* wl-folder.el (wl-folder-create-folder-entity): Use

* wl-folder.el (wl-folder-create-folder-entity): Use
with-current-buffer.
(wl-local-folder-init): Call set-buffer to make sure we are in
the Folder buffer. Don't touch buffer-local variables here.
(wl-folder-mode): Initialize buffer-local variables here.

* wl-folder.el (wl-folder-get-path): Use let instead of let*.
(wl-folder-entity-assign-id): Ditto.
(wl-folder-create-entity-hashtb): Ditto.
(wl-local-folder-init): Ditto.
(wl-folder-create-group-alist): Initialize `cur-alist' with let.