Fixed a tricky bug
Fixed a tricky bug


Former-commit-id: 53d31dc4bb5bf3d23d9b822de095e821ecccf7e1
chunyang-wen/dynet,clab/dynet,danielhers/dynet,danielhers/dynet,shuheik/dynet,chunyang-wen/dynet,shuheik/dynet,chunyang-wen/dynet,clab/dynet,shuheik/dynet,clab/dynet,danielhers/dynet,xunzhang/dynet,danielhers/dynet,clab/cnn,clab/cnn,shuheik/dynet,danielhers/dynet,clab/dynet,danielhers/dynet,xunzhang/dynet,clab/cnn,danielhers/dynet,clab/dynet,xunzhang/dynet,chunyang-wen/dynet,shuheik/dynet,shuheik/dynet,clab/dynet,shuheik/dynet,clab/dynet,xunzhang/dynet