* test/lisp/vc/log-edit-tests.el (log-edit-fill-entry-confinement)
(log-edit-fill-entry-space-substitution)
(log-edit-fill-entry-initial-wrapping): Replace literal space character
with '\s', to avoid tripping up merge scripts.
* lisp/vc/log-edit.el (log-edit-fill-entry): Match and replace
with NBSPs the opening defun list also.
* test/lisp/vc/log-edit-tests.el
(log-edit-fill-entry-no-defun-list-wrapping): New test.
* lisp/vc/log-edit.el (log-edit--insert-filled-defuns): Don't
open a new line for long defuns at column 0.
* test/lisp/vc/log-edit-tests.el
(log-edit-fill-entry-space-substitution): Adjust expected
results to match change.
(log-edit-fill-entry-initial-wrapping): New test.
* lisp/vc/log-edit.el (log-edit-fill-entry): Replace space
characters within defun lists with NBSPs for the duration of
`fill-region''s execution, so that they are never considered
break points.
* test/lisp/vc/log-edit-tests.el
(log-edit-fill-entry-space-substitution): New test.
* lisp/vc/log-edit.el (log-edit-fill-entry): Relax regexp a bit to
recognize function entries with leading blanks.
* test/lisp/vc/log-edit-tests.el: New test.