phabricator: use Phabricator's last node information
This makes it more strict when checking whether or not we should update a
Differential Revision. For example,
a) Alice updates D1 to content 1.
b) Bob updates D1 to content 2.
c) Alice tries to update D1 to content 1.
Previously, `c)` will do nothing because `phabsend` detects the patch is not
changed. A more correct behavior is to override Bob's update here, hence the
patch.
This also makes it possible to return a reaonsable "last node" when there is
no tags but only `Differential Revision` commit messages.
Test Plan:
```
for i in A B C; do echo $i > $i; hg ci -m $i -A $i; done
hg phabsend 0::
# D40: created
# D41: created
# D42: created
echo 3 >> C; hg amend; hg phabsend .
# D42: updated
hg tag --local --hidden -r 2 -f D42
# move tag to the previous version
hg phabsend .
# D42: skipped (previously it would be "updated")
rm -rf .hg; hg init
hg phabread --stack D42 | hg import -
hg phabsend .
# D42: updated
hg tag --local --remove D42
hg commit --amend
hg phabsend .
# D42: updated (no new diff uploaded, previously it will upload a new diff)
```
The old diff object is now returned, which could be useful in the next
patch.
Differential Revision: https://phab.mercurial-scm.org/D121
Test hg log changeset printer external hook
-------------------------------------------
$ cat > $TESTTMP/logexthook.py <<EOF
> from mercurial import repair, commands
> from mercurial import cmdutil
> def rot13description(self, ctx):
> summary = "summary".encode('rot13')
> description = ctx.description().strip().splitlines()[0].encode('rot13')
> self.ui.write("%s: %s\n" % (summary, description))
> def reposetup(ui, repo):
> cmdutil.changeset_printer._exthook = rot13description
> EOF
Prepare the repository
$ hg init empty
$ cd empty
$ touch ROOT
$ hg commit -A -m "Root" ROOT
$ touch a b c
$ hg commit -A -m "Add A, B, C" a b c
Check the log
$ hg log --config extensions.t=$TESTTMP/logexthook.py
changeset: 1:70fc82b23320
tag: tip
user: test
date: Thu Jan 01 00:00:00 1970 +0000
fhzznel: Nqq N, O, P
summary: Add A, B, C
changeset: 0:b00443a54871
user: test
date: Thu Jan 01 00:00:00 1970 +0000
fhzznel: Ebbg
summary: Root
Check that exthook is working with graph log too
$ hg log -G --config extensions.t=$TESTTMP/logexthook.py
@ changeset: 1:70fc82b23320
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| fhzznel: Nqq N, O, P
| summary: Add A, B, C
|
o changeset: 0:b00443a54871
user: test
date: Thu Jan 01 00:00:00 1970 +0000
fhzznel: Ebbg
summary: Root