mercurial: move imports from top-level to prevent from loading mercurial code on hook execution for svn/git

vcsserver/hooks.py

@@ -33,7 +33,6 b' import mercurial.node'
 import simplejson as json
 
 from vcsserver import exceptions, subprocessio, settings
-from vcsserver.hgcompat import get_ctx
 
 log = logging.getLogger(__name__)
 
@@ -184,6 +183,7 b' def _extras_from_ui(ui):'
 
 
 def _rev_range_hash(repo, node, check_heads=False):
+    from vcsserver.hgcompat import get_ctx
 
     commits = []
     revs = []
@@ -203,6 +203,7 b' def _rev_range_hash(repo, node, check_he'
 
 
 def _check_heads(repo, start, end, commits):
+    from vcsserver.hgcompat import get_ctx
     changelog = repo.changelog
     parents = set()
 
@@ -393,6 +394,7 b' def post_push_ssh(ui, repo, node, **kwar'
 
 
 def key_push(ui, repo, **kwargs):
+    from vcsserver.hgcompat import get_ctx
     if kwargs['new'] != '0' and kwargs['namespace'] == 'bookmarks':
         # store new bookmarks in our UI object propagated later to post_push
         ui._rc_pushkey_branches = get_ctx(repo, kwargs['key']).bookmarks()