tests/test-strip-branch-cache.t

dispatch: change cwd when loading local config

Previously, the `_getlocal` function would not correctly load the repo config
when given a relative `rpath` and an alternate cwd via the `wd` parameter.

Normally when `--cwd` is specified, hg changes to the given directory before
attempting to load the local config (and therefore does not specify a `wd`).
The only time the function is called with `wd` set is when hg is running as a
command server (e.g., with chg), in which case each forked worker process will
attempt to configure itself via `_getlocal` before responding to the client.
When given a relative repo path, the worker fails to load the repo config,
detects a config mismatch with the client, and enters a redirect/respawn loop.

To fix this, we can simply change to the desired working directory during
config loading. (Note that simply concatenating `wd` and `rpath` won't work
in all cases. The repo path could be something more complicated than a simple
relative path, such as a `union:` repo.)

Define helpers.

  $ hg_log () { hg log -G -T "{rev}:{node|short}"; }
  $ commit () { echo "foo - ${2:-$1}" > $1; hg commit -Aqm "Edited $1"; }
  $ strip() { hg --config extensions.strip= strip -q -r "$1" ; }

Setup hg repo.

  $ hg init repo
  $ cd repo
  $ touch x; hg add x; hg commit -m "initial"
  $ hg clone -q . ../clone
  $ commit a

  $ cd ../clone

  $ commit b

  $ hg pull -q ../repo

  $ cat .hg/cache/branch2-visible
  222ae9789a75703f9836e44de7db179cbfd420ee 2
  a3498d6e39376d2456425dd8c692367bdbf00fa2 o default
  222ae9789a75703f9836e44de7db179cbfd420ee o default

  $ hg_log
  o  2:222ae9789a75
  |
  | @  1:a3498d6e3937
  |/
  o  0:7ab0a3bd758a
  

  $ strip '1:'

The branchmap cache is not adjusted on strip.
Now mentions a changelog entry that has been stripped.

  $ cat .hg/cache/branch2-visible
  222ae9789a75703f9836e44de7db179cbfd420ee 2
  a3498d6e39376d2456425dd8c692367bdbf00fa2 o default
  222ae9789a75703f9836e44de7db179cbfd420ee o default

  $ commit c

Not adjusted on commit, either.

  $ cat .hg/cache/branch2-visible
  222ae9789a75703f9836e44de7db179cbfd420ee 2
  a3498d6e39376d2456425dd8c692367bdbf00fa2 o default
  222ae9789a75703f9836e44de7db179cbfd420ee o default

On pull we end up with the same tip, and so wrongly reuse the invalid cache and crash.

  $ hg pull ../repo 2>&1 | grep 'ValueError:'
  ValueError: node a3498d6e39376d2456425dd8c692367bdbf00fa2 does not exist (known-bad-output !)