changelog: specify checkambig=True to avoid ambiguity around truncation
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 00changelog.i (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to 00changelog.i again
Therefore, cache validation doesn't work after (3) as expected.
To avoid such file stat ambiguity around truncation, this patch
specifies checkambig=True for renaming or opening to write changes out
at finalization.
Even after this patch, avoiding file stat ambiguity of 00changelog.i
around truncation isn't yet completed, because truncation side isn't
aware of this issue.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
.\" Hey, EMACS: -*- nroff -*-
.\" First parameter, NAME, should be all caps
.\" Second parameter, SECTION, should be 1-8, maybe w/ subsection
.\" other parameters are allowed: see man(7), man(1)
.TH CHG 1 "March 3, 2013"
.\" Please adjust this date whenever revising the manpage.
.\"
.\" Some roff macros, for reference:
.\" .nh disable hyphenation
.\" .hy enable hyphenation
.\" .ad l left justify
.\" .ad b justify to both left and right margins
.\" .nf disable filling
.\" .fi enable filling
.\" .br insert line break
.\" .sp <n> insert n+1 empty lines
.\" for manpage-specific macros, see man(7)
.SH NAME
chg \- a fast client for Mercurial command server
.SH SYNOPSIS
.B chg
.IR command " [" options "] [" arguments "]..."
.br
.SH DESCRIPTION
The
.B chg
command is the wrapper for
.B hg
command.
It uses the Mercurial command server to reduce start-up overhead.
.SH OPTIONS
This program accepts the same command line syntax as the
.B hg
command. Additionally it accepts the following options.
.TP
.B \-\-kill\-chg\-daemon
Terminate the background command servers.
.SH SEE ALSO
.BR hg (1),
.SH AUTHOR
Written by Yuya Nishihara <yuya@tcha.org>.