view tests/test-empty-group.t @ 25732:b94df10cc3b5

hghave: allow adding customized features at runtime

Before this patch, there is no way to add customized features to
`hghave` without changing `hghave` and `hghave.py` themselves.

This decreases reusability of `run-tests.py` framework for third party
tools, because they may want to examine custom features at runtime
(e.g.  existence of some external tools).

To allow adding customized features at runtime, this patch makes
`hghave` import `hghaveaddon` module, only when `hghaveaddon.py` file
can be found in directories below:

  - `TESTDIR` for invocation via `run-tests.py`
  - `.` for invocation via command line

The path to the directory where `hghaveaddon.py` should be placed is
added to `sys.path` only while importing `hghaveaddon`, because:

  - `.` may not be added to `PYTHONPATH`

  - adding additional path to `sys.path` may change behavior of
    subsequent `import` for other features

`hghave` is terminated with exit code '2' at failure of `import
hghaveaddon`, because exit code '2' terminates `run-tests.py`
immediately.

This is a one of preparations for issue4677.

#  A          B
#
#  3  4       3
#  |\/|       |\
#  |/\|       | \
#  1  2       1  2
#  \ /        \ /
#   0          0
#
# if the result of the merge of 1 and 2
# is the same in 3 and 4, no new manifest
# will be created and the manifest group
# will be empty during the pull
#
# (plus we test a failure where outgoing
# wrongly reported the number of csets)

  $ hg init a
  $ cd a
  $ touch init
  $ hg ci -A -m 0
  adding init
  $ touch x y
  $ hg ci -A -m 1
  adding x
  adding y

  $ hg update 0
  0 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ touch x y
  $ hg ci -A -m 2
  adding x
  adding y
  created new head

  $ hg merge 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -A -m m1

  $ hg update -C 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg merge 2
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -A -m m2
  created new head

  $ cd ..

  $ hg clone -r 3 a b
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 3 changes to 3 files
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg clone -r 4 a c
  adding changesets
  adding manifests
  adding file changes
  added 4 changesets with 3 changes to 3 files
  updating to branch default
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R a outgoing b
  comparing with b
  searching for changes
  changeset:   4:1ec3c74fc0e0
  tag:         tip
  parent:      1:79f9e10cd04e
  parent:      2:8e1bb01c1a24
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m2
  
  $ hg -R a outgoing c
  comparing with c
  searching for changes
  changeset:   3:d15a0c284984
  parent:      2:8e1bb01c1a24
  parent:      1:79f9e10cd04e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m1
  
  $ hg -R b outgoing c
  comparing with c
  searching for changes
  changeset:   3:d15a0c284984
  tag:         tip
  parent:      2:8e1bb01c1a24
  parent:      1:79f9e10cd04e
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m1
  
  $ hg -R c outgoing b
  comparing with b
  searching for changes
  changeset:   3:1ec3c74fc0e0
  tag:         tip
  parent:      1:79f9e10cd04e
  parent:      2:8e1bb01c1a24
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     m2
  

  $ hg -R b pull a
  pulling from a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg -R c pull a
  pulling from a
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)