transport-helper: implement marks location as capability

Now that the gitdir location is exported as an environment variable
this can be implemented elegantly without requiring any explicit
flushes nor an ad-hoc exchange of values.

Signed-off-by: Sverre Rabbelier <srabbelier@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

git-remote-testgit.py

@@ -72,6 +72,17 @@ def do_capabilities(repo, args):
     print "export"
     print "refspec refs/heads/*:%s*" % repo.prefix
 
+    dirname = repo.get_base_path(repo.gitdir)
+
+    if not os.path.exists(dirname):
+        os.makedirs(dirname)
+
+    path = os.path.join(dirname, 'testgit.marks')
+
+    print "*export-marks %s" % path
+    if os.path.exists(path):
+        print "*import-marks %s" % path
+
     print # end capabilities
 
 
@@ -147,19 +158,6 @@ def do_export(repo, args):
     if not repo.gitdir:
         die("Need gitdir to export")
 
-    dirname = repo.get_base_path(repo.gitdir)
-
-    if not os.path.exists(dirname):
-        os.makedirs(dirname)
-
-    path = os.path.join(dirname, 'testgit.marks')
-    print path
-    if os.path.exists(path):
-        print path
-    else:
-        print ""
-    sys.stdout.flush()
-
     update_local_repo(repo)
     changed = repo.importer.do_import(repo.gitdir)