tests/test-narrow-patch.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

#testcases flat tree

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

#if tree
  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > treemanifest = 1
  > EOF
#endif

create full repo

  $ hg init master
  $ cd master

  $ mkdir inside
  $ echo inside > inside/f1
  $ mkdir outside
  $ echo outside > outside/f1
  $ hg ci -Aqm 'initial'

  $ echo modified > inside/f1
  $ hg ci -qm 'modify inside'

  $ echo modified > outside/f1
  $ hg ci -qm 'modify outside'

  $ cd ..

  $ hg clone --narrow ssh://user@dummy/master narrow --include inside
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 2 changes to 1 files
  new changesets *:* (glob)
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd narrow

Can show patch touching paths outside

  $ hg log -p
  changeset:   2:* (glob)
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify outside
  
  
  changeset:   1:* (glob)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     modify inside
  
  diff -r * -r * inside/f1 (glob)
  --- a/inside/f1	Thu Jan 01 00:00:00 1970 +0000
  +++ b/inside/f1	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -inside
  +modified
  
  changeset:   0:* (glob)
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     initial
  
  diff -r 000000000000 -r * inside/f1 (glob)
  --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
  +++ b/inside/f1	Thu Jan 01 00:00:00 1970 +0000
  @@ -0,0 +1,1 @@
  +inside
  

  $ hg status --rev 1 --rev 2

Can show copies inside the narrow clone

  $ hg cp inside/f1 inside/f2
  $ hg diff --git
  diff --git a/inside/f1 b/inside/f2
  copy from inside/f1
  copy to inside/f2