new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/__init__.py
@@ -0,0 +1,311 @@
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+"""Robustly perform a checkout.
+
+This extension provides the ``hg robustcheckout`` command for
+ensuring a working directory is updated to the specified revision
+from a source repo using best practices to ensure optimal clone
+times and storage efficiency.
+"""
+
+from __future__ import absolute_import
+
+import contextlib
+import errno
+import functools
+import os
+import re
+
+from mercurial.i18n import _
+from mercurial import (
+    commands,
+    error,
+    exchange,
+    extensions,
+    cmdutil,
+    hg,
+    scmutil,
+    util,
+)
+
+testedwith = '3.5 3.6 3.7 3.8'
+minimumhgversion = '3.7'
+
+cmdtable = {}
+command = cmdutil.command(cmdtable)
+
+
+if os.name == 'nt':
+    import ctypes
+
+    # Get a reference to the DeleteFileW function
+    # DeleteFileW accepts filenames encoded as a null terminated sequence of
+    # wide chars (UTF-16). Python's ctypes.c_wchar_p correctly encodes unicode
+    # strings to null terminated UTF-16 strings.
+    # However, we receive (byte) strings from mercurial. When these are passed
+    # to DeleteFileW via the c_wchar_p type, they are implicitly decoded via
+    # the 'mbcs' encoding on windows.
+    kernel32 = ctypes.windll.kernel32
+    DeleteFile = kernel32.DeleteFileW
+    DeleteFile.argtypes = [ctypes.c_wchar_p]
+    DeleteFile.restype = ctypes.c_bool
+
+    def unlinklong(fn):
+        normalized_path = '\\\\?\\' + os.path.normpath(fn)
+        if not DeleteFile(normalized_path):
+            raise OSError(errno.EPERM, "couldn't remove long path", fn)
+
+# Not needed on other platforms, but is handy for testing
+else:
+    def unlinklong(fn):
+        os.unlink(fn)
+
+
+def unlinkwrapper(unlinkorig, fn, ui):
+    '''Calls unlink_long if original unlink function fails.'''
+    try:
+        ui.debug('calling unlink_orig %s\n' % fn)
+        return unlinkorig(fn)
+    except WindowsError as e:
+        # Windows error 3 corresponds to ERROR_PATH_NOT_FOUND
+        # only handle this case; re-raise the exception for other kinds of
+        # failures.
+        if e.winerror != 3:
+            raise
+        ui.debug('caught WindowsError ERROR_PATH_NOT_FOUND; '
+                 'calling unlink_long %s\n' % fn)
+        return unlinklong(fn)
+
+
+@contextlib.contextmanager
+def wrapunlink(ui):
+    '''Context manager that temporarily monkeypatches unlink functions.'''
+    purgemod = extensions.find('purge')
+    to_wrap = [(purgemod.util, 'unlink')]
+
+    # Pass along the ui object to the unlink_wrapper so we can get logging out
+    # of it.
+    wrapped = functools.partial(unlinkwrapper, ui=ui)
+
+    # Wrap the original function(s) with our unlink wrapper.
+    originals = {}
+    for mod, func in to_wrap:
+        ui.debug('wrapping %s %s\n' % (mod, func))
+        originals[mod, func] = extensions.wrapfunction(mod, func, wrapped)
+
+    try:
+        yield
+    finally:
+        # Restore the originals.
+        for mod, func in to_wrap:
+            ui.debug('restoring %s %s\n' % (mod, func))
+            setattr(mod, func, originals[mod, func])
+
+
+def purgewrapper(orig, ui, *args, **kwargs):
+    '''Runs original purge() command with unlink monkeypatched.'''
+    with wrapunlink(ui):
+        return orig(ui, *args, **kwargs)
+
+
+@command('robustcheckout', [
+    ('', 'upstream', '', 'URL of upstream repo to clone from'),
+    ('r', 'revision', '', 'Revision to check out'),
+    ('b', 'branch', '', 'Branch to check out'),
+    ('', 'purge', False, 'Whether to purge the working directory'),
+    ('', 'sharebase', '', 'Directory where shared repos should be placed'),
+    ],
+    '[OPTION]... URL DEST',
+    norepo=True)
+def robustcheckout(ui, url, dest, upstream=None, revision=None, branch=None,
+                   purge=False, sharebase=None):
+    """Ensure a working copy has the specified revision checked out."""
+    if not revision and not branch:
+        raise error.Abort('must specify one of --revision or --branch')
+
+    if revision and branch:
+        raise error.Abort('cannot specify both --revision and --branch')
+
+    sharebase = sharebase or ui.config('share', 'pool')
+    if not sharebase:
+        raise error.Abort('share base directory not defined; refusing to operate',
+                          hint='define share.pool config option or pass --sharebase')
+
+    # worker.backgroundclose only makes things faster if running anti-virus,
+    # which our automation doesn't. Disable it.
+    ui.setconfig('worker', 'backgroundclose', False)
+
+    sharebase = os.path.realpath(sharebase)
+
+    return _docheckout(ui, url, dest, upstream, revision, branch, purge,
+                       sharebase)
+
+def _docheckout(ui, url, dest, upstream, revision, branch, purge, sharebase):
+    def callself():
+        return _docheckout(ui, url, dest, upstream, revision, branch, purge,
+                           sharebase)
+
+    ui.write('ensuring %s@%s is available at %s\n' % (url, revision or branch,
+                                                      dest))
+
+    destvfs = scmutil.vfs(dest, audit=False, realpath=True)
+
+    if destvfs.exists() and not destvfs.exists('.hg'):
+        raise error.Abort('destination exists but no .hg directory')
+
+    # Require checkouts to be tied to shared storage because efficiency.
+    if destvfs.exists('.hg') and not destvfs.exists('.hg/sharedpath'):
+        ui.warn('(destination is not shared; deleting)\n')
+        destvfs.rmtree(forcibly=True)
+
+    # Verify the shared path exists and is using modern pooled storage.
+    if destvfs.exists('.hg/sharedpath'):
+        storepath = destvfs.read('.hg/sharedpath').strip()
+
+        ui.write('(existing repository shared store: %s)\n' % storepath)
+
+        if not os.path.exists(storepath):
+            ui.warn('(shared store does not exist; deleting)\n')
+            destvfs.rmtree(forcibly=True)
+        elif not re.search('[a-f0-9]{40}/\.hg$', storepath.replace('\\', '/')):
+            ui.warn('(shared store does not belong to pooled storage; '
+                    'deleting to improve efficiency)\n')
+            destvfs.rmtree(forcibly=True)
+
+        # FUTURE when we require generaldelta, this is where we can check
+        # for that.
+
+    def deletesharedstore():
+        storepath = destvfs.read('.hg/sharedpath').strip()
+        if storepath.endswith('.hg'):
+            storepath = os.path.dirname(storepath)
+
+        storevfs = scmutil.vfs(storepath, audit=False)
+        storevfs.rmtree(forcibly=True)
+
+    def handlerepoerror(e):
+        if e.message == _('abandoned transaction found'):
+            ui.warn('(abandoned transaction found; trying to recover)\n')
+            repo = hg.repository(ui, dest)
+            if not repo.recover():
+                ui.warn('(could not recover repo state; '
+                        'deleting shared store)\n')
+                deletesharedstore()
+
+            ui.warn('(attempting checkout from beginning)\n')
+            return callself()
+
+        raise
+
+    # At this point we either have an existing working directory using
+    # shared, pooled storage or we have nothing.
+    created = False
+
+    if not destvfs.exists():
+        # Ensure parent directories of destination exist.
+        # Mercurial 3.8 removed ensuredirs and made makedirs race safe.
+        if util.safehasattr(util, 'ensuredirs'):
+            makedirs = util.ensuredirs
+        else:
+            makedirs = util.makedirs
+
+        makedirs(os.path.dirname(destvfs.base), notindexed=True)
+        makedirs(sharebase, notindexed=True)
+
+        if upstream:
+            ui.write('(cloning from upstream repo %s)\n' % upstream)
+        cloneurl = upstream or url
+
+        try:
+            res = hg.clone(ui, {}, cloneurl, dest=dest, update=False,
+                           shareopts={'pool': sharebase, 'mode': 'identity'})
+        except error.RepoError as e:
+            return handlerepoerror(e)
+        except error.RevlogError as e:
+            ui.warn('(repo corruption: %s; deleting shared store)\n' % e.message)
+            deletesharedstore()
+            return callself()
+
+        # TODO retry here.
+        if res is None:
+            raise error.Abort('clone failed')
+
+        # Verify it is using shared pool storage.
+        if not destvfs.exists('.hg/sharedpath'):
+            raise error.Abort('clone did not create a shared repo')
+
+        created = True
+
+    # The destination .hg directory should exist. Now make sure we have the
+    # wanted revision.
+
+    repo = hg.repository(ui, dest)
+    havewantedrev = False
+    if revision:
+        havewantedrev = revision in repo
+    else:
+        assert branch
+        # Branch names are not constant over time, so always pull to
+        # ensure we have the latest revision.
+
+    if not havewantedrev:
+        ui.write('(pulling to obtain %s)\n' % (revision or branch,))
+
+        try:
+            remote = hg.peer(repo, {}, url)
+            pullrevs = [remote.lookup(revision or branch)]
+            pullop = exchange.pull(repo, remote, heads=pullrevs)
+            if not pullop.rheads:
+                raise error.Abort('unable to pull requested revision')
+        except error.Abort as e:
+            if e.message == _('repository is unrelated'):
+                ui.warn('(repository is unrelated; deleting)\n')
+                destvfs.rmtree(forcibly=True)
+                return callself()
+
+            raise
+        except error.RepoError as e:
+            return handlerepoerror(e)
+        except error.RevlogError as e:
+            ui.warn('(repo corruption: %s; deleting shared store)\n' % e.message)
+            deletesharedstore()
+            return callself()
+        finally:
+            remote.close()
+
+    # Now we should have the wanted revision in the store. Perform
+    # working directory manipulation.
+
+    # Purge if requested. We purge before update because this way we're
+    # guaranteed to not have conflicts on `hg update`.
+    if purge and not created:
+        ui.write('(purging working directory)\n')
+        purgeext = extensions.find('purge')
+
+        if purgeext.purge(ui, repo, all=True, abort_on_err=True,
+                          # The function expects all arguments to be
+                          # defined.
+                          **{'print': None, 'print0': None, 'dirs': None,
+                             'files': None}):
+            raise error.Abort('error purging')
+
+    # Update the working directory.
+    if commands.update(ui, repo, rev=revision or branch, clean=True):
+        raise error.Abort('error updating')
+
+    ctx = repo[revision or branch]
+    ui.write('updated to %s\n' % ctx.hex())
+    return None
+
+
+def extsetup(ui):
+    # Ensure required extensions are loaded.
+    for ext in ('purge', 'share'):
+        try:
+            extensions.find(ext)
+        except KeyError:
+            extensions.load(ui, ext, None)
+
+    purgemod = extensions.find('purge')
+    extensions.wrapcommand(purgemod.cmdtable, 'purge', purgewrapper)

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/helpers.sh
@@ -0,0 +1,41 @@
+cat >> $HGRCPATH << EOF
+[share]
+pool = $TESTTMP/share
+
+[extensions]
+robustcheckout = $TESTDIR/hgext/robustcheckout
+EOF
+
+mkdir server
+hg init server/repo0
+hg init server/repo1
+
+cd server/repo0
+
+touch foo
+hg -q commit -A -m initial0
+echo 1 > foo
+hg commit -m 1
+hg -q up -r 0
+hg -q branch branch1
+echo branch1 > foo
+hg commit -m branch1
+
+cd ../repo1
+touch foo
+hg -q commit -A -m initial1
+echo 1 > foo
+hg commit -m 1
+cd ..
+
+hg -q clone -r 0 --pull -U repo0 repo0-upstream
+
+cat >> hgweb.conf << EOF
+[paths]
+/ = $TESTTMP/server/*
+EOF
+
+hg serve -d -p $HGPORT --pid-file hg.pid --web-conf hgweb.conf
+cat hg.pid >> $DAEMON_PIDS
+
+cd $TESTTMP
\ No newline at end of file

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-abandonded-transaction.t
@@ -0,0 +1,65 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ hg -R dest --config extensions.strip= strip -r aada1b3e573f --no-backup
+
+Simulate an abandonded transaction
+
+  $ touch $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg/store/journal
+
+Pulling when there is an abandoned transaction should automatically recover
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision aada1b3e573f
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain aada1b3e573f)
+  searching for changes
+  (abandoned transaction found; trying to recover)
+  rolling back interrupted transaction
+  (attempting checkout from beginning)
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain aada1b3e573f)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44
+
+Now simulate an abandoned transaction on an initial checkout
+
+  $ hg -R dest --config extensions.strip= strip -r aada1b3e573f --no-backup
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ touch $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg/store/journal
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest2 --revision aada1b3e573f
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest2
+  (sharing from existing pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  searching for changes
+  (abandoned transaction found; trying to recover)
+  rolling back interrupted transaction
+  (attempting checkout from beginning)
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest2
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain aada1b3e573f)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-corrupt-repo.t
@@ -0,0 +1,75 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+  $ hg -R dest --config extensions.strip= strip -r aada1b3e573f --no-backup
+
+Corrupt the manifest
+
+  $ cat >> $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg/store/00manifest.i << EOF
+  > baddata
+  > EOF
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision aada1b3e573f
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain aada1b3e573f)
+  searching for changes
+  adding changesets
+  adding manifests
+  transaction abort!
+  rollback completed
+  (repo corruption: index 00manifest.i is corrupted; deleting shared store)
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (shared store does not exist; deleting)
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44
+
+Now check corruption is handled during clone
+
+  $ hg -R dest --config extensions.strip= strip -r aada1b3e573f --no-backup
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cat >> $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg/store/00manifest.i << EOF
+  > baddata
+  > EOF
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest1 --revision aada1b3e573f
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest1
+  (sharing from existing pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  searching for changes
+  adding changesets
+  adding manifests
+  transaction abort!
+  rollback completed
+  (repo corruption: index 00manifest.i is corrupted; deleting shared store)
+  ensuring http://localhost:$HGPORT/repo0@aada1b3e573f is available at dest1
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (shared store does not exist; deleting)
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-dest-no-hg.t
@@ -0,0 +1,16 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+Cloning to an existing directory that isn't a hg checkout will abort
+
+  $ mkdir dest
+  $ touch dest/file0
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision tip
+  ensuring http://localhost:$HGPORT/repo0@tip is available at dest
+  abort: destination exists but no .hg directory
+  [255]
+
+file0 should still be present
+
+  $ ls dest
+  file0

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-dest-shared-state.t
@@ -0,0 +1,70 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+Checking out to an existing repo that isn't shared will blow it away
+
+  $ hg init dest0
+  $ touch dest0/file0
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest0 --revision tip
+  ensuring http://localhost:$HGPORT/repo0@tip is available at dest0
+  (destination is not shared; deleting)
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44
+
+  $ ls dest0
+  foo
+
+If shared path points nowhere, repo is "corrupt"; should be blown away
+
+  $ hg share -U dest0 missingsharepath
+  $ cat > missingsharepath/.hg/sharedpath << EOF
+  > does_not_exist
+  > EOF
+  $ touch missingsharepath/file0
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 missingsharepath --revision tip
+  ensuring http://localhost:$HGPORT/repo0@tip is available at missingsharepath
+  (existing repository shared store: does_not_exist)
+  (shared store does not exist; deleting)
+  (sharing from existing pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44
+
+  $ ls missingsharepath
+  foo
+
+  $ cat missingsharepath/.hg/sharedpath
+  $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg (no-eol)
+
+If shared path does not point to pooled storage, it should get nuked as
+we require pooled storage
+
+  $ hg share -U dest0 nopoolshare
+  $ hg init fakeshare
+  $ cat > nopoolshare/.hg/sharedpath << EOF
+  > $TESTTMP/fakeshare/.hg
+  > EOF
+
+  $ touch nopoolshare/file0
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 nopoolshare --revision tip
+  ensuring http://localhost:$HGPORT/repo0@tip is available at nopoolshare
+  (existing repository shared store: $TESTTMP/fakeshare/.hg)
+  (shared store does not belong to pooled storage; deleting to improve efficiency)
+  (sharing from existing pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44
+
+  $ ls nopoolshare
+  foo

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-missing-parent-dirs.t
@@ -0,0 +1,31 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+Missing parent of destination directory will be created automatically
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 parent0/parent1/dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at parent0/parent1/dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+Missing parent of share pool directory will be created automatically
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b --sharebase shareparent/sharebase
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-purge.t
@@ -0,0 +1,69 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+Not specifying --purge won't purge checkout
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ touch dest/file0
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ ls dest
+  file0
+  foo
+
+Specifying purge will delete files
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b --purge
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (purging working directory)
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ ls dest
+  foo
+
+Ignored files are also purged when requested
+
+  $ cd dest
+  $ cat > .hgignore << EOF
+  > .pyc$
+  > EOF
+  $ hg -q commit -A -m hgignore
+
+  $ touch foo.pyc
+  $ cd ..
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ ls dest
+  foo
+  foo.pyc
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b --purge
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (purging working directory)
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+  $ ls dest
+  foo

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-revision-branch.t
@@ -0,0 +1,58 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+Must specify revision or branch argument
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest
+  abort: must specify one of --revision or --branch
+  [255]
+
+Only 1 of revision and branch can be specified
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --branch default --revision 5d6cdc75a09b
+  abort: cannot specify both --revision and --branch
+  [255]
+
+Specifying branch argument will checkout branch
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --branch default
+  ensuring http://localhost:$HGPORT/repo0@default is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  (pulling to obtain default)
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+Specifying branch argument will always attempt to pull because branch revisions can change
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --branch default
+  ensuring http://localhost:$HGPORT/repo0@default is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain default)
+  no changes found
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+Updating to another branch works
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --branch branch1
+  ensuring http://localhost:$HGPORT/repo0@branch1 is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain branch1)
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to aada1b3e573f7272bb2ef93b34acbf0f77c69d44
+
+Specifying revision will switch away from branch
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-unrelated.t
@@ -0,0 +1,53 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+Attempting to pull/checkout an unrelated repo will blow away the destination
+
+  $ touch dest/file0
+  $ hg robustcheckout http://localhost:$HGPORT/repo1 dest --revision 7d5b54cb09e1
+  ensuring http://localhost:$HGPORT/repo1@7d5b54cb09e1 is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (pulling to obtain 7d5b54cb09e1)
+  searching for changes
+  (repository is unrelated; deleting)
+  ensuring http://localhost:$HGPORT/repo1@7d5b54cb09e1 is available at dest
+  (sharing from new pooled repository 65cd4e3b46a3f22a08ec4162871e67f57c322f6a)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 2 changesets with 2 changes to 1 files
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 7d5b54cb09e1172a3684402520112cab3f3a1b70
+
+  $ ls dest
+  foo
+
+And again for safe measure
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/65cd4e3b46a3f22a08ec4162871e67f57c322f6a/.hg)
+  (pulling to obtain 5d6cdc75a09b)
+  searching for changes
+  (repository is unrelated; deleting)
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from existing pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-update.t
@@ -0,0 +1,73 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 3 changesets with 3 changes to 1 files (+1 heads)
+  searching for changes
+  no changes found
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+Modifications to a tracked file should get lost during update
+
+  $ cat dest/foo
+  1
+
+  $ cat > dest/foo << EOF
+  > modified
+  > EOF
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ cat dest/foo
+  1
+
+Modifications should also get lost when updating to new revision
+
+  $ cat > dest/foo << EOF
+  > modified
+  > EOF
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision b8b78f0253d8
+  ensuring http://localhost:$HGPORT/repo0@b8b78f0253d8 is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to b8b78f0253d822e33ba652fd3d80a5c0837cfdf3
+
+  $ cat dest/foo
+
+Added and copied files will be lost during update
+
+  $ cd dest
+  $ touch bar
+  $ hg add bar
+  $ hg mv foo baz
+  $ cd ..
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ hg -R dest status
+  ? bar
+  ? baz
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --revision 5d6cdc75a09b --purge
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (existing repository shared store: $TESTTMP/share/b8b78f0253d822e33ba652fd3d80a5c0837cfdf3/.hg)
+  (purging working directory)
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce
+
+  $ hg -R dest status

new file mode 100644
--- /dev/null
+++ b/hgext/robustcheckout/tests/test-upstream.t
@@ -0,0 +1,23 @@
+  $ . $TESTDIR/hgext/robustcheckout/tests/helpers.sh
+
+Specifying an upstream repo will clone from it and pull from normal repo
+
+  $ hg robustcheckout http://localhost:$HGPORT/repo0 dest --upstream http://localhost:$HGPORT/repo0-upstream --revision 5d6cdc75a09b
+  ensuring http://localhost:$HGPORT/repo0@5d6cdc75a09b is available at dest
+  (cloning from upstream repo http://localhost:$HGPORT/repo0-upstream)
+  (sharing from new pooled repository b8b78f0253d822e33ba652fd3d80a5c0837cfdf3)
+  requesting all changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  searching for changes
+  no changes found
+  (pulling to obtain 5d6cdc75a09b)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  updated to 5d6cdc75a09bcccf76f9339a28e1d89360c59dce