* helm-grep.el (helm-grep-use-ack-p): Fix ls-git,check if recursive command is set.
(helm-grep--prepare-cmd-line): no need to bind default-directory here.
(helm-grep-init): bind default-directory here.
(helm-do-grep-1): Remove unused var.
* helm-grep.el: Remove definition of `helm-grep-last-default-directory'.