scmutil: create directories in a race-safe way during update
With the new parallel update code, it is possible for multiple
workers to try to create a hierarchy of directories at the same
time. This is hard to trigger in general, but most likely during
initial checkout.
To deal with these races, we introduce a new ensuredirs function
whose contract is to ensure that a directory hierarchy exists - it
will ignore a failure that implies that the desired directory already
exists.
$ cat >> $HGRCPATH <<EOF
> [extensions]
> graphlog=
> rebase=
>
> [phases]
> publish=False
>
> [alias]
> tglog = log -G --template "{rev}:{phase} '{desc}' {branches}\n"
> EOF
$ hg init a
$ cd a
$ echo A > A
$ hg add A
$ hg ci -m A
$ echo 'B' > B
$ hg add B
$ hg ci -m B
$ echo C >> A
$ hg ci -m C
$ hg up -q -C 0
$ echo D >> A
$ hg ci -m D
created new head
$ echo E > E
$ hg add E
$ hg ci -m E
$ hg up -q -C 0
$ hg branch 'notdefault'
marked working directory as branch notdefault
(branches are permanent and global, did you want a bookmark?)
$ echo F >> A
$ hg ci -m F
$ cd ..
Rebasing B onto E - check keep: and phases
$ hg clone -q -u . a a1
$ cd a1
$ hg phase --force --secret 2
$ hg tglog
@ 5:draft 'F' notdefault
|
| o 4:draft 'E'
| |
| o 3:draft 'D'
|/
| o 2:secret 'C'
| |
| o 1:draft 'B'
|/
o 0:draft 'A'
$ hg rebase -s 1 -d 4 --keep
merging A
warning: conflicts during merge.
merging A incomplete! (edit conflicts, then use 'hg resolve --mark')
abort: unresolved conflicts (see hg resolve, then hg rebase --continue)
[255]
Solve the conflict and go on:
$ echo 'conflict solved' > A
$ rm A.orig
$ hg resolve -m A
$ hg rebase --continue
$ hg tglog
@ 7:secret 'C'
|
o 6:draft 'B'
|
| o 5:draft 'F' notdefault
| |
o | 4:draft 'E'
| |
o | 3:draft 'D'
|/
| o 2:secret 'C'
| |
| o 1:draft 'B'
|/
o 0:draft 'A'
$ cd ..
Rebase F onto E - check keepbranches:
$ hg clone -q -u . a a2
$ cd a2
$ hg phase --force --secret 2
$ hg tglog
@ 5:draft 'F' notdefault
|
| o 4:draft 'E'
| |
| o 3:draft 'D'
|/
| o 2:secret 'C'
| |
| o 1:draft 'B'
|/
o 0:draft 'A'
$ hg rebase -s 5 -d 4 --keepbranches
merging A
warning: conflicts during merge.
merging A incomplete! (edit conflicts, then use 'hg resolve --mark')
abort: unresolved conflicts (see hg resolve, then hg rebase --continue)
[255]
Solve the conflict and go on:
$ echo 'conflict solved' > A
$ rm A.orig
$ hg resolve -m A
$ hg rebase --continue
saved backup bundle to $TESTTMP/a2/.hg/strip-backup/*-backup.hg (glob)
$ hg tglog
@ 5:draft 'F' notdefault
|
o 4:draft 'E'
|
o 3:draft 'D'
|
| o 2:secret 'C'
| |
| o 1:draft 'B'
|/
o 0:draft 'A'
$ cd ..