Merged r12274 from trunk to 2.4-stable (#13348)

fix repository tree can't handle two loading at once.

Contributed by Vadim Pushtaev.

--HG--
branch : 2.4-stable
extra : convert_revision : svn%3Ae93f8b46-1217-0410-a6f0-8f06a7374b81/branches/2.4-stable%4012276