* testing/lisp/test-ox-publish.el (test-org-publish/resolve-external-link):
Rewrite test to prevent race condition which could affect results.
* testing/examples/pub/b.org: Add missing keyword.
* lisp/ox-publish.el (org-publish-get-base-files): Make sure to remove
directories.
* testing/examples/pub/file.txt:
* testing/examples/pub/noextension: New files.
* testing/lisp/test-ox-publish.el (test-org-publish/base-extension):
New test.