tests/test-merge-symlinks.t

wireprotoserver: rename abstractserverproto and improve docstring

The docstring isn't completely accurate for the current state
of the world. But it does describe the direction future patches
will be taking things.

Differential Revision: https://phab.mercurial-scm.org/D2065

  $ cat > echo.py <<EOF
  > #!$PYTHON
  > from __future__ import absolute_import, print_function
  > import os
  > import sys
  > try:
  >     import msvcrt
  >     msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
  >     msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
  > except ImportError:
  >     pass
  > 
  > for k in ('HG_FILE', 'HG_MY_ISLINK', 'HG_OTHER_ISLINK', 'HG_BASE_ISLINK'):
  >     print(k, os.environ[k])
  > EOF

Create 2 heads containing the same file, once as
a file, once as a link. Bundle was generated with:

# hg init t
# cd t
# echo a > a
# hg ci -qAm t0 -d '0 0'
# echo l > l
# hg ci -qAm t1 -d '1 0'
# hg up -C 0
# ln -s a l
# hg ci -qAm t2 -d '2 0'
# echo l2 > l2
# hg ci -qAm t3 -d '3 0'

  $ hg init t
  $ cd t
  $ hg -q pull "$TESTDIR/bundles/test-merge-symlinks.hg"
  $ hg up -C 3
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

Merge them and display *_ISLINK vars
merge heads

  $ hg merge --tool="$PYTHON ../echo.py"
  merging l
  HG_FILE l
  HG_MY_ISLINK 1
  HG_OTHER_ISLINK 0
  HG_BASE_ISLINK 0
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Test working directory symlink bit calculation wrt copies,
especially on non-supporting systems.
merge working directory

  $ hg up -C 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg copy l l2
  $ HGMERGE="$PYTHON ../echo.py" hg up 3
  merging l2
  HG_FILE l2
  HG_MY_ISLINK 1
  HG_OTHER_ISLINK 0
  HG_BASE_ISLINK 0
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved

  $ cd ..