vfs: use checkambigatclosing in checkambig=True but atomictemp=False case
In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.
- writing changes out in revlog layer uses "a+" mode
- truncation in repair.strip() uses "a" mode
- truncation in transaction._playback() uses "a" mode
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
This patch uses checkambigatclosing in checkambig=True but
atomictemp=False case, to check (and get rid of) file stat ambiguity
at closing.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
This test file aims at test topological iteration and the various configuration it can has.
$ cat >> $HGRCPATH << EOF
> [ui]
> logtemplate={rev}\n
> EOF
On this simple example, all topological branch are displayed in turn until we
can finally display 0. this implies skipping from 8 to 3 and coming back to 7
later.
$ hg init test01
$ cd test01
$ hg unbundle $TESTDIR/bundles/remote.hg
adding changesets
adding manifests
adding file changes
added 9 changesets with 7 changes to 4 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg log -G
o 8
|
| o 7
| |
| o 6
| |
| o 5
| |
| o 4
| |
o | 3
| |
o | 2
| |
o | 1
|/
o 0
(display all nodes)
$ hg log -G -r 'sort(all(), topo)'
o 8
|
o 3
|
o 2
|
o 1
|
| o 7
| |
| o 6
| |
| o 5
| |
| o 4
|/
o 0
(revset skipping nodes)
$ hg log -G --rev 'sort(not (2+6), topo)'
o 8
|
o 3
:
o 1
|
| o 7
| :
| o 5
| |
| o 4
|/
o 0
(begin) from the other branch
$ hg log -G -r 'sort(all(), topo, topo.firstbranch=5)'
o 7
|
o 6
|
o 5
|
o 4
|
| o 8
| |
| o 3
| |
| o 2
| |
| o 1
|/
o 0