tests/test-obsolete-check-push.t

filemerge: add support for partial conflict resolution by external tool

A common class of merge conflicts is in imports/#includes/etc. It's
relatively easy to write a tool that can resolve these conflicts,
perhaps by naively just unioning the statements and leaving any
cleanup to other tools to do later [1]. Such specialized tools cannot
generally resolve all conflicts in a file, of course. Let's therefore
call them "partial merge tools". Note that the internal simplemerge
algorithm is such a partial merge tool - one that only resolves
trivial "conflicts" where one side is unchanged or both sides change
in the same way.

One can also imagine having smarter language-aware partial tools that
merge the AST. It may be useful for such tools to interactively let
the user resolve any conflicts it can't resolve itself. However,
having the option of implementing it as a partial merge tool means
that the developer doesn't *need* to create a UI for it. Instead, the
user can resolve any remaining conflicts with their regular merge tool
(e.g. `:merge3` or `meld).

We don't currently have a way to let the user define such partial
merge tools. That's what this patch addresses. It lets the user
configure partial merge tools to run. Each tool can be configured to
run only on files matching certain patterns (e.g. "*.py"). The tool
takes three inputs (local, base, other) and resolves conflicts by
updating these in place. For example, let's say the inputs are these:


base:
```
import sys

def main():
  print('Hello')
```

local:
```
import os
import sys

def main():
  print('Hi')
```

other:
```
import re
import sys

def main():
  print('Howdy')
```

A partial merge tool could now resolve the conflicting imports by
replacing the import statements in *all* files by the following
snippet, while leaving the remainder of the files unchanged.

```
import os
import re
import sys
```

As a result, simplemerge and any regular merge tool that runs after
the partial merge tool(s) will consider the imports to be
non-conflicting and will only present the conflict in `main()` to the
user.

Differential Revision: https://phab.mercurial-scm.org/D12356

=======================================================
Test check for obsolescence and instability during push
=======================================================

  $ . $TESTDIR/testlib/obsmarker-common.sh

  $ cat >> $HGRCPATH << EOF
  > [phases]
  > publish=false
  > [experimental]
  > evolution = all
  > EOF


Tests that pushing orphaness to the server is detected
======================================================

initial setup

  $ mkdir base
  $ cd base
  $ hg init server
  $ cd server
  $ mkcommit root
  $ hg phase --public .
  $ mkcommit commit_A0_
  $ mkcommit commit_B0_
  $ cd ..
  $ hg init client
  $ cd client
  $ echo '[paths]' >> .hg/hgrc
  $ echo 'default=../server' >> .hg/hgrc
  $ hg pull
  pulling from $TESTTMP/base/server
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files
  new changesets 1e4be0697311:c09d8ab29fda (2 drafts)
  (run 'hg update' to get a working copy)
  $ hg up 'desc("root")'
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(having some unrelated change affects discovery result, we should ideally test both case)
  $ hg branch unrelated --quiet
  $ mkcommit unrelated
  $ hg up null
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg log -G
  o  changeset:   3:16affbe0f986
  |  branch:      unrelated
  |  tag:         tip
  |  parent:      0:1e4be0697311
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unrelated
  |
  | o  changeset:   2:c09d8ab29fda
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  summary:     commit_B0_
  | |
  | o  changeset:   1:37624bf21024
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     commit_A0_
  |
  o  changeset:   0:1e4be0697311
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  
  $ cd ..
  $ cd ..


Orphan from pruning
-------------------

Setup

  $ cp -R base check-pruned
  $ cd check-pruned/client
  $ hg debugobsolete --record-parents `getid 'desc("commit_A0_")'`
  1 new obsolescence markers
  obsoleted 1 changesets
  1 new orphan changesets
  $ hg log -G
  o  changeset:   3:16affbe0f986
  |  branch:      unrelated
  |  tag:         tip
  |  parent:      0:1e4be0697311
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     unrelated
  |
  | *  changeset:   2:c09d8ab29fda
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  instability: orphan
  | |  summary:     commit_B0_
  | |
  | x  changeset:   1:37624bf21024
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    obsolete:    pruned
  |    summary:     commit_A0_
  |
  o  changeset:   0:1e4be0697311
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  

Pushing the result is prevented with a message

  $ hg push --new-branch
  pushing to $TESTTMP/check-pruned/server
  searching for changes
  abort: push includes orphan changeset: c09d8ab29fda!
  [255]

  $ cd ../..


Orphan from superseding
-----------------------

Setup

  $ cp -R base check-superseded
  $ cd check-superseded/client
  $ hg up 'desc("commit_A0_")'
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch other
  marked working directory as branch other
  $ hg commit --amend -m commit_A1_
  1 new orphan changesets
  $ hg log -G
  @  changeset:   4:df9b82a99e21
  |  branch:      other
  |  tag:         tip
  |  parent:      0:1e4be0697311
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     commit_A1_
  |
  | o  changeset:   3:16affbe0f986
  |/   branch:      unrelated
  |    parent:      0:1e4be0697311
  |    user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     unrelated
  |
  | *  changeset:   2:c09d8ab29fda
  | |  user:        test
  | |  date:        Thu Jan 01 00:00:00 1970 +0000
  | |  instability: orphan
  | |  summary:     commit_B0_
  | |
  | x  changeset:   1:37624bf21024
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    obsolete:    rewritten using amend as 4:df9b82a99e21
  |    summary:     commit_A0_
  |
  o  changeset:   0:1e4be0697311
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     root
  

Pushing the result is prevented with a message

  $ hg push --new-branch
  pushing to $TESTTMP/check-superseded/server
  searching for changes
  abort: push includes orphan changeset: c09d8ab29fda!
  [255]

  $ cd ../..

Tests that user get warned if it is about to publish obsolete/unstable content
------------------------------------------------------------------------------

Orphan from pruning
-------------------

Make sure the only difference is phase:

  $ cd check-pruned/client
  $ hg push --force --rev 'not desc("unrelated")'
  pushing to $TESTTMP/check-pruned/server
  searching for changes
  no changes found
  1 new obsolescence markers
  obsoleted 1 changesets
  1 new orphan changesets
  [1]

Check something prevents a silent publication of the obsolete changeset

  $ hg push --publish --new-branch
  pushing to $TESTTMP/check-pruned/server
  searching for changes
  abort: push includes orphan changeset: c09d8ab29fda!
  [255]

  $ cd ../..

Orphan from superseding
-----------------------

Make sure the only difference is phase:

  $ cd check-superseded/client
  $ hg push --force --rev 'not desc("unrelated")'
  pushing to $TESTTMP/check-superseded/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  1 new obsolescence markers
  obsoleted 1 changesets
  1 new orphan changesets

Check something prevents a silent publication of the obsolete changeset

  $ hg push --publish --new-branch
  pushing to $TESTTMP/check-superseded/server
  searching for changes
  abort: push includes orphan changeset: c09d8ab29fda!
  [255]

  $ cd ../..