tests/test-remotefilelog-bundle2.t

rhg: Port Python’s `ui.configlist` as `Config::get_list`

This new method is not used yet outside of its own unit tests,
so this changeset should make no observable change.

The Rust parser implementation attempts to exactly replicate the behavior of
the Python one, even in edge cases where that behavior is… surprising.
New unit tests capture some of these edge cases.

This started as a line-by-line port. The main changes are:

* Pass around a parser mode enum instead of parser functions
* Inline the whole parser into one function
* Use `[u8]::get` which returns an `Option`,
  instead of indexing  after explicitly checking the length.

Differential Revision: https://phab.mercurial-scm.org/D11389

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"

  $ hg init master
  $ grep generaldelta master/.hg/requires
  generaldelta
  $ cd master
preferuncompressed = False so that we can make both generaldelta and non-generaldelta clones
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > [experimental]
  > bundle2-exp = True
  > [server]
  > preferuncompressed = False
  > EOF
  $ echo x > x
  $ hg commit -qAm x

  $ cd ..

  $ hgcloneshallow ssh://user@dummy/master shallow-generaldelta -q --pull --config experimental.bundle2-exp=True
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
  $ grep generaldelta shallow-generaldelta/.hg/requires
  generaldelta
  $ hgcloneshallow ssh://user@dummy/master shallow-plain -q --pull --config format.usegeneraldelta=False --config format.generaldelta=False --config experimental.bundle2-exp=True
  $ grep generaldelta shallow-plain/.hg/requires
  [1]

  $ cd master
  $ echo a > a
  $ hg commit -qAm a

pull from generaldelta to generaldelta
  $ cd ../shallow-generaldelta
  $ hg pull -u
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files
  new changesets 2fbb8bb2b903
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
push from generaldelta to generaldelta
  $ echo b > b
  $ hg commit -qAm b
  $ hg push
  pushing to ssh://user@dummy/master
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
pull from generaldelta to non-generaldelta
  $ cd ../shallow-plain
  $ hg pull -u
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 0 changes to 0 files
  new changesets 2fbb8bb2b903:d6788bd632ca
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  1 files fetched over 1 fetches - (1 misses, 0.00% hit ratio) over *s (glob)
push from non-generaldelta to generaldelta
  $ echo c > c
  $ hg commit -qAm c
  $ hg push
  pushing to ssh://user@dummy/master
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files