view contrib/plan9/README @ 21932:21a2f31f054d stable

largefiles: use "normallookup", if "mtime" of standin is unset

Before this patch, largefiles gotten from "other" revision (without
conflict) at "hg merge" become "clean" unexpectedly in steps below:

    1. "merge.update()" is invoked
      1-1 standinfile SF is updated in the working directory
      1-2 "dirstate" entry for SF is "normallookup"-ed

    2. "lfcommands.updatelfiles()" is invoked (by "overrides.hgmerge()")
      2-1 largefile LF (for SF) is updated in the working directory
      2-2 "dirstate" returns "n" for SF (by 1-2)
      2-3 "lfdirstate" entry for LF is "normal"-ed
      2-4 "lfdirstate" is written into ".hg/largefiles/dirstate", and
          timestamp of LF is stored into "lfdirstate" file
          (ASSUMPTION: timestamp of LF differs from one of "lfdirstate" file)

Then, "hs status" treats LF as "clean", even though LF is updated by
"other" revision (by 2-1), because "lfilesrepo.status()" always treats
"normal"-ed files (by 2-3 and 2-4) as "clean".

When timestamp is not set (= negative value) for standinfile in
"dirstate", largefile should be "normallookup"-ed regardless of
rebasing or not, because "n" state in "dirstate" doesn't ensure
"clean"-ness of a standinfile at that time.

This patch uses "normallookup" instead of "normal", if "mtime" of
standin is unset

This is a temporary way to fix with less changes. For fundamental
resolution of this kind of problems in the future, "lfdirstate" should
be updated with "dirstate" simultaneously while "merge.update"
execution: maybe by hooking "recordupdates"

It is also why this patch (temporarily) uses internal field "_map" of
"dirstate" directly.

This patch uses "[debug] dirstate.delaywrite" feature in the test, to
ensure that timestamp of the largefile gotten from "other" revision is
stored into ".hg/largefiles/dirstate". (for ASSUMPTION at 2-4)

This patch newly adds "test-largefiles-update.t", to avoid increasing
cost to run other tests for largefiles by subsequent patches
(especially, "[debug] dirstate.delaywrite" causes so).

Mercurial for Plan 9 from Bell Labs
===================================

This directory contains support for Mercurial on Plan 9 from Bell Labs
platforms. It is assumed that the version of Python running on these
systems supports the ANSI/POSIX Environment (APE). At the time of this
writing, the bichued/python port is the most commonly installed version
of Python on these platforms. If a native port of Python is ever made,
some minor modification will need to be made to support some of the more
esoteric requirements of the platform rather than those currently made
(cf. posix.py).

By default, installations will have the factotum extension enabled; this
extension permits factotum(4) to act as an authentication agent for
HTTP repositories. Additionally, an extdiff command named 9diff is
enabled which generates diff(1) compatible output suitable for use with
the plumber(4).

Commit messages are plumbed using E if no editor is defined; users must
update the plumbed file to continue, otherwise the hg process must be
interrupted.

Some work remains with regard to documentation. Section 5 manual page
references for hgignore and hgrc need to be re-numbered to section 6 (file
formats) and a new man page writer should be written to support the
Plan 9 man macro set. Until these issues can be resolved, manual pages
are elided from the installation.

Basic install:

  % mk install      # do a system-wide install
  % hg debuginstall # sanity-check setup
  % hg              # see help

A proto(2) file is included in this directory as an example of how a
binary distribution could be packaged, ostensibly with contrib(1).

See http://mercurial.selenic.com/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.