Make vc-annotate work through copies and renames.

* vc-annotate.el (vc-annotate-extract-revision-at-line): Return
the file name too.
(vc-annotate-revision-at-line)
(vc-annotate-find-revision-at-line)
(vc-annotate-revision-previous-to-line)
(vc-annotate-show-log-revision-at-line): Update to get the file
name from vc-annotate-extract-revision-at-line.
(vc-annotate-show-diff-revision-at-line-internal): Change the
argument to mean whether to show a file diff or not.  Get the file
name from vc-annotate-extract-revision-at-line.
(vc-annotate-show-diff-revision-at-line): Update
vc-annotate-show-diff-revision-at-line call.
(vc-annotate-warp-revision): Add an optional file argument.

* vc-git.el (vc-git-annotate-command): Pass -C -C to the blame command.
(vc-git-annotate-extract-revision-at-line): Also return the file
name if found.

* vc-hg.el (vc-hg-annotate-command): Pass --follow to the annotate
command.  Remove unused code.
(vc-hg-annotate-re): Update to match --follow output.
(vc-hg-annotate-extract-revision-at-line): Also return the file
name if found.

* vc.el: Update annotate-extract-revision-at-line documentation.

1 files changed, 3 insertions, 0 deletions

diff --git a/lisp/vc.el b/lisp/vc.el
index 87cade8485..2d5e325de2 100644
--- a/lisp/vc.el
+++ b/lisp/vc.el
@@ -418,6 +418,9 @@
 ;;   Invoked from a buffer in vc-annotate-mode, return the revision
 ;;   corresponding to the current line, or nil if there is no revision
 ;;   corresponding to the current line.
+;;   If the backend supports annotating through copies and renames,
+;;   and displays a file name and a revision, then return a cons
+;;   (REVISION . FILENAME).
 ;;
 ;; TAG SYSTEM
 ;;