Failing test in files-tests.el on MS-Windows

[Eli Zaretskii]

Michael,

The (relatively) recently added test in files-tests.el fails on
MS-Windows:

  Test files-tests-file-name-non-special-insert-directory backtrace:
    signal(ert-test-failed (((should-error (with-temp-buffer (insert-dir
    ert-fail(((should-error (with-temp-buffer (insert-directory nospecia
    (if errorp764 nil (ert-fail (append (funcall form-description-fn-765
    (let ((errorp764 nil) (form-description-fn-765 #'(lambda nil form-de
    (let (form-description-763) (let ((errorp764 nil) (form-description-
    (let ((value-762 (gensym "ert-form-evaluation-aborted-"))) (let (for
    (progn (let ((value-762 (gensym "ert-form-evaluation-aborted-"))) (l
    (unwind-protect (progn (let ((value-762 (gensym "ert-form-evaluation
    (let* ((temporary-file-directory (file-truename temporary-file-direc
    (closure (t) nil (let* ((temporary-file-directory (file-truename tem
    ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
    ert-run-test(#s(ert-test :name files-tests-file-name-non-special-ins
    ert-run-or-rerun-test(#s(ert--stats :selector (not ...) :tests [... 
    ert-run-tests((not (tag :unstable)) #f(compiled-function (event-type
    ert-run-tests-batch((not (tag :unstable)))
    ert-run-tests-batch-and-exit((not (tag :unstable)))
    eval((ert-run-tests-batch-and-exit '(not (tag :unstable))))
    command-line-1((#("-L" 0 2 (charset cp862)) #(";." 0 2 (charset cp86
    command-line()
    normal-top-level()
  Test files-tests-file-name-non-special-insert-directory condition:
      (ert-test-failed
       ((should-error
         (with-temp-buffer
           (insert-directory nospecial-dir "")))
        :form
        (let
            ((temp-buffer ...))
          (save-current-buffer
            (set-buffer temp-buffer)
            (unwind-protect ... ...)))
        :value nil :fail-reason "did not signal an error"))
     FAILED  56/79  files-tests-file-name-non-special-insert-directory 
(2.015561 sec)
  Test files-tests-file-name-non-special-insert-directory backtrace:
    signal(ert-test-failed (((should-error (with-temp-buffer (insert-dir
    ert-fail(((should-error (with-temp-buffer (insert-directory nospecia
    (if errorp764 nil (ert-fail (append (funcall form-description-fn-765
    (let ((errorp764 nil) (form-description-fn-765 #'(lambda nil form-de
    (let (form-description-763) (let ((errorp764 nil) (form-description-
    (let ((value-762 (gensym "ert-form-evaluation-aborted-"))) (let (for
    (progn (let ((value-762 (gensym "ert-form-evaluation-aborted-"))) (l
    (unwind-protect (progn (let ((value-762 (gensym "ert-form-evaluation
    (let* ((temporary-file-directory (file-truename temporary-file-direc
    (closure (t) nil (let* ((temporary-file-directory (file-truename tem
    ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
    ert-run-test(#s(ert-test :name files-tests-file-name-non-special-ins
    ert-run-or-rerun-test(#s(ert--stats :selector (not ...) :tests [... 
    ert-run-tests((not (tag :unstable)) #f(compiled-function (event-type
    ert-run-tests-batch((not (tag :unstable)))
    ert-run-tests-batch-and-exit((not (tag :unstable)))
    eval((ert-run-tests-batch-and-exit '(not (tag :unstable))))
    command-line-1((#("-L" 0 2 (charset cp862)) #(";." 0 2 (charset cp86
    command-line()
    normal-top-level()
  Test files-tests-file-name-non-special-insert-directory condition:
      (ert-test-failed
       ((should-error
         (with-temp-buffer
           (insert-directory nospecial-dir "")))
        :form
        (let
            ((temp-buffer ...))
          (save-current-buffer
            (set-buffer temp-buffer)
            (unwind-protect ... ...)))
        :value nil :fail-reason "did not signal an error"))
     FAILED  56/79  files-tests-file-name-non-special-insert-directory 
(2.015561 sec)

If you could tell a bit regarding why the expression

  (with-temp-buffer (insert-directory nospecial-dir ""))

is supposed to signal an error here, I could look into the possible
reason(s).

Thanks.