tests/test-inherit-mode.t

sshpeer: allow for additional environment passing to ssh exe

We already have the ability to customize the ssh command line arguments, let's
add the ability to customize its environment as well.

Example use-case is ssh.exe from Git on Windows. If `HOME` enviroment variable
is present and has some non-empty value, ssh.exe will try to access that
location for some stuff (for example, it seems for resolving `~` in
`.ssh/config`). Git for Windows seems to sometimess set this variable to the
value of `/home/username` which probably works under Git Bash, but does not
work in a native `cmd.exe` or `powershell`. Whatever the root cause, setting
`HOME` to be an empty string heals things. Therefore, some distributors
might want to set `sshenv.HOME=` in the configuration (seems less intrusive
that forcing everyone to tweak their env).

Test Plan:
- rt

Differential Revision: https://phab.mercurial-scm.org/D1683

#require unix-permissions

test that new files created in .hg inherit the permissions from .hg/store

  $ mkdir dir

just in case somebody has a strange $TMPDIR

  $ chmod g-s dir
  $ cd dir

  $ cat >printmodes.py <<EOF
  > from __future__ import absolute_import, print_function
  > import os
  > import sys
  > 
  > allnames = []
  > isdir = {}
  > for root, dirs, files in os.walk(sys.argv[1]):
  >     for d in dirs:
  >         name = os.path.join(root, d)
  >         isdir[name] = 1
  >         allnames.append(name)
  >     for f in files:
  >         name = os.path.join(root, f)
  >         allnames.append(name)
  > allnames.sort()
  > for name in allnames:
  >     suffix = name in isdir and '/' or ''
  >     print('%05o %s%s' % (os.lstat(name).st_mode & 0o7777, name, suffix))
  > EOF

  $ cat >mode.py <<EOF
  > from __future__ import absolute_import, print_function
  > import os
  > import sys
  > print('%05o' % os.lstat(sys.argv[1]).st_mode)
  > EOF

  $ umask 077

  $ hg init repo
  $ cd repo

  $ chmod 0770 .hg/store

before commit
store can be written by the group, other files cannot
store is setgid

  $ $PYTHON ../printmodes.py .
  00700 ./.hg/
  00600 ./.hg/00changelog.i
  00600 ./.hg/requires
  00770 ./.hg/store/

  $ mkdir dir
  $ touch foo dir/bar
  $ hg ci -qAm 'add files'

after commit
working dir files can only be written by the owner
files created in .hg can be written by the group
(in particular, store/**, dirstate, branch cache file, undo files)
new directories are setgid

  $ $PYTHON ../printmodes.py .
  00700 ./.hg/
  00600 ./.hg/00changelog.i
  00770 ./.hg/cache/
  00660 ./.hg/cache/branch2-served
  00660 ./.hg/cache/rbc-names-v1
  00660 ./.hg/cache/rbc-revs-v1
  00660 ./.hg/dirstate
  00660 ./.hg/fsmonitor.state (fsmonitor !)
  00660 ./.hg/last-message.txt
  00600 ./.hg/requires
  00770 ./.hg/store/
  00660 ./.hg/store/00changelog.i
  00660 ./.hg/store/00manifest.i
  00770 ./.hg/store/data/
  00770 ./.hg/store/data/dir/
  00660 ./.hg/store/data/dir/bar.i
  00660 ./.hg/store/data/foo.i
  00660 ./.hg/store/fncache
  00660 ./.hg/store/phaseroots
  00660 ./.hg/store/undo
  00660 ./.hg/store/undo.backupfiles
  00660 ./.hg/store/undo.phaseroots
  00660 ./.hg/undo.backup.dirstate
  00660 ./.hg/undo.bookmarks
  00660 ./.hg/undo.branch
  00660 ./.hg/undo.desc
  00660 ./.hg/undo.dirstate
  00700 ./dir/
  00600 ./dir/bar
  00600 ./foo

  $ umask 007
  $ hg init ../push

before push
group can write everything

  $ $PYTHON ../printmodes.py ../push
  00770 ../push/.hg/
  00660 ../push/.hg/00changelog.i
  00660 ../push/.hg/requires
  00770 ../push/.hg/store/

  $ umask 077
  $ hg -q push ../push

after push
group can still write everything

  $ $PYTHON ../printmodes.py ../push
  00770 ../push/.hg/
  00660 ../push/.hg/00changelog.i
  00770 ../push/.hg/cache/
  00660 ../push/.hg/cache/branch2-base
  00660 ../push/.hg/dirstate
  00660 ../push/.hg/requires
  00770 ../push/.hg/store/
  00660 ../push/.hg/store/00changelog.i
  00660 ../push/.hg/store/00manifest.i
  00770 ../push/.hg/store/data/
  00770 ../push/.hg/store/data/dir/
  00660 ../push/.hg/store/data/dir/bar.i
  00660 ../push/.hg/store/data/foo.i
  00660 ../push/.hg/store/fncache
  00660 ../push/.hg/store/undo
  00660 ../push/.hg/store/undo.backupfiles
  00660 ../push/.hg/store/undo.phaseroots
  00660 ../push/.hg/undo.bookmarks
  00660 ../push/.hg/undo.branch
  00660 ../push/.hg/undo.desc
  00660 ../push/.hg/undo.dirstate


Test that we don't lose the setgid bit when we call chmod.
Not all systems support setgid directories (e.g. HFS+), so
just check that directories have the same mode.

  $ cd ..
  $ hg init setgid
  $ cd setgid
  $ chmod g+rwx .hg/store
  $ chmod g+s .hg/store 2> /dev/null || true
  $ mkdir dir
  $ touch dir/file
  $ hg ci -qAm 'add dir/file'
  $ storemode=`$PYTHON ../mode.py .hg/store`
  $ dirmode=`$PYTHON ../mode.py .hg/store/data/dir`
  $ if [ "$storemode" != "$dirmode" ]; then
  >  echo "$storemode != $dirmode"
  > fi
  $ cd ..

  $ cd .. # g-s dir