tests/test-check-code.t

hardlink: check directory's st_dev when copying files

Previously, when copying a file, copyfiles will compare src's st_dev with
dirname(dst)'s st_dev, to decide whether to enable hardlink or not.

That could have issues on Linux's overlayfs, where stating directories could
result in different st_dev from st_dev of stating files, even if both the
directories and the files exist in the overlay's upperdir.

This patch fixes it by checking dirname(src) instead. It's more consistent
because we are checking directories for both src and dest.

That fixes test-hardlinks.t running on common Docker setups.

#require test-repo

  $ . "$TESTDIR/helpers-testrepo.sh"
  $ check_code="$TESTDIR"/../contrib/check-code.py
  $ cd "$TESTDIR"/..

New errors are not allowed. Warnings are strongly discouraged.
(The writing "no-che?k-code" is for not skipping this file when checking.)

  $ hg locate -X contrib/python-zstandard -X hgext/fsmonitor/pywatchman |
  > sed 's-\\-/-g' | xargs "$check_code" --warnings --per-file=0 || false
  Skipping i18n/polib.py it has no-che?k-code (glob)
  mercurial/demandimport.py:312:
   >     if os.environ.get('HGDEMANDIMPORT') != 'disable':
   use encoding.environ instead (py3)
  mercurial/encoding.py:54:
   >     environ = os.environ
   use encoding.environ instead (py3)
  mercurial/encoding.py:56:
   >     environ = os.environb
   use encoding.environ instead (py3)
  mercurial/encoding.py:61:
   >                    for k, v in os.environ.items())
   use encoding.environ instead (py3)
  mercurial/encoding.py:221:
   >                    for k, v in os.environ.items())
   use encoding.environ instead (py3)
  Skipping mercurial/httpclient/__init__.py it has no-che?k-code (glob)
  Skipping mercurial/httpclient/_readers.py it has no-che?k-code (glob)
  mercurial/policy.py:46:
   >     if 'HGMODULEPOLICY' in os.environ:
   use encoding.environ instead (py3)
  mercurial/policy.py:47:
   >         policy = os.environ['HGMODULEPOLICY'].encode('utf-8')
   use encoding.environ instead (py3)
  mercurial/policy.py:49:
   >     policy = os.environ.get('HGMODULEPOLICY', policy)
   use encoding.environ instead (py3)
  Skipping mercurial/statprof.py it has no-che?k-code (glob)
  [1]

@commands in debugcommands.py should be in alphabetical order.

  >>> import re
  >>> commands = []
  >>> with open('mercurial/debugcommands.py', 'rb') as fh:
  ...     for line in fh:
  ...         m = re.match("^@command\('([a-z]+)", line)
  ...         if m:
  ...             commands.append(m.group(1))
  >>> scommands = list(sorted(commands))
  >>> for i, command in enumerate(scommands):
  ...     if command != commands[i]:
  ...         print('commands in debugcommands.py not sorted; first differing '
  ...               'command is %s; expected %s' % (commands[i], command))
  ...         break