tests/test-chainsaw-update.t

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

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

Two things worth pointing out-

  1) The `cffi` module "inherits" the `pure` implementation of `patchedsize()`
     because of its wildcard import.
  2) It's odd that the `mpatchError` lives in both `pure` and `cext` modules.

I initially thought to move the exception into the new class, and make the
existing class name an alias to the class in the new location, but the exception
is created in C code by the `cext` module, so that won't work.  I don't think a
protocol class is approriate, because there's nothing special about the class to
distinguish from any other `Exception`.  Fortunately, nobody is catching this
exception in core, so we can kick the can down the road.

============================================
Tests for the admin::chainsaw-update command
============================================

setup
=====

  $ hg init src
  $ cd src
  $ echo 1 > root
  $ hg add root
  $ hg ci -Am R_0
  $ hg branch A
  marked working directory as branch A
  (branches are permanent and global, did you want a bookmark?)
  $ echo 42 > bar
  $ hg add bar
  $ hg ci -Am A_0
  $ echo 1337 > bar
  $ hg ci -Am A_1
  $ hg update 'desc(R_0)'
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo 1 > foo
  $ hg add foo
  $ hg ci -Am B_0
  $ hg log -G
  @  changeset:   3:bfcb8e629987
  |  tag:         tip
  |  parent:      0:06f48e4098b8
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     B_0
  |
  | o  changeset:   2:7fd8de258aa4
  | |  branch:      A
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     A_1
  | |
  | o  changeset:   1:ae1692b8aadb
  |/   branch:      A
  |    user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     A_0
  |
  o  changeset:   0:06f48e4098b8
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     R_0
  
  $ cd ..

Actual tests
============

Initial cloning if needed
-------------------------

  $ hg admin::chainsaw-update --dest repo --rev default --source ./src
  no such directory: "repo"
  creating repository at "repo"
  recovering after interrupted transaction, if any
  no interrupted transaction available
  pulling from ./src
  updating to revision 'default'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  chainsaw-update to revision 'default' for repository at '$TESTTMP/repo' done

  $ cd repo
  $ hg log -G
  @  changeset:   3:bfcb8e629987
  |  tag:         tip
  |  parent:      0:06f48e4098b8
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     B_0
  |
  | o  changeset:   2:7fd8de258aa4
  | |  branch:      A
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     A_1
  | |
  | o  changeset:   1:ae1692b8aadb
  |/   branch:      A
  |    user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     A_0
  |
  o  changeset:   0:06f48e4098b8
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     R_0
  
  $ hg status -A
  C foo
  C root
  $ cat foo
  1

Test lock breacking capabilities
--------------------------------

Demonstrate lock-breaking capabilities with locks that regular Mercurial
operation would not break, because the hostnames registered in locks differ
from the current hostname (happens a lot with succesive containers):

#if symlink
  $ ln -s invalid.host.test/effffffc:171814 .hg/store/lock
  $ ln -s invalid.host.test/effffffc:171814 .hg/wlock
#else
  $ printf 'invalid.host.test/effffffc:171814' > .hg/store/lock
  $ printf 'invalid.host.test/effffffc:171814' > .hg/wlock
#endif
  $ hg debuglock
  lock:  (.*?), process 171814, host invalid.host.test/effffffc \((\d+)s\) (re)
  wlock: (.*?), process 171814, host invalid.host.test/effffffc \((\d+)s\) (re)
  [2]

  $ hg admin::chainsaw-update --no-purge-ignored --dest . --rev default --source ../src
  loaded repository at "."
  had to break store lock
  had to break working copy lock
  recovering after interrupted transaction, if any
  no interrupted transaction available
  pulling from ../src
  updating to revision 'default'
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  chainsaw-update to revision 'default' for repository at '$TESTTMP/repo' done

Test file purging capabilities
------------------------------

Let's also add local modifications (tracked and untracked) to demonstrate the
purging.

  $ echo untracked > bar
  $ echo modified > foo
  $ hg status -A
  M foo
  ? bar
  C root

  $ echo 2 > ../src/foo
  $ hg -R ../src commit -mB_1
  $ hg admin::chainsaw-update --dest . --rev default --source ../src -q
  no interrupted transaction available
  $ hg log -G
  @  changeset:   4:973ab81c95fb
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     B_1
  |
  o  changeset:   3:bfcb8e629987
  |  parent:      0:06f48e4098b8
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     B_0
  |
  | o  changeset:   2:7fd8de258aa4
  | |  branch:      A
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     A_1
  | |
  | o  changeset:   1:ae1692b8aadb
  |/   branch:      A
  |    user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     A_0
  |
  o  changeset:   0:06f48e4098b8
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     R_0
  
  $ hg status -A
  C foo
  C root
  $ cat foo
  2

Now behaviour with respect to ignored files: they are not purged if
the --no-purge-ignored flag is passed, but they are purged by default

  $ echo bar > .hgignore
  $ hg ci -Aqm hgignore
  $ echo ignored > bar
  $ hg status --all
  I bar
  C .hgignore
  C foo
  C root

  $ hg admin::chainsaw-update --no-purge-ignored --dest . --rev default --source ../src -q
  no interrupted transaction available
  $ hg status --all
  I bar
  C .hgignore
  C foo
  C root
  $ cat bar
  ignored

  $ hg admin::chainsaw-update --dest . --rev default --source ../src -q
  no interrupted transaction available
  $ hg status --all
  C .hgignore
  C foo
  C root
  $ test -f bar
  [1]

test --minimal-initial-cloning variant
--------------------------------------

With `--minimal-initial-cloning`, there is no "requesting all changes"
message. Hence clone bundles would be bypassed (TODO test both cases
# with an actual clone-bundle)

  $ cd ..
  $ hg admin::chainsaw-update --dest repo2 --rev default --source src --initial-clone-minimal
  no such directory: "repo2"
  creating repository at "repo2"
  recovering after interrupted transaction, if any
  no interrupted transaction available
  pulling from src
  updating to revision 'default'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  chainsaw-update to revision 'default' for repository at '$TESTTMP/repo2' done

  $ cd repo2
  $ hg log -G
  @  changeset:   2:973ab81c95fb
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     B_1
  |
  o  changeset:   1:bfcb8e629987
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     B_0
  |
  o  changeset:   0:06f48e4098b8
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     R_0
  
  $ hg status -A
  C foo
  C root
  $ cat foo
  2