* mm-partial.el (mm-partial-find-parts): Use with-current-buffer.

* mm-partial.el (mm-partial-find-parts): Use with-current-buffer.

* nnfolder.el (nnfolder-generate-active-file): Use dolist.

* nnmail.el (nnmail-split-history): do.

* nnml.el (nnml-generate-nov-databases-1, nnml-request-rename-group)
(nnml-request-delete-group): do.

* nnslashdot.el (nnslashdot-read-groups): do.

* nnsoup.el (nnsoup-delete-unreferenced-message-files): do.
(nnsoup-unpack-packets, nnsoup-make-active): Simplify.

* nnspool.el (nnspool-find-id): Use with-temp-buffer.
(nnspool-sift-nov-with-sed): Use last
(nnspool-retrieve-headers-with-nov): Use mapc.
(nnspool-request-newgroups): Use dolist.
(nnspool-request-group): Use last.

* nntp.el (nntp-read-server-type): Use dolist.

* nnvirtual.el (nnvirtual-create-mapping)
(nnvirtual-update-read-and-marked): Use dolist.
(nnvirtual-convert-headers): Simplify.