  $ hgcommit -m "c1"
  created new head
  $ echo "c2" > c1
  $ hgcommit -m "c2"

  $ hg up -C 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo "d1" > d1
  $ hg add d1
  $ hgcommit -m "d1"
  created new head
  $ echo "d2" > d1
  $ hgcommit -m "d2"
  $ hg tag -l good

fail with three heads
  $ hg up -C good
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  abort: branch 'default' has 3 heads - please merge with an explicit rev
  (run 'hg heads .' to see heads)
  [255]

close one of the heads
  $ hg up -C 6
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hgcommit -m 'close this head' --close-branch

succeed with two open heads
  $ hg up -C good
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg up -C good
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hgcommit -m 'merged heads'

hg update -C 8
  $ hg update -C 8
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

hg branch some-branch
  $ hg branch some-branch
  marked working directory as branch some-branch
  (branches are permanent and global, did you want a bookmark?)
hg commit
  $ hgcommit -m 'started some-branch'
hg commit --close-branch
  $ hgcommit --close-branch -m 'closed some-branch'

hg update default
  $ hg update default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
hg merge some-branch
  $ hg merge some-branch
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
hg commit (no reopening of some-branch)
  $ hgcommit -m 'merge with closed branch'

  $ cd ..