make vc-annotate work through copies and renames

[Dan Nicolaescu <dann@ics.uci.edu>]

The annotate command on modern VC systems can work through file copies
and renames.
In case of a copy/rename the file name appears in the annotate output.
Here's an example from git (using the nicely named command line option -C -C),
annotating the f.csh file, which was copied from the t.csh file at some
point (file contents omitted here):

e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700  1) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700  2) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700  3) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700  4) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700  5) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700  6) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700  7) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700  8) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700  9) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 10) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 11) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 12) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 13) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 14) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 15) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 16) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 17) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 18) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 19) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 20) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 21) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 22) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 23) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 24) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 25) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 26) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 27) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 28) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 29) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 30) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 31) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 32) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 33) 
14d0ca93 t.csh (dann 2008-03-28 09:23:28 -0700 34) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700 35) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700 36) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700 37) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700 38) 
e19523a7 f.csh (dann 2009-07-31 23:53:36 -0700 39) 

vc-annotate.el assumes that the file name is always the same.  This is
not true when showing copies/renames.

One way to deal with this is to make
vc-annotate-extract-revision-at-line return a cons (REVISION . FILENAME)
instead of just REVISION.  Then work through all the commands and change
them to use the FILENAME that is passed.

Here's a patch that implements this, and it makes the "f" command work,
when run on lines 7...34 in the example above, it shows version
"14d0ca93" of t.csh.

Any suggestions?


--- vc-annotate.el.~1.9.~	2009-09-12 11:23:15.000000000 -0700
+++ vc-annotate.el	2009-10-14 05:18:09.000000000 -0700
@@ -432,7 +432,11 @@ revisions after."
 (defun vc-annotate-extract-revision-at-line ()
   "Extract the revision number of the current line."
   ;; This function must be invoked from a buffer in vc-annotate-mode
-  (vc-call-backend vc-annotate-backend 'annotate-extract-revision-at-line))
+  (let ((rev (vc-call-backend vc-annotate-backend
+			      'annotate-extract-revision-at-line)))
+    (if (or (null rev) (consp rev))
+	rev
+      (cons rev vc-annotate-parent-file))))
 
 (defun vc-annotate-revision-at-line ()
   "Visit the annotation of the revision identified in the current line."
@@ -442,9 +446,9 @@ revisions after."
     (let ((rev-at-line (vc-annotate-extract-revision-at-line)))
       (if (not rev-at-line)
 	  (message "Cannot extract revision number from the current line")
-	(if (equal rev-at-line vc-annotate-parent-rev)
+	(if (equal (car rev-at-line) vc-annotate-parent-rev)
 	    (message "Already at revision %s" rev-at-line)
-	  (vc-annotate-warp-revision rev-at-line))))))
+	  (vc-annotate-warp-revision (car rev-at-line) (cdr rev-at-line)))))))
 
 (defun vc-annotate-find-revision-at-line ()
   "Visit the revision identified in the current line."
@@ -454,7 +458,7 @@ revisions after."
     (let ((rev-at-line (vc-annotate-extract-revision-at-line)))
       (if (not rev-at-line)
 	  (message "Cannot extract revision number from the current line")
-	(vc-revision-other-window rev-at-line)))))
+	(switch-to-buffer-other-window (vc-find-revision  (cdr rev-at-line) (car rev-at-line)))))))
 
 (defun vc-annotate-revision-previous-to-line ()
   "Visit the annotation of the revision before the revision at line."
Index: vc-git.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/vc-git.el,v
retrieving revision 1.94
diff -u -3 -p -u -p -r1.94 vc-git.el
--- vc-git.el	20 Sep 2009 19:51:38 -0000	1.94
+++ vc-git.el	14 Oct 2009 13:47:54 -0000
@@ -613,7 +632,7 @@ or BRANCH^ (where \"^\" can be repeated)
 
 (defun vc-git-annotate-command (file buf &optional rev)
   (let ((name (file-relative-name file)))
-    (vc-git-command buf 'async name "blame" "--date=iso" rev "--")))
+    (vc-git-command buf 'async name "blame" "--date=iso" "-C" "-C" rev)))
 
 (declare-function vc-annotate-convert-time "vc-annotate" (time))
 
@@ -627,8 +646,11 @@ or BRANCH^ (where \"^\" can be repeated)
 (defun vc-git-annotate-extract-revision-at-line ()
   (save-excursion
     (move-beginning-of-line 1)
-    (and (looking-at "[0-9a-f^][0-9a-f]+")
-         (buffer-substring-no-properties (match-beginning 0) (match-end 0)))))
+    (when (looking-at "\\([0-9a-f^][0-9a-f]+\\) \\(\\([^(]+\\) \\)?")
+      (let ((revision (match-string-no-properties 1)))
+	(if (match-beginning 2)
+	  (cons revision (match-string-no-properties 3))
+	  revision)))))
 
 ;;; TAG SYSTEM