shelve: keep old backups if timestamp can't decide exact order of them
Before this patch, backups to be discarded are decided by steps below
at 'hg unshelve' or so:
1. list '(st_mtime, filename)' tuples of each backups up
2. sort list of these tuples, and
3. discard backups other than 'maxbackups' ones at the end of list
This doesn't work well in the case below:
- "sort by name" order differs from actual backup-ing order, and
- some of backups have same timestamp
For example, 'test-shelve.t' satisfies the former condition:
- 'default-01' < 'default-1' in "sort by name" order
- 'default-1' < 'default-01' in actual backup-ing order
Then, 'default-01' is discarded instead of 'default-1' unexpectedly,
if they have same timestamp. This failure appears occasionally,
because the most important condition "same timestamp" is timing
critical.
To avoid such unexpected discarding, this patch keeps old backups if
timestamp can't decide exact order of them.
Timestamp of the border backup (= the oldest one of recent
'maxbackups' ones) as 'bordermtime' is used to examine whether
timestamp can decide exact order of backups.
syntax: glob
*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
tests/.coverage*
tests/annotated
tests/*.err
tests/htmlcov
build
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.idea/*
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py
# files installed with a local --pure build
mercurial/base85.py
mercurial/bdiff.py
mercurial/diffhelpers.py
mercurial/mpatch.py
mercurial/osutil.py
mercurial/parsers.py
syntax: regexp
^\.pc/
^\.(pydev)?project
# hackable windows distribution additions
^hg-python
^hg.py$