Re: vc-update for bzr etc.

[Dan Nicolaescu <dann@gnu.org>]

Chong Yidong <cyd@stupidchicken.com> writes:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>
>> VC tries to present a uniform UI and that is good, but trying to impose
>> a uniform semantics to all commands is asking too much.  So I think it's
>> perfectly OK for vc-pull/update to do "bzr pull" for Bzr and
>> "git pull" for Git, even if they don't do exactly the same thing.
>
> Fair enough.  Here's an updated patch.  I renamed the new operation
> vc-BACKEND-update-branch, and vc-update uses it preferentially if it
> exists (falling back on the old merge-news operation if not).  For
> vc-bzr-update-branch, it calls "bzr update" for bound branchs and
> "bzr pull" for other branches.  Passing a prefix arg to vc-update causes
> it to prompt for arguments to bzr.
>
> WDYT?

IMHO:
It looks like the future is pull/push.
If vc-pull is supported then vc-update can either use vc-pull directly
or just issue an error directing the users to use vc-pull. 
It does not look like a wise investment to go in the direction of
expanding support for vc-update.

>
>
> *** lisp/vc/vc-bzr.el	2010-11-09 20:07:10 +0000
> --- lisp/vc/vc-bzr.el	2010-11-22 04:29:26 +0000
> ***************
> *** 236,241 ****
> --- 236,280 ----
>       (when rootdir
>            (file-relative-name filename* rootdir))))
>   
> + (defun vc-bzr-update-branch (prompt)
> +   "Update the current Bzr branch.
> + If it is a bound branch, run \"bzr update\".
> + Otherwise, run \"bzr pull\"."
> +   (let* ((rootdir (vc-bzr-root default-directory))
> + 	 (bound ;; Whether the branch is bound.
> + 	  (with-temp-buffer
> + 	    (insert-file-contents
> + 	     (expand-file-name ".bzr/branch/branch.conf" rootdir))
> + 	    (goto-char (point-min))
> + 	    (re-search-forward "bound *= *True" nil t)))
> + 	 (command (if bound "update" "pull"))
> + 	 (vc-bzr-program vc-bzr-program)
> + 	 (args nil)
> + 	 buf)
> +     ;; If PROMPT is given, ask the user for the exact command.
> +     (when prompt
> +       (setq args
> + 	    (split-string
> + 	     (read-shell-command
> + 	      "Run bzr (like this): "
> + 	      (concat vc-bzr-program " " command))
> + 	     " " t))
> +       (if (< (length args) 2)
> + 	  (error "Invalid bzr command")
> + 	(setq vc-bzr-program (car args)
> + 	      command (nth 1 args)
> + 	      args (cddr args))))
> +     ;; Run asynchronously, ouputting to *vc-update* buffer.
> +     (setq buf (get-buffer-create "*vc-update*"))
> +     (with-current-buffer buf
> +       (goto-char (point-max))
> +       (unless (eq (point) (point-min))
> + 	(insert "\f\n"))
> +       (insert (format "Running \"%s %s\" for \"%s\"...\n"
> + 		      vc-bzr-program command rootdir))
> +       (vc-bzr-command command t 'async nil args))
> +     (display-buffer buf)))
> + 
>   (defun vc-bzr-status (file)
>     "Return FILE status according to Bzr.
>   Return value is a cons (STATUS . WARNING), where WARNING is a
>
> === modified file 'lisp/vc/vc.el'
> *** lisp/vc/vc.el	2010-11-12 13:44:46 +0000
> --- lisp/vc/vc.el	2010-11-22 03:56:27 +0000
> ***************
> *** 2274,2308 ****
>   (define-obsolete-function-alias 'vc-revert-buffer 'vc-revert "23.1")
>   
>   ;;;###autoload
> ! (defun vc-update ()
> !   "Update the current fileset's files to their tip revisions.
> ! For each one that contains no changes, and is not locked, then this simply
> ! replaces the work file with the latest revision on its branch.  If the file
> ! contains changes, and the backend supports merging news, then any recent
> ! changes from the current branch are merged into the working file."
> !   (interactive)
> !   (let* ((vc-fileset (vc-deduce-fileset))
>   	 (backend (car vc-fileset))
>   	 (files (cadr vc-fileset)))
> !     (save-some-buffers          ; save buffers visiting files
> !      nil (lambda ()
> !            (and (buffer-modified-p)
> !                 (let ((file (buffer-file-name)))
> !                   (and file (member file files))))))
> !     (dolist (file files)
> !       (if (vc-up-to-date-p file)
> ! 	  (vc-checkout file nil t)
> ! 	(if (eq (vc-checkout-model backend (list file)) 'locking)
> ! 	    (if (eq (vc-state file) 'edited)
> ! 		(error "%s"
> ! 		       (substitute-command-keys
> ! 			"File is locked--type \\[vc-revert] to discard changes"))
> ! 	      (error "Unexpected file state (%s) -- type %s"
> ! 		     (vc-state file)
> ! 		     (substitute-command-keys
> ! 		      "\\[vc-next-action] to correct")))
> !           (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.
> --- 2274,2320 ----
>   (define-obsolete-function-alias 'vc-revert-buffer 'vc-revert "23.1")
>   
>   ;;;###autoload
> ! (defun vc-update (&optional arg)
> !   "Update the current fileset or branch.
> ! On distributed version control systems, this updates the branch.
> ! With prefix ARG, prompt for an argument list for the command.
> ! 
> ! On all other version control systems, update the files in the
> ! current fileset to their tip revisions.  For each file that
> ! contains no changes, and is not locked, then this simply replaces
> ! the work file with the latest revision on its branch.  If the
> ! file contains changes, and the backend supports merging news,
> ! then any recent changes from the current branch are merged into
> ! the working file."
> !   (interactive "P")
> !   (when buffer-file-name (vc-buffer-sync t))
> !   (let* ((vc-fileset (vc-deduce-fileset t))
>   	 (backend (car vc-fileset))
>   	 (files (cadr vc-fileset)))
> !     (cond
> !      ;; If an update-branch operation is defined, use it.
> !      ((or arg (vc-find-backend-function backend 'update-branch))
> !       (vc-call-backend backend 'update-branch arg))
> !      ;; If VCS has `merge-news' functionality (CVS and SVN), use it.
> !      ((and (vc-find-backend-function backend 'merge-news)
> ! 	   (not arg))
> !       (save-some-buffers ; save buffers visiting files
> !        nil (lambda ()
> ! 	     (and (buffer-modified-p)
> ! 		  (let ((file (buffer-file-name)))
> ! 		    (and file (member file files))))))
> !       (dolist (file files)
> ! 	(if (vc-up-to-date-p file)
> ! 	    (vc-checkout file nil t)
> ! 	  (vc-maybe-resolve-conflicts
> ! 	   file (vc-call-backend backend 'merge-news file)))))
> !      ;; For a locking VCS, check out each file.
> !      ((eq (vc-checkout-model backend files) 'locking)
> !       (dolist (file files)
> ! 	(if (vc-up-to-date-p file)
> ! 	    (vc-checkout file nil t))))
> !      (t
> !       (error "VC update is unsupported for `%s'" backend)))))
>   
>   (defun vc-version-backup-file (file &optional rev)
>     "Return name of backup file for revision REV of FILE.