view tests/test-merge4.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.

  $ hg init
  $ echo This is file a1 > a
  $ hg add a
  $ hg commit -m "commit #0"
  $ echo This is file b1 > b
  $ hg add b
  $ hg commit -m "commit #1"
  $ hg update 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo This is file c1 > c
  $ hg add c
  $ hg commit -m "commit #2"
  created new head
  $ hg merge 1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ rm b
  $ echo This is file c22 > c

Test hg behaves when committing with a missing file added by a merge

  $ hg commit -m "commit #3"
  abort: cannot commit merge with missing files
  [255]