localrepo: stop doing special dirstate backup at transaction open
Since the dirstate writes are already managed by the transaction, we already do
a backup of the dirstate when necessary (and even trigger one to keep `hg
rollback` happy).
We needs some special code to deal with the initial empty checkout, but it is
not too complicated.
Managing variable filename (as dirstate-v2 uses) at the "journalfile" level, is
complex and fragile (which is consistent with the fact these files are not
journal…). If we no longer do it, our life is significantly simpler.
In some sense, we apply the xkcd-1134¹ solution to our savebackup/restorebackup
problem.
[1] https://xkcd.com/1134/
(the change to test-hardlink are expect as decreasing the number of duplicated
backup drive the hardlink count down)
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase=
> [phases]
> publish=False
> [merge]
> EOF
$ hg init repo
$ cd repo
$ echo a > a
$ echo b > b
$ hg commit -qAm ab
$ echo c >> a
$ echo c >> b
$ hg commit -qAm c
$ hg up -q ".^"
$ echo d >> a
$ echo d >> b
$ hg commit -qAm d
Testing on-failure=continue
$ echo on-failure=continue >> $HGRCPATH
$ hg rebase -s 1 -d 2 --tool false
rebasing 1:1f28a51c3c9b "c"
merging a
merging a failed!
merging b
merging b failed!
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Testing on-failure=halt
$ echo on-failure=halt >> $HGRCPATH
$ hg rebase -s 1 -d 2 --tool false
rebasing 1:1f28a51c3c9b "c"
merging a
merging a failed!
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Testing on-failure=prompt
$ cat <<EOS >> $HGRCPATH
> [merge]
> on-failure=prompt
> [ui]
> interactive=1
> EOS
$ cat <<EOS | hg rebase -s 1 -d 2 --tool false
> y
> n
> EOS
rebasing 1:1f28a51c3c9b "c"
merging a
merging a failed!
continue merge operation (yn)? y
merging b
merging b failed!
continue merge operation (yn)? n
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Check that successful tool with failed post-check halts the merge
$ cat <<EOS >> $HGRCPATH
> [merge-tools]
> true.check=changed
> EOS
$ cat <<EOS | hg rebase -s 1 -d 2 --tool true
> y
> n
> n
> EOS
rebasing 1:1f28a51c3c9b "c"
merging a
output file a appears unchanged
was merge successful (yn)? y
merging b
output file b appears unchanged
was merge successful (yn)? n
merging b failed!
continue merge operation (yn)? n
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg resolve --list
R a
U b
$ hg rebase --abort
rebase aborted
Check that conflicts with conflict check also halts the merge
$ cat <<EOS >> $HGRCPATH
> [merge-tools]
> true.check=conflicts
> true.premerge=keep
> [merge]
> on-failure=halt
> EOS
$ hg rebase -s 1 -d 2 --tool true
rebasing 1:1f28a51c3c9b "c"
merging a
merging a failed!
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg resolve --list
U a
U b
$ hg rebase --abort
rebase aborted
Check that always-prompt also can halt the merge
$ cat <<EOS | hg rebase -s 1 -d 2 --tool true --config merge-tools.true.check=prompt
> y
> n
> EOS
rebasing 1:1f28a51c3c9b "c"
merging a
was merge of 'a' successful (yn)? y
merging b
was merge of 'b' successful (yn)? n
merging b failed!
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ hg resolve --list
R a
U b
$ hg rebase --abort
rebase aborted
Check that successful tool otherwise allows the merge to continue
$ hg rebase -s 1 -d 2 --tool echo --keep --config merge-tools.echo.premerge=keep
rebasing 1:1f28a51c3c9b "c"
merging a
$TESTTMP/repo/a *a~base* *a~other* (glob)
merging b
$TESTTMP/repo/b *b~base* *b~other* (glob)
Check that unshelve isn't broken by halting the merge
$ cat <<EOS >> $HGRCPATH
> [extensions]
> shelve =
> [merge-tools]
> false.check=conflicts
> false.premerge=false
> EOS
$ echo foo > shelve_file1
$ echo foo > shelve_file2
$ hg ci -qAm foo
$ echo bar >> shelve_file1
$ echo bar >> shelve_file2
$ hg shelve --list
$ hg shelve
shelved as default
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo baz >> shelve_file1
$ echo baz >> shelve_file2
$ hg ci -m baz
$ hg unshelve --tool false --config merge-tools.false.premerge=keep
unshelving change 'default'
rebasing shelved changes
merging shelve_file1
merging shelve_file1 failed!
unresolved conflicts (see 'hg resolve', then 'hg unshelve --continue')
[240]
$ hg status --config commands.status.verbose=True
M shelve_file1
M shelve_file2
? shelve_file1.orig
# The repository is in an unfinished *unshelve* state.
# Unresolved merge conflicts:
#
# shelve_file1
# shelve_file2
#
# To mark files as resolved: hg resolve --mark FILE
# To continue: hg unshelve --continue
# To abort: hg unshelve --abort
$ hg resolve --tool false --all --re-merge
merging shelve_file1
merging shelve_file1 failed!
merge halted after failed merge (see hg resolve)
[240]
$ hg shelve --list
default (*s ago) * changes to: foo (glob)
$ hg unshelve --abort
unshelve of 'default' aborted