Re: 23.0.60; C-x v v in an ordinary file throws strange error

[Eric Hanchrow]

This sounds dimly familiar; I think the fix is to call buffer-live-p
instead of merely checking that the isn't nil (note that the following
three patches are somewhat disorganized; I think one patch obviates
another, but you get the idea):

    git show d92d80884f25a3d58d2a799c3426d498dadbc6a6
    commit d92d80884f25a3d58d2a799c3426d498dadbc6a6
    Author: Eric Hanchrow <address@hidden>
    Date:   Fri Feb 15 15:01:00 2008 -0800

        (and x (buffer-live-p x)) => (buffer-live-p x)

    diff --git a/lisp/vc.el b/lisp/vc.el
    index 584b58d..ec59361 100644
    --- a/lisp/vc.el
    +++ b/lisp/vc.el
    @@ -1354,8 +1354,7 @@ Otherwise, throw an error."
                  (list (vc-status-current-file)))))
            ((vc-backend buffer-file-name)
             (list buffer-file-name))
    -   ((and vc-parent-buffer
    -              (buffer-live-p vc-parent-buffer)
    +   ((and (buffer-live-p vc-parent-buffer)
                   (or (buffer-file-name vc-parent-buffer)
                       (with-current-buffer vc-parent-buffer
                         vc-dired-mode)))
    @@ -1389,8 +1388,7 @@ Otherwise, throw an error."
        ((eq major-mode 'vc-status-mode)
         (set-buffer (find-file-noselect (vc-status-current-file))))
        (t
    -    (while (and vc-parent-buffer
    -                (buffer-live-p vc-parent-buffer)
    +    (while (and (buffer-live-p vc-parent-buffer)
                    ;; Avoid infinite looping when vc-parent-buffer and
                    ;; current buffer are the same buffer.
                    (not (eq vc-parent-buffer (current-buffer))))
    07:36:29 address@hidden emacs-via-git]$ git show 
d20791cd96cf39e630e85b3b77cee4eb945a3783
    commit d20791cd96cf39e630e85b3b77cee4eb945a3783
    Author: Eric Hanchrow <address@hidden>
    Date:   Fri Feb 15 14:26:00 2008 -0800

        vc-deduce-fileset: similarly to dfbfd942, call buffer-live-p

    diff --git a/lisp/vc.el b/lisp/vc.el
    index 102eeef..584b58d 100644
    --- a/lisp/vc.el
    +++ b/lisp/vc.el
    @@ -1354,9 +1354,11 @@ Otherwise, throw an error."
                  (list (vc-status-current-file)))))
            ((vc-backend buffer-file-name)
             (list buffer-file-name))
    -   ((and vc-parent-buffer (or (buffer-file-name vc-parent-buffer)
    -                              (with-current-buffer vc-parent-buffer
    -                                vc-dired-mode)))
    +   ((and vc-parent-buffer
    +              (buffer-live-p vc-parent-buffer)
    +              (or (buffer-file-name vc-parent-buffer)
    +                  (with-current-buffer vc-parent-buffer
    +                    vc-dired-mode)))
             (progn
               (set-buffer vc-parent-buffer)
               (vc-deduce-fileset)))
    07:36:46 address@hidden emacs-via-git]$ git show dfbfd942
    commit dfbfd942a3c3e667a6f7b09f2d52f91e541a8b01
    Author: Stefan Monnier <address@hidden>
    Date:   Sun Jan 6 16:02:38 2008 +0000

        (vc-ensure-vc-buffer): Check liveness of vc-parent-buffer.

    diff --git a/lisp/ChangeLog b/lisp/ChangeLog
    index c8e3dc4..4a874b5 100644
    --- a/lisp/ChangeLog
    +++ b/lisp/ChangeLog
    @@ -1,3 +1,7 @@
    +2008-01-06  Stefan Monnier  <address@hidden>
    +
    +   * vc.el (vc-ensure-vc-buffer): Check liveness of vc-parent-buffer.
    +
     2008-01-06  Dan Nicolaescu  <address@hidden>

            * vc.el (vc-status-fileinfo): New defstruct.
    diff --git a/lisp/vc.el b/lisp/vc.el
    index 9e5df68..61a2c67 100644
    --- a/lisp/vc.el
    +++ b/lisp/vc.el
    @@ -1310,6 +1310,7 @@ Otherwise, throw an error."
       (if vc-dired-mode
           (set-buffer (find-file-noselect (dired-get-filename)))
         (while (and vc-parent-buffer
    +                (buffer-live-p vc-parent-buffer)
                    ;; Avoid infinite looping when vc-parent-buffer and
                    ;; current buffer are the same buffer.
                    (not (eq vc-parent-buffer (current-buffer))))

-- 
None of the ... actors do anything we couldn't do if we looked
like them.
        -- Roger Ebert, reviewing "The Chronicles Of Riddick"