atomicupdate: add an experimental option to use atomictemp when updating
In some cases Mercurial truncating files when updating causes problems. It can
happens when processes are currently reading the file or with big file or on
NFS mounts.
We add an experimental option to use the atomictemp option of vfs.__call__ in
order to avoid the problem.
The localrepository.wwrite seems to assume the files are created without the
`x` flag; with atomictempfile, the new file might inherit the `x` flag from
the destination. We force remove it afterward. This code could be refactored
and the flag processing could be moved inside vfs.
This patch should be tested with
`--extra-config-opt experimental.update.atomic-file=True`
as we disabled the option by default.
Differential Revision: https://phab.mercurial-scm.org/D1882
$ 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 b
merging a failed!
merging b failed!
unresolved conflicts (see hg resolve, then hg rebase --continue)
[1]
$ 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 b
merging a failed!
merge halted after failed merge (see hg resolve)
[1]
$ 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 b
merging a failed!
continue merge operation (yn)? y
merging b failed!
continue merge operation (yn)? n
merge halted after failed merge (see hg resolve)
[1]
$ 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
merging b
output file a appears unchanged
was merge successful (yn)? y
output file b appears unchanged
was merge successful (yn)? n
merging b failed!
continue merge operation (yn)? n
merge halted after failed merge (see hg resolve)
[1]
$ 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 b
merging a failed!
merge halted after failed merge (see hg resolve)
[1]
$ 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
merging b
was merge of 'a' successful (yn)? y
was merge of 'b' successful (yn)? n
merging b failed!
merge halted after failed merge (see hg resolve)
[1]
$ 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
merging b
$TESTTMP/repo/a *a~base* *a~other* (glob)
$TESTTMP/repo/b *b~base* *b~other* (glob)