view tests/test-trusted.py @ 11769:ca6cebd8734e stable

dirstate: ignore symlinks when fs cannot handle them (issue1888)

When the filesystem cannot handle the executable bit, we currently
ignore it completely when looking for modified files. Similarly, it is
impossible to set or clear the bit when the filesystem ignores it.

This patch makes Mercurial treat symbolic links the same way.

Symlinks are a little different since they manifest themselves as
small files containing a filename (the symlink target). On Windows,
these files show up as regular files, and on Linux and Mac they show
up as real symlinks.

Issue1888 presents a case where the symlink files are better ignored
from the Windows side. A Linux client creates symlinks in a working
copy which is shared over a network between Linux and Windows clients.

The Samba server is helpful and defererences the symlink when the
Windows client looks at it. This means that Mercurial on the Windows
side sees file content instead of a file name in the symlink, and
hence flags the link as modified. Ignoring the change would be much
more helpful, similarly to how Mercurial does not report any changes
when executable bits are ignored in a checkout on Windows.

An initial checkout of a symbolic link on a file system that cannot
handle symbolic links will still result in a regular file containing
the target file name as its content. Sharing such a checkout with a
Linux client will not turn the file into a symlink automatically, but
'hg revert' can fix that. After the revert, the Windows client will
see the correct file content (provided by the Samba server when it
follows the link on the Linux side) and otherwise ignore the change.

Running 'hg perfstatus' 10 times gives these results:

  Before:          After:
  min: 0.544703    min: 0.546549
  med: 0.547592    med: 0.548881
  avg: 0.549146    avg: 0.548549
  max: 0.564112    max: 0.551504

The median time is increased about 0.24%.

# Since it's not easy to write a test that portably deals
# with files from different users/groups, we cheat a bit by
# monkey-patching some functions in the util module

import os
from mercurial import ui, util, error

hgrc = os.environ['HGRCPATH']
f = open(hgrc)
basehgrc = f.read()
f.close()

def testui(user='foo', group='bar', tusers=(), tgroups=(),
           cuser='foo', cgroup='bar', debug=False, silent=False):
    # user, group => owners of the file
    # tusers, tgroups => trusted users/groups
    # cuser, cgroup => user/group of the current process

    # write a global hgrc with the list of trusted users/groups and
    # some setting so that we can be sure it was read
    f = open(hgrc, 'w')
    f.write(basehgrc)
    f.write('\n[paths]\n')
    f.write('global = /some/path\n\n')

    if tusers or tgroups:
        f.write('[trusted]\n')
        if tusers:
            f.write('users = %s\n' % ', '.join(tusers))
        if tgroups:
            f.write('groups = %s\n' % ', '.join(tgroups))
    f.close()

    # override the functions that give names to uids and gids
    def username(uid=None):
        if uid is None:
            return cuser
        return user
    util.username = username

    def groupname(gid=None):
        if gid is None:
            return 'bar'
        return group
    util.groupname = groupname

    def isowner(st):
        return user == cuser
    util.isowner = isowner

    # try to read everything
    #print '# File belongs to user %s, group %s' % (user, group)
    #print '# trusted users = %s; trusted groups = %s' % (tusers, tgroups)
    kind = ('different', 'same')
    who = ('', 'user', 'group', 'user and the group')
    trusted = who[(user in tusers) + 2*(group in tgroups)]
    if trusted:
        trusted = ', but we trust the ' + trusted
    print '# %s user, %s group%s' % (kind[user == cuser], kind[group == cgroup],
                                     trusted)

    u = ui.ui()
    u.setconfig('ui', 'debug', str(bool(debug)))
    u.readconfig('.hg/hgrc')
    if silent:
        return u
    print 'trusted'
    for name, path in u.configitems('paths'):
        print '   ', name, '=', path
    print 'untrusted'
    for name, path in u.configitems('paths', untrusted=True):
        print '.',
        u.config('paths', name) # warning with debug=True
        print '.',
        u.config('paths', name, untrusted=True) # no warnings
        print name, '=', path
    print

    return u

os.mkdir('repo')
os.chdir('repo')
os.mkdir('.hg')
f = open('.hg/hgrc', 'w')
f.write('[paths]\n')
f.write('local = /another/path\n\n')
f.close()

#print '# Everything is run by user foo, group bar\n'

# same user, same group
testui()
# same user, different group
testui(group='def')
# different user, same group
testui(user='abc')
# ... but we trust the group
testui(user='abc', tgroups=['bar'])
# different user, different group
testui(user='abc', group='def')
# ... but we trust the user
testui(user='abc', group='def', tusers=['abc'])
# ... but we trust the group
testui(user='abc', group='def', tgroups=['def'])
# ... but we trust the user and the group
testui(user='abc', group='def', tusers=['abc'], tgroups=['def'])
# ... but we trust all users
print '# we trust all users'
testui(user='abc', group='def', tusers=['*'])
# ... but we trust all groups
print '# we trust all groups'
testui(user='abc', group='def', tgroups=['*'])
# ... but we trust the whole universe
print '# we trust all users and groups'
testui(user='abc', group='def', tusers=['*'], tgroups=['*'])
# ... check that users and groups are in different namespaces
print "# we don't get confused by users and groups with the same name"
testui(user='abc', group='def', tusers=['def'], tgroups=['abc'])
# ... lists of user names work
print "# list of user names"
testui(user='abc', group='def', tusers=['foo', 'xyz', 'abc', 'bleh'],
       tgroups=['bar', 'baz', 'qux'])
# ... lists of group names work
print "# list of group names"
testui(user='abc', group='def', tusers=['foo', 'xyz', 'bleh'],
       tgroups=['bar', 'def', 'baz', 'qux'])

print "# Can't figure out the name of the user running this process"
testui(user='abc', group='def', cuser=None)

print "# prints debug warnings"
u = testui(user='abc', group='def', cuser='foo', debug=True)

print "# ui.readconfig sections"
filename = 'foobar'
f = open(filename, 'w')
f.write('[foobar]\n')
f.write('baz = quux\n')
f.close()
u.readconfig(filename, sections = ['foobar'])
print u.config('foobar', 'baz')

print
print "# read trusted, untrusted, new ui, trusted"
u = ui.ui()
u.setconfig('ui', 'debug', 'on')
u.readconfig(filename)
u2 = u.copy()
def username(uid=None):
    return 'foo'
util.username = username
u2.readconfig('.hg/hgrc')
print 'trusted:'
print u2.config('foobar', 'baz')
print 'untrusted:'
print u2.config('foobar', 'baz', untrusted=True)

print
print "# error handling"

def assertraises(f, exc=util.Abort):
    try:
        f()
    except exc, inst:
        print 'raised', inst.__class__.__name__
    else:
        print 'no exception?!'

print "# file doesn't exist"
os.unlink('.hg/hgrc')
assert not os.path.exists('.hg/hgrc')
testui(debug=True, silent=True)
testui(user='abc', group='def', debug=True, silent=True)

print
print "# parse error"
f = open('.hg/hgrc', 'w')
f.write('foo')
f.close()

try:
    testui(user='abc', group='def', silent=True)
except error.ParseError, inst:
    print inst

try:
    testui(debug=True, silent=True)
except error.ParseError, inst:
    print inst