Improve log-view-copy-revision-as-kill

* lisp/vc/log-view.el (log-view-copy-revision-as-kill): Signal
user-error if there is no revision at point.
* doc/emacs/maintaining.texi (VC Change Log):
* etc/NEWS: Shorten docs for the new command.

1 files changed, 3 insertions, 3 deletions

diff --git a/doc/emacs/maintaining.texi b/doc/emacs/maintaining.texi
index 5af0c0f938a..2f8a15a0b0b 100644
--- a/doc/emacs/maintaining.texi
+++ b/doc/emacs/maintaining.texi
@@ -1245,9 +1245,9 @@ earlier revision (@code{log-view-diff-changeset}).  This shows the
 changes to all files made in that revision.
 
 @item w
-Copy the revision of the marked log entries into the kill ring, as if
-you had killed them with @kbd{M-w}.  Multiple entries will be separated
-by a space.
+Copy the revision of the log entry at point, or all marked revisions, to
+the kill ring, as if you had used @kbd{M-w}
+(@code{log-view-copy-revision-as-kill}).
 
 @item @key{RET}
 In a compact-style log buffer (e.g., the one created by @kbd{C-x v L}),