* lisp/whitespace.el (whitespace-display-char-on): Correct the way
the original buffer-display-table is saved and restored when
global-whitespace-mode is active. (Bug#26892)
* test/lisp/whitespace-tests.el
(whitespace-tests-whitespace-mode-on): New function.
(whitespace-tests-display-tables): New test.
Copyright-paperwork-exempt: yes
* lisp/whitespace.el (whitespace-empty-at-eob-regexp): Match any number
of empty lines at end of buffer.
* test/lisp/whitespace-tests.el (whitespace-cleanup-eob): New test.
(whitespace-tests--cleanup-string): New helper function for tests.