Use new ERT skip-when macro in tests

* test/lisp/autorevert-tests.el
(auto-revert-test02-auto-revert-deleted-file):
* test/lisp/emacs-lisp/benchmark-tests.el (benchmark-tests):
* test/lisp/emacs-lisp/find-func-tests.el
(find-func-tests--library-completion):
* test/lisp/eshell/esh-proc-tests.el
(esh-proc-test/kill-pipeline):
* test/lisp/filenotify-tests.el (file-notify-test11-symlinks):
* test/lisp/ibuffer-tests.el (ibuffer-0autoload):
* test/lisp/international/ucs-normalize-tests.el
(ucs-normalize-part1):
* test/lisp/net/network-stream-tests.el (echo-server-nowait)
(connect-to-tls-ipv4-nowait, connect-to-tls-ipv6-nowait)
(open-network-stream-tls-wait, open-network-stream-tls-nowait)
(open-network-stream-tls, open-network-stream-tls-nocert)
(open-gnutls-stream-new-api-nowait)
(open-gnutls-stream-old-api-nowait):
* test/lisp/progmodes/cperl-mode-tests.el (cperl-test-bug-10483)
(cperl-test-hyperactive-electric-else):
* test/lisp/progmodes/elisp-mode-tests.el
(eval-last-sexp-print-format-sym-echo)
(eval-last-sexp-print-format-small-int-echo)
(eval-last-sexp-print-format-large-int-echo)
(eval-defun-prints-edebug-when-instrumented):
* test/lisp/progmodes/python-tests.el (python-ffap-module-path-1):
* test/lisp/shadowfile-tests.el (shadow-test00-clusters)
(shadow-test01-sites, shadow-test02-files)
(shadow-test03-expand-cluster-in-file-name)
(shadow-test04-contract-file-name, shadow-test05-file-match)
(shadow-test06-literal-groups, shadow-test07-regexp-groups)
(shadow-test08-shadow-todo, shadow-test09-shadow-copy-files):
* test/lisp/simple-tests.el
(eval-expression-print-format-sym-echo)
(eval-expression-print-format-small-int-echo)
(eval-expression-print-format-large-int-echo):
* test/lisp/term-tests.el (term-simple-lines)
(term-carriage-return, term-line-wrap, term-colors)
(term-colors-bold-is-bright, term-cursor-movement)
(term-scrolling-region, term-set-directory)
(term-line-wrapping-then-motion, term-to-margin):
* test/lisp/thread-tests.el
(thread-tests-list-threads-error-when-not-configured):
* test/lisp/vc/vc-tests.el (backend):
* test/manual/scroll-tests.el (scroll-tests-scroll-margin-0)
(scroll-tests-scroll-margin-negative)
(scroll-tests-scroll-margin-max)
(scroll-tests-scroll-margin-over-max)
(scroll-tests-scroll-margin-whole-window):
* test/misc/test-custom-libs.el (test-custom-libs):
* test/src/emacs-module-tests.el (module/async-pipe):
* test/src/fileio-tests.el (fileio-tests--odd-symlink-chars):
* test/src/filelock-tests.el (filelock-tests-lock-spoiled)
(filelock-tests-file-locked-p-spoiled)
(filelock-tests-unlock-spoiled)
(filelock-tests-kill-buffer-spoiled)
(filelock-tests-detect-external-change):
* test/src/image-tests.el
(image-tests-image-size/error-on-nongraphical-display)
(image-tests-image-mask-p/error-on-nongraphical-display)
(image-tests-image-metadata/error-on-nongraphical-display):
* test/src/process-tests.el (make-process/mix-stderr)
(process-tests/fd-setsize-no-crash/make-network-process)
(process-tests/fd-setsize-no-crash/make-serial-process):
Use ERT `skip-when` macro in tests.

test/lisp/vc/vc-tests.el

@@ -781,7 +781,7 @@ This checks also `vc-backend' and `vc-responsible-backend'."
           ;; CVS calls vc-delete-file, which insists on prompting
           ;; "Really want to delete ...?", and `vc-mtn.el' does not implement
           ;; `delete-file' at all.
-          (skip-unless (not (memq ',backend '(CVS Mtn))))
+          (skip-when (memq ',backend '(CVS Mtn)))
           (vc-test--rename-file ',backend))
 
         (ert-deftest
@@ -796,7 +796,7 @@ This checks also `vc-backend' and `vc-responsible-backend'."
                  (format "vc-test-%s01-register" backend-string))))))
           ;; `vc-mtn.el' gives me:
           ;; "Failed (status 1): mtn commit -m Testing vc-version-diff\n\n foo"
-          (skip-unless (not (memq ',backend '(Mtn))))
+          (skip-when (memq ',backend '(Mtn)))
           (vc-test--version-diff ',backend))
         ))))