tests/test-import-merge.t

interfaces: introduce and use a protocol class for the `charencoding` module

See f2832de2a46c for details when this was done for the `bdiff` module.

This lets us dump the hack where the `pure` implementation was imported during
the type checking phase to provide signatures for the module methods it
provides.  Now the protocol classes are starting to shine, because these methods
are provided by `pure.charencoding` and `cext.parsers`, and references to
`cffi.charencoding` and `cext.charencoding` are forwarded to them as appropriate
by the `policy` module.  But none of that matters, as long as the module
returned provides the listed methods.

The interface was copy/pasted from the `pure` module, but `jsonescapeu8fallback`
is omitted because it is accessed from the `pure` module directly when the
escaping fails in the primary module's `jsonescapeu8()`.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ tipparents() {
  > hg parents --template "{rev}:{node|short} {desc|firstline}\n" -r tip
  > }

Test import and merge diffs

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ hg ci -Am adda
  adding a
  $ echo a >> a
  $ hg ci -m changea
  $ echo c > c
  $ hg ci -Am addc
  adding c
  $ hg up 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo b > b
  $ hg ci -Am addb
  adding b
  created new head
  $ hg up 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m merge
  $ hg export . > ../merge.diff
  $ grep -v '^merge$' ../merge.diff > ../merge.nomsg.diff
  $ cd ..
  $ hg clone -r2 repo repo2
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 2 files
  new changesets 07f494440405:890ecaa90481
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd repo2
  $ hg pull -r3 ../repo
  pulling from ../repo
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  new changesets 102a90ea7b4a
  (run 'hg heads' to see heads, 'hg merge' to merge)

Test without --exact and diff.p1 == workingdir.p1

  $ hg up 1
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ cat > $TESTTMP/editor.sh <<EOF
  > env | grep HGEDITFORM
  > echo merge > \$1
  > EOF
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg import --edit ../merge.nomsg.diff
  applying ../merge.nomsg.diff
  HGEDITFORM=import.normal.merge
  $ tipparents
  1:540395c44225 changea
  3:102a90ea7b4a addb
  $ hg strip --no-backup tip
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

Test without --exact and diff.p1 != workingdir.p1

  $ hg up 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg import ../merge.diff
  applying ../merge.diff
  warning: import the patch as a normal revision
  (use --exact to import the patch as a merge)
  $ tipparents
  2:890ecaa90481 addc
  $ hg strip --no-backup tip
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

Test with --exact

  $ hg import --exact ../merge.diff
  applying ../merge.diff
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ tipparents
  1:540395c44225 changea
  3:102a90ea7b4a addb
  $ hg strip --no-backup tip
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

Test with --bypass and diff.p1 == workingdir.p1

  $ hg up 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg import --bypass ../merge.diff
  applying ../merge.diff
  $ tipparents
  1:540395c44225 changea
  3:102a90ea7b4a addb
  $ hg strip --no-backup tip

Test with --bypass and diff.p1 != workingdir.p1

  $ hg up 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg import --bypass ../merge.diff
  applying ../merge.diff
  warning: import the patch as a normal revision
  (use --exact to import the patch as a merge)
  $ tipparents
  2:890ecaa90481 addc
  $ hg strip --no-backup tip

Test with --bypass and --exact

  $ hg import --bypass --exact ../merge.diff
  applying ../merge.diff
  $ tipparents
  1:540395c44225 changea
  3:102a90ea7b4a addb
  $ hg strip --no-backup tip

  $ cd ..

Test that --exact on a bad header doesn't corrupt the repo (issue3616)

  $ hg init repo3
  $ cd repo3
  $ echo a>a
  $ hg ci -Aqm0
  $ echo a>>a
  $ hg ci -m1
  $ echo a>>a
  $ hg ci -m2
  $ echo a>a
  $ echo b>>a
  $ echo a>>a
  $ hg ci -m3
  $ hg export 2 | head -7 > ../a.patch
  $ hg export tip > out
  >>> apatch = open("../a.patch", "ab")
  >>> apatch.write(b"".join(open("out", 'rb').readlines()[7:])) and None

  $ cd ..
  $ hg clone -qr0 repo3 repo3-clone
  $ cd repo3-clone
  $ hg pull -qr1 ../repo3

  $ hg import --exact ../a.patch
  applying ../a.patch
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  patching file a
  Hunk #1 succeeded at 1 with fuzz 1 (offset -1 lines).
  transaction abort!
  rollback completed
  abort: patch is damaged or loses information
  [255]
  $ hg verify -q