* vc.el (vc-mark-resolved): Add `backend' argument.

(vc-next-action): Pass it the backend.
(vc-next-action, vc-checkout, vc-mark-resolved, vc-version-diff)
(vc-merge, vc-rollback, vc-update, vc-transfer-file, vc-delete-file)
(vc-default-comment-history, vc-default-create-snapshot)
(vc-default-retrieve-snapshot, vc-default-revert, vc-annotate)
(vc-annotate-revision-previous-to-line)
(vc-annotate-show-diff-revision-at-line, vc-annotate-warp-revision):
* vc-svn.el (vc-svn-checkout):
* vc-mcvs.el (vc-mcvs-checkout):
* vc-hooks.el (vc-state, vc-default-workfile-unchanged-p)
(vc-working-revision, vc-before-save, vc-mode-line):
Prefer vc-call-backend to vc-call so as not to recompute the backend.

5 files changed, 95 insertions, 67 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index bc21788653b..4b2d890ae41 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,12 +1,25 @@
 2008-05-09  Eric S. Raymond  <esr@snark.thyrsus.com>
 
-        * vc-scs.el (vc-sccs-checkin, vc-sccs-checkout, vc-sccs-rollback, 
-        vc-sccs-revert, vc-sccs-steal-lock, vc-sccs-modify-change-comment,
-        vc-sccs-print-log, vc-sccs-diff): Teach SCCS back end to grok 
-        directories.
+        * vc-scs.el (vc-sccs-checkin, vc-sccs-checkout, vc-sccs-rollback)
+        (vc-sccs-revert, vc-sccs-steal-lock, vc-sccs-modify-change-comment)
+        (vc-sccs-print-log, vc-sccs-diff): Grok directories.
 
 2008-05-09  Stefan Monnier  <monnier@iro.umontreal.ca>
 
+        * vc.el (vc-mark-resolved): Add `backend' argument.
+        (vc-next-action): Pass it the backend.
+        (vc-next-action, vc-checkout, vc-mark-resolved, vc-version-diff)
+        (vc-merge, vc-rollback, vc-update, vc-transfer-file, vc-delete-file)
+        (vc-default-comment-history, vc-default-create-snapshot)
+        (vc-default-retrieve-snapshot, vc-default-revert, vc-annotate)
+        (vc-annotate-revision-previous-to-line)
+        (vc-annotate-show-diff-revision-at-line, vc-annotate-warp-revision):
+        * vc-svn.el (vc-svn-checkout):
+        * vc-mcvs.el (vc-mcvs-checkout):
+        * vc-hooks.el (vc-state, vc-default-workfile-unchanged-p)
+        (vc-working-revision, vc-before-save, vc-mode-line):
+        Prefer vc-call-backend to vc-call so as not to recompute the backend.
+
         * vc.el (vc-deduce-fileset): Don't require the checkout-model and the
         state to be consistent since it's often an unwarranted restriction.
         Don't return the state either.
diff --git a/lisp/vc-hooks.el b/lisp/vc-hooks.el
index 86cce60f27f..926027bdff3 100644
--- a/lisp/vc-hooks.el
+++ b/lisp/vc-hooks.el
@@ -539,9 +539,12 @@ status of this file."
   ;; - `removed'
   ;; - `copied' and `moved' (might be handled by `removed' and `added')
   (or (vc-file-getprop file 'vc-state)
-      (when (and (> (length file) 0) (vc-backend file))
-        (vc-file-setprop file 'vc-state
-                         (vc-call state-heuristic file)))))
+      (when (> (length file) 0)
+        (let ((backend (vc-backend file)))
+          (when backend
+            (vc-file-setprop
+             file 'vc-state
+             (vc-call-backend backend 'state-heuristic file)))))))
 
 (defun vc-recompute-state (file)
   "Recompute the version control state of FILE, and return it.
@@ -577,26 +580,26 @@ Return non-nil if FILE is unchanged."
   (zerop (condition-case err
              ;; If the implementation supports it, let the output
              ;; go to *vc*, not *vc-diff*, since this is an internal call.
-             (vc-call diff (list file) nil nil "*vc*")
+             (vc-call-backend backend 'diff (list file) nil nil "*vc*")
            (wrong-number-of-arguments
             ;; If this error came from the above call to vc-BACKEND-diff,
             ;; try again without the optional buffer argument (for
             ;; backward compatibility).  Otherwise, resignal.
             (if (or (not (eq (cadr err)
                              (indirect-function
-                              (vc-find-backend-function (vc-backend file)
-                                                        'diff))))
+                              (vc-find-backend-function backend 'diff))))
                     (not (eq (caddr err) 4)))
                 (signal (car err) (cdr err))
-              (vc-call diff (list file)))))))
+              (vc-call-backend backend 'diff (list file)))))))
 
 (defun vc-working-revision (file)
   "Return the repository version from which FILE was checked out.
 If FILE is not registered, this function always returns nil."
   (or (vc-file-getprop file 'vc-working-revision)
-      (when (vc-backend file)
-        (vc-file-setprop file 'vc-working-revision
-                         (vc-call working-revision file)))))
+      (let ((backend (vc-backend file)))
+        (when backend
+          (vc-file-setprop file 'vc-working-revision
+                           (vc-call-backend backend 'working-revision file))))))
 
 ;; Backward compatibility.
 (define-obsolete-function-alias
@@ -746,7 +749,7 @@ Before doing that, check if there are any old backups and get rid of them."
       (and (setq backend (vc-backend file))
            (vc-up-to-date-p file)
            (eq (vc-checkout-model backend (list file)) 'implicit)
-           (vc-call make-version-backups-p file)
+           (vc-call-backend backend 'make-version-backups-p file)
            (vc-make-version-backup file)))))
 
 (declare-function vc-directory-resynch-file "vc" (file))
@@ -798,7 +801,7 @@ visiting FILE."
   (let ((backend (vc-backend file)))
     (if (not backend)
         (setq vc-mode nil)
-      (let* ((ml-string (vc-call mode-line-string file))
+      (let* ((ml-string (vc-call-backend backend 'mode-line-string file))
              (ml-echo (get-text-property 0 'help-echo ml-string)))
         (setq vc-mode
               (concat
diff --git a/lisp/vc-mcvs.el b/lisp/vc-mcvs.el
index 9eb91503089..7bef11c2401 100644
--- a/lisp/vc-mcvs.el
+++ b/lisp/vc-mcvs.el
@@ -312,7 +312,7 @@ This is only possible if Meta-CVS is responsible for FILE's directory.")
 (defun vc-mcvs-checkout (file &optional editable rev)
   (message "Checking out %s..." file)
   (with-current-buffer (or (get-file-buffer file) (current-buffer))
-    (vc-call update file editable rev (vc-switches 'MCVS 'checkout)))
+    (vc-mcvs-update file editable rev (vc-switches 'MCVS 'checkout)))
   (vc-mode-line file)
   (message "Checking out %s...done" file))
 
diff --git a/lisp/vc-svn.el b/lisp/vc-svn.el
index b08f050fd55..49c4c4153e6 100644
--- a/lisp/vc-svn.el
+++ b/lisp/vc-svn.el
@@ -271,7 +271,7 @@ This is only possible if SVN is responsible for FILE's directory.")
 (defun vc-svn-checkout (file &optional editable rev)
   (message "Checking out %s..." file)
   (with-current-buffer (or (get-file-buffer file) (current-buffer))
-    (vc-call update file editable rev (vc-switches 'SVN 'checkout)))
+    (vc-svn-update file editable rev (vc-switches 'SVN 'checkout)))
   (vc-mode-line file)
   (message "Checking out %s...done" file))
 
diff --git a/lisp/vc.el b/lisp/vc.el
index 8c8394e6fa9..052ee7ce9e1 100644
--- a/lisp/vc.el
+++ b/lisp/vc.el
@@ -1193,7 +1193,12 @@ merge in the changes into your working copy."
          state)))
      ;; conflict
      ((eq state 'conflict)
-      (vc-mark-resolved files))
+      ;; FIXME: Is it really the UI we want to provide?
+      ;; In my experience, the conflicted files should be marked as resolved
+      ;; one-by-one when saving the file after resolving the conflicts.
+      ;; I.e. stating explicitly that the conflicts are resolved is done
+      ;; very rarely.
+      (vc-mark-resolved backend files))
      ;; needs-update
      ((eq state 'needs-update)
       (dolist (file files)
@@ -1210,7 +1215,8 @@ merge in the changes into your working copy."
         (when (yes-or-no-p (format
                           "%s is not up-to-date.  Merge in changes now? "
                           (file-name-nondirectory file)))
-          (vc-maybe-resolve-conflicts file (vc-call merge-news file)))))
+          (vc-maybe-resolve-conflicts
+           file (vc-call-backend backend 'merge-news file)))))
 
      ;; unlocked-changes
      ((eq state 'unlocked-changes)
@@ -1228,7 +1234,7 @@ merge in the changes into your working copy."
               (not (beep))
               (yes-or-no-p (concat "File has unlocked changes.  "
                                    "Claim lock retaining changes? ")))
-            (progn (vc-call steal-lock file)
+            (progn (vc-call-backend backend 'steal-lock file)
                    (clear-visited-file-modtime)
                    ;; Must clear any headers here because they wouldn't
                    ;; show that the file is locked now.
@@ -1340,7 +1346,7 @@ After check-out, runs the normal hook `vc-checkout-hook'."
          (signal (car err) (cdr err))))
       `((vc-state . ,(if (or (eq (vc-checkout-model backend (list file)) 'implicit)
                              (not writable))
-                         (if (vc-call latest-on-branch-p file)
+                         (if (vc-call-backend backend 'latest-on-branch-p file)
                              'up-to-date
                            'needs-update)
                        'edited))
@@ -1348,10 +1354,10 @@ After check-out, runs the normal hook `vc-checkout-hook'."
   (vc-resynch-buffer file t t)
   (run-hooks 'vc-checkout-hook))
 
-(defun vc-mark-resolved (files)
+(defun vc-mark-resolved (backend files)
   (with-vc-properties
    files
-   (vc-call mark-resolved files)
+   (vc-call-backend backend 'mark-resolved files)
    ;; XXX: Is this TRTD?  Might not be.
    `((vc-state . edited))))
 
@@ -1564,9 +1570,10 @@ returns t if the buffer had changes, nil otherwise."
   (interactive
    (let* ((vc-fileset (vc-deduce-fileset))
           (files (cdr vc-fileset))
+          (backend (car vc-fileset))
           (first (car files))
           (completion-table
-           (vc-call revision-completion-table files))
+           (vc-call-backend backend 'revision-completion-table files))
           (rev1-default nil)
           (rev2-default nil))
      (cond
@@ -1582,8 +1589,8 @@ returns t if the buffer had changes, nil otherwise."
        (setq rev1-default (vc-working-revision first)))
       ;; if the file is not locked, use last and previous revisions as defaults
       (t
-       (setq rev1-default (vc-call previous-revision first
-                                   (vc-working-revision first)))
+       (setq rev1-default (vc-call-backend backend 'previous-revision first
+                                           (vc-working-revision first)))
        (when (string= rev1-default "") (setq rev1-default nil))
        (setq rev2-default (vc-working-revision first))))
      ;; construct argument list
@@ -1774,9 +1781,7 @@ See Info node `Merging'."
           (read-string (concat "Branch or revision to merge from "
                                "(default news on current branch): ")))
     (if (string= first-revision "")
-        (if (not (vc-find-backend-function backend 'merge-news))
-            (error "Sorry, merging news is not implemented for %s" backend)
-          (setq status (vc-call merge-news file)))
+        (setq status (vc-call-backend backend 'merge-news file))
       (if (not (vc-find-backend-function backend 'merge))
           (error "Sorry, merging is not implemented for %s" backend)
         (if (not (vc-branch-p first-revision))
@@ -1788,7 +1793,8 @@ See Info node `Merging'."
           (setq second-revision first-revision)
           ;; first-revision must be the starting point of the branch
           (setq first-revision (vc-branch-part first-revision)))
-        (setq status (vc-call merge file first-revision second-revision))))
+        (setq status (vc-call-backend backend 'merge file
+                                      first-revision second-revision))))
     (vc-maybe-resolve-conflicts file status "WORKFILE" "MERGE SOURCE")))
 
 (defun vc-maybe-resolve-conflicts (file status &optional name-A name-B)
@@ -2192,7 +2198,8 @@ depending on the underlying version-control system."
       (error "Rollback is not supported in %s" backend))
     (when (and (not (eq granularity 'repository)) (/= (length files) 1))
       (error "Rollback requires a singleton fileset or repository versioning"))
-    (when (not (vc-call latest-on-branch-p (car files)))
+    ;; FIXME: latest-on-branch-p should take the fileset.
+    (when (not (vc-call-backend backend 'latest-on-branch-p (car files)))
       (error "Rollback is only possible at the tip revision."))
     ;; If any of the files is visited by the current buffer, make
     ;; sure buffer is saved.  If the user says `no', abort since
@@ -2210,7 +2217,9 @@ depending on the underlying version-control system."
     (not-modified)
     (message "Finding changes...")
     (let* ((tip (vc-working-revision (car files)))
-           (previous (vc-call previous-revision (car files) tip)))
+           ;; FIXME: `previous-revision' should take the fileset.
+           (previous (vc-call-backend backend 'previous-revision
+                                      (car files) tip)))
       (vc-diff-internal nil vc-fileset previous tip))
     ;; Display changes
     (unless (yes-or-no-p "Discard these revisions? ")
@@ -2257,10 +2266,8 @@ changes from the current branch are merged into the working file."
                      (vc-state file)
                      (substitute-command-keys
                       "\\[vc-next-action] to correct")))
-          (if (not (vc-find-backend-function backend 'merge-news))
-              (error "Sorry, merging news is not implemented for %s"
-                     backend)
-            (vc-maybe-resolve-conflicts file (vc-call merge-news file))))))))
+          (vc-maybe-resolve-conflicts
+           file (vc-call-backend backend 'merge-news file)))))))
 
 (defun vc-version-backup-file (file &optional rev)
   "Return name of backup file for revision REV of FILE.
@@ -2381,8 +2388,8 @@ backend to NEW-BACKEND, and unregister FILE from the current backend.
             (vc-file-setprop file 'vc-checkout-time nil)))))
     (when move
       (vc-switch-backend file old-backend)
-      (setq comment (vc-call comment-history file))
-      (vc-call unregister file))
+      (setq comment (vc-call-backend old-backend 'comment-history file))
+      (vc-call-backend old-backend 'unregister file))
     (vc-switch-backend file new-backend)
     (when (or move edited)
       (vc-file-setprop file 'vc-state 'edited)
@@ -2446,7 +2453,7 @@ backend to NEW-BACKEND, and unregister FILE from the current backend.
         ;; command, kill the buffer created by the above
         ;; `find-file-noselect' call.
         (unless buf (kill-buffer (current-buffer)))))
-    (vc-call delete-file file)
+    (vc-call-backend backend 'delete-file file)
     ;; If the backend hasn't deleted the file itself, let's do it for him.
     (when (file-exists-p file) (delete-file file))
     ;; Forget what VC knew about the file.
@@ -2701,7 +2708,7 @@ to provide the `find-revision' operation instead."
   "Return a string with all log entries stored in BACKEND for FILE."
   (when (vc-find-backend-function backend 'print-log)
     (with-current-buffer "*vc*"
-      (vc-call print-log (list file))
+      (vc-call-backend backend 'print-log (list file))
       (vc-call-backend backend 'wash-log)
       (buffer-string))))
 
@@ -2718,7 +2725,7 @@ to provide the `find-revision' operation instead."
       (vc-file-tree-walk
        dir
        (lambda (f)
-         (vc-call assign-name f name))))))
+         (vc-call-backend backend 'assign-name f name))))))
 
 (defun vc-default-retrieve-snapshot (backend dir name update)
   (if (string= name "")
@@ -2728,7 +2735,7 @@ to provide the `find-revision' operation instead."
          (lambda (f) (and
                  (vc-up-to-date-p f)
                  (vc-error-occurred
-                  (vc-call checkout f nil "")
+                  (vc-call-backend backend 'checkout f nil "")
                   (when update (vc-resynch-buffer f t t)))))))
     (let ((result (vc-snapshot-precondition dir)))
       (if (stringp result)
@@ -2737,7 +2744,7 @@ to provide the `find-revision' operation instead."
         (vc-file-tree-walk
          dir
          (lambda (f) (vc-error-occurred
-                 (vc-call checkout f nil name)
+                 (vc-call-backend backend 'checkout f nil name)
                  (when update (vc-resynch-buffer f t t)))))))))
 
 (defun vc-default-revert (backend file contents-done)
@@ -2759,7 +2766,8 @@ to provide the `find-revision' operation instead."
                   ;; Change buffer to get local value of vc-checkout-switches.
                   (with-current-buffer file-buffer
                     (let ((default-directory (file-name-directory file)))
-                      (vc-call find-revision file rev outbuf)))))
+                      (vc-call-backend backend 'find-revision
+                                       file rev outbuf)))))
               (setq failed nil))
           (when backup-name
             (if failed
@@ -3015,18 +3023,20 @@ mode-specific menu.  `vc-annotate-color-map' and
                 ;; In case it had to be uniquified.
                 (setq temp-buffer-name (buffer-name))))
     (with-output-to-temp-buffer temp-buffer-name
-      (vc-call annotate-command file (get-buffer temp-buffer-name) rev)
-      ;; we must setup the mode first, and then set our local
-      ;; variables before the show-function is called at the exit of
-      ;; with-output-to-temp-buffer
-      (with-current-buffer temp-buffer-name
-        (unless (equal major-mode 'vc-annotate-mode)
-          (vc-annotate-mode))
-        (set (make-local-variable 'vc-annotate-backend) (vc-backend file))
-        (set (make-local-variable 'vc-annotate-parent-file) file)
-        (set (make-local-variable 'vc-annotate-parent-rev) rev)
-        (set (make-local-variable 'vc-annotate-parent-display-mode)
-             display-mode)))
+      (let ((backend (vc-backend file)))
+        (vc-call-backend backend 'annotate-command file
+                         (get-buffer temp-buffer-name) rev)
+        ;; we must setup the mode first, and then set our local
+        ;; variables before the show-function is called at the exit of
+        ;; with-output-to-temp-buffer
+        (with-current-buffer temp-buffer-name
+          (unless (equal major-mode 'vc-annotate-mode)
+            (vc-annotate-mode))
+          (set (make-local-variable 'vc-annotate-backend) backend)
+          (set (make-local-variable 'vc-annotate-parent-file) file)
+          (set (make-local-variable 'vc-annotate-parent-rev) rev)
+          (set (make-local-variable 'vc-annotate-parent-display-mode)
+               display-mode))))
 
     (with-current-buffer temp-buffer-name
       (vc-exec-after
@@ -3103,7 +3113,8 @@ revisions after."
       (if (not rev-at-line)
           (message "Cannot extract revision number from the current line")
         (setq prev-rev
-              (vc-call previous-revision vc-annotate-parent-file rev-at-line))
+              (vc-call-backend vc-annotate-backend 'previous-revision
+                               vc-annotate-parent-file rev-at-line))
         (vc-annotate-warp-revision prev-rev)))))
 
 (defun vc-annotate-show-log-revision-at-line ()
@@ -3126,7 +3137,8 @@ revisions after."
       (if (not rev-at-line)
           (message "Cannot extract revision number from the current line")
         (setq prev-rev
-              (vc-call previous-revision vc-annotate-parent-file rev-at-line))
+              (vc-call-backend vc-annotate-backend 'previous-revision
+                               vc-annotate-parent-file rev-at-line))
         (if (not prev-rev)
             (message "Cannot diff from any revision prior to %s" rev-at-line)
           (save-window-excursion
@@ -3157,18 +3169,18 @@ revision."
        ((and (integerp revspec) (> revspec 0))
         (setq newrev vc-annotate-parent-rev)
         (while (and (> revspec 0) newrev)
-               (setq newrev (vc-call next-revision
-                                     vc-annotate-parent-file newrev))
-               (setq revspec (1- revspec)))
+          (setq newrev (vc-call-backend vc-annotate-backend 'next-revision
+                                        vc-annotate-parent-file newrev))
+          (setq revspec (1- revspec)))
         (unless newrev
           (message "Cannot increment %d revisions from revision %s"
                    revspeccopy vc-annotate-parent-rev)))
        ((and (integerp revspec) (< revspec 0))
         (setq newrev vc-annotate-parent-rev)
         (while (and (< revspec 0) newrev)
-               (setq newrev (vc-call previous-revision
-                                     vc-annotate-parent-file newrev))
-               (setq revspec (1+ revspec)))
+          (setq newrev (vc-call-backend vc-annotate-backend 'previous-revision
+                                        vc-annotate-parent-file newrev))
+          (setq revspec (1+ revspec)))
         (unless newrev
           (message "Cannot decrement %d revisions from revision %s"
                    (- 0 revspeccopy) vc-annotate-parent-rev)))
@@ -3181,8 +3193,8 @@ revision."
                      ;; Pass the current line so that vc-annotate will
                      ;; place the point in the line.
                      (min oldline (progn (goto-char (point-max))
-                                           (forward-line -1)
-                                           (line-number-at-pos))))))))
+                                         (forward-line -1)
+                                         (line-number-at-pos))))))))
 
 (defun vc-annotate-compcar (threshold a-list)
   "Test successive cons cells of A-LIST against THRESHOLD.