Subject: Re: bug#2652: 23.0.91; wacky behavior of "v" command in *vc-dir* buffer

From: Dan Nicolaescu <[email-masked]>
Date: Fri, 13 Mar 2009 09:22:10 -0700 (PDT)

Miles Bader <[email-masked]> writes:

  > On Fri, Mar 13, 2009 at 4:27 PM, Dan Nicolaescu <[email-masked]> wrote:
  > > Thanks.
  > > The immediate cause of the problem is that
  > > (vc-git-registered "/tmp/zonk/")
  > > returns nil.
  > >
  > > vc-git-registered is called because vc-finish-log-entry does a
  > > `vc-call'.  `vc-call' tries to find the corresponding VC backend.
  > >
  > > Now, the VC backend should be know known at point when the log entry is
  > > started, so there should be no need for the vc-call, vc-call-backend
  > > could be used...

You can try this patch that passes down the VC backend.  
Not tested beyond M-x byte-compile-file.

--- vc.el.~1.711.~	Thu Jan  8 14:24:05 2009
+++ vc.el	Fri Mar 13 09:14:58 2009
@@ -1085,13 +1085,13 @@
 	(if (not ready-for-commit)
 	    (message "No files remain to be committed")
 	  (if (not verbose)
-	      (vc-checkin ready-for-commit)
+	      (vc-checkin ready-for-commit backend)
 	    (progn
 	      (setq revision (read-string "New revision or backend: "))
 	      (let ((vsym (intern (upcase revision))))
 		(if (member vsym vc-handled-backends)
 		    (dolist (file files) (vc-transfer-file file vsym))
-		  (vc-checkin ready-for-commit revision))))))))
+		  (vc-checkin ready-for-commit backend revision))))))))
      ;; locked by somebody else (locking VCSes only)
      ((stringp state)
       ;; In the old days, we computed the revision once and used it on
@@ -1327,7 +1327,7 @@
      ".\n")
     (message "Please explain why you stole the lock.  Type C-c C-c when done.")))
 
-(defun vc-checkin (files &optional rev comment initial-contents)
+(defun vc-checkin (files backend &optional rev comment initial-contents)
   "Check in FILES.
 The optional argument REV may be a string specifying the new revision
 level (if nil increment the current level).  COMMENT is a comment
@@ -1341,6 +1341,7 @@
 Runs the normal hooks `vc-before-checkin-hook' and `vc-checkin-hook'."
   (when vc-before-checkin-hook
     (run-hooks 'vc-before-checkin-hook))
+  (lexical-let ((backend backend))
   (vc-start-logentry
    files rev comment initial-contents
    "Enter a change comment."
@@ -1356,13 +1357,13 @@
       ;; We used to change buffers to get local value of vc-checkin-switches,
       ;; but 'the' local buffer is not a well-defined concept for filesets.
       (progn
-	(vc-call checkin files rev comment)
+	(vc-call-backend backend 'checkin files rev comment)
 	(mapc 'vc-delete-automatic-version-backups files))
       `((vc-state . up-to-date)
 	(vc-checkout-time . ,(nth 5 (file-attributes file)))
 	(vc-working-revision . nil)))
      (message "Checking in %s...done" (vc-delistify files)))
-   'vc-checkin-hook))
+   'vc-checkin-hook)))
 
 ;;; Additional entry points for examining version histories
 
@@ -2096,7 +2097,7 @@
     (when (or move edited)
       (vc-file-setprop file 'vc-state 'edited)
       (vc-mode-line file)
-      (vc-checkin file nil comment (stringp comment)))))
+      (vc-checkin file new-backend nil comment (stringp comment)))))
 
 (defun vc-rename-master (oldmaster newfile templates)
   "Rename OLDMASTER to be the master file for NEWFILE based on TEMPLATES."