ui: add special-purpose atexit functionality
In spite of its longstanding use, Python's built-in atexit code is
not suitable for Mercurial's purposes, for several reasons:
* Handlers run after application code has finished.
* Because of this, the code that runs handlers swallows exceptions
(since there's no possible stacktrace to associate errors with).
If we're lucky, we'll get something spat out to stderr (if stderr
still works), which of course isn't any use in a big deployment
where it's important that exceptions get logged and aggregated.
* Mercurial's current atexit handlers make unfortunate assumptions
about process state (specifically stdio) that, coupled with the
above problems, make it impossible to deal with certain categories
of error (try "hg status > /dev/full" on a Linux box).
* In Python 3, the atexit implementation is completely hidden, so
we can't hijack the platform's atexit code to run handlers at a
time of our choosing.
As a result, here's a perfectly cromulent atexit-like implementation
over which we have control. This lets us decide exactly when the
handlers run (after each request has completed), and control what
the process state is when that occurs (and afterwards).
$ hg init repo
$ cd repo
$ echo foo > foo
$ hg ci -qAm 'add foo'
$ echo >> foo
$ hg ci -m 'change foo'
$ hg up -qC 0
$ echo bar > bar
$ hg ci -qAm 'add bar'
$ hg log
changeset: 2:effea6de0384
tag: tip
parent: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add bar
changeset: 1:ed1b79f46b9a
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..
don't show "(+1 heads)" message when pulling closed head
$ hg clone -q repo repo2
$ hg clone -q repo2 repo3
$ cd repo2
$ hg up -q 0
$ echo hello >> foo
$ hg ci -mx1
created new head
$ hg ci -mx2 --close-branch
$ cd ../repo3
$ hg heads -q --closed
2:effea6de0384
1:ed1b79f46b9a
$ hg pull
pulling from $TESTTMP/repo2 (glob)
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
(run 'hg update' to get a working copy)
$ hg heads -q --closed
4:00cfe9073916
2:effea6de0384
1:ed1b79f46b9a
$ cd ..
$ hg init copy
$ cd copy
Pull a missing revision:
$ hg pull -qr missing ../repo
abort: unknown revision 'missing'!
[255]
Pull multiple revisions with update:
$ hg pull -qu -r 0 -r 1 ../repo
$ hg -q parents
0:bbd179dfa0a7
$ hg rollback
repository tip rolled back to revision -1 (undo pull)
working directory now based on revision -1
$ hg pull -qr 0 ../repo
$ hg log
changeset: 0:bbd179dfa0a7
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ hg pull -qr 1 ../repo
$ hg log
changeset: 1:ed1b79f46b9a
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: change foo
changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
This used to abort: received changelog group is empty:
$ hg pull -qr 1 ../repo
Test race condition with -r and -U (issue4707)
We pull '-U -r <name>' and the name change right after/during the changegroup emission.
We use http because http is better is our racy-est option.
$ echo babar > ../repo/jungle
$ cat <<EOF > ../repo/.hg/hgrc
> [hooks]
> outgoing.makecommit = hg ci -Am 'racy commit'; echo committed in pull-race
> EOF
$ hg serve -R ../repo -p $HGPORT2 -d --pid-file=../repo.pid
$ cat ../repo.pid >> $DAEMON_PIDS
$ hg pull --rev default --update http://localhost:$HGPORT2/
pulling from http://localhost:$HGPORT2/
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log -G
@ changeset: 2:effea6de0384
| tag: tip
| parent: 0:bbd179dfa0a7
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: add bar
|
| o changeset: 1:ed1b79f46b9a
|/ user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: change foo
|
o changeset: 0:bbd179dfa0a7
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: add foo
$ cd ..