code.delx.au - gnu-emacs/blob - lisp/vc-rcs.el

   1 ;;; vc-rcs.el --- support for RCS version-control
   2
   3 ;; Copyright (C) 1992,93,94,95,96,97,98,99,2000  Free Software Foundation, Inc.
   4
   5 ;; Author:     FSF (see vc.el for full credits)
   6 ;; Maintainer: Andre Spiegel <spiegel@gnu.org>
   7
   8 ;; $Id: vc-rcs.el,v 1.3 2000/09/07 20:02:38 fx Exp $
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:   see vc.el
  28
  29 ;;; Code:
  30
  31 (defcustom vc-rcs-release nil
  32   "*The release number of your RCS installation, as a string.
  33 If nil, VC itself computes this value when it is first needed."
  34   :type '(choice (const :tag "Auto" nil)
  35                  (string :tag "Specified")
  36                  (const :tag "Unknown" unknown))
  37   :group 'vc)
  38
  39 (defcustom vc-rcs-register-switches nil
  40   "*Extra switches for registering a file in RCS.
  41 A string or list of strings.  These are passed to the checkin program
  42 by \\[vc-rcs-register]."
  43   :type '(choice (const :tag "None" nil)
  44                  (string :tag "Argument String")
  45                  (repeat :tag "Argument List"
  46                          :value ("")
  47                          string))
  48   :version "21.1"
  49   :group 'vc)
  50
  51 (defcustom vc-rcs-checkin-switches nil
  52   "*A string or list of strings specifying extra switches for RCS checkin.
  53 These are passed to the checkin program by \\[vc-rcs-checkin]."
  54   :type '(choice (const :tag "None" nil)
  55                  (string :tag "Argument String")
  56                  (repeat :tag "Argument List"
  57                          :value ("")
  58                          string))
  59   :version "21.1"
  60   :group 'vc)
  61
  62 (defcustom vc-rcs-checkout-switches nil
  63   "*A string or list of strings specifying extra switches for RCS checkout.
  64 These are passed to the checkout program by \\[vc-rcs-checkout]."
  65   :type '(choice (const :tag "None" nil)
  66                  (string :tag "Argument String")
  67                  (repeat :tag "Argument List"
  68                          :value ("")
  69                          string))
  70   :version "21.1"
  71   :group 'vc)
  72
  73 (defcustom vc-rcs-header (or (cdr (assoc 'RCS vc-header-alist)) '("\$Id\$"))
  74   "*Header keywords to be inserted by `vc-insert-headers'."
  75   :type 'string
  76   :version "21.1"
  77   :group 'vc)
  78
  79 (defcustom vc-rcsdiff-knows-brief nil
  80   "*Indicates whether rcsdiff understands the --brief option.
  81 The value is either `yes', `no', or nil.  If it is nil, VC tries
  82 to use --brief and sets this variable to remember whether it worked."
  83   :type '(choice (const :tag "Work out" nil) (const yes) (const no))
  84   :group 'vc)
  85
  86 ;;;###autoload
  87 (defcustom vc-rcs-master-templates
  88   '("%sRCS/%s,v" "%s%s,v" "%sRCS/%s")
  89   "*Where to look for RCS master files.
  90 For a description of possible values, see `vc-check-master-templates'."
  91   :type '(choice (const :tag "Use standard RCS file names"
  92                         '("%sRCS/%s,v" "%s%s,v" "%sRCS/%s"))
  93                  (repeat :tag "User-specified"
  94                          (choice string
  95                                  function)))
  96   :version "21.1"
  97   :group 'vc)
  98
  99 ;;;###autoload
 100 (progn (defun vc-rcs-registered (f) (vc-default-registered 'RCS f)))
 101
 102 (defun vc-rcs-state (file)
 103   "Implementation of `vc-state' for RCS."
 104   (or (boundp 'vc-rcs-headers-result)
 105       (and vc-consult-headers
 106            (vc-rcs-consult-headers file)))
 107   (let ((state
 108          ;; vc-workfile-version might not be known; in that case the
 109          ;; property is nil.  vc-rcs-fetch-master-state knows how to
 110          ;; handle that.
 111          (vc-rcs-fetch-master-state file
 112                                     (vc-file-getprop file
 113                                                      'vc-workfile-version))))
 114     (if (eq state 'up-to-date)
 115         (if (vc-workfile-unchanged-p file)
 116             'up-to-date
 117           'unlocked-changes)
 118       state)))
 119
 120 (defun vc-rcs-state-heuristic (file)
 121   "State heuristic for RCS."
 122   (let (vc-rcs-headers-result)
 123     (if (and vc-consult-headers
 124              (setq vc-rcs-headers-result
 125                    (vc-rcs-consult-headers file))
 126              (eq vc-rcs-headers-result 'rev-and-lock))
 127         (let ((state (vc-file-getprop file 'vc-state)))
 128           ;; If the headers say that the file is not locked, the
 129           ;; permissions can tell us whether locking is used for
 130           ;; the file or not.
 131           (if (and (eq state 'up-to-date)
 132                    (not (vc-mistrust-permissions file)))
 133               (cond
 134                ((string-match ".rw..-..-." (nth 8 (file-attributes file)))
 135                 (vc-file-setprop file 'vc-checkout-model 'implicit))
 136                ((string-match ".r-..-..-." (nth 8 (file-attributes file)))
 137                 (vc-file-setprop file 'vc-checkout-model 'locking))))
 138           state)
 139       (if (not (vc-mistrust-permissions file))
 140           (let* ((attributes  (file-attributes file))
 141                  (owner-uid   (nth 2 attributes))
 142                  (permissions (nth 8 attributes)))
 143             (cond ((string-match ".r-..-..-." permissions)
 144                    (vc-file-setprop file 'vc-checkout-model 'locking)
 145                    'up-to-date)
 146                   ((string-match ".rw..-..-." permissions)
 147                    (if (file-ownership-preserved-p file)
 148                        'edited
 149                      (vc-user-login-name owner-uid)))
 150                   (t
 151                    ;; Strange permissions.  Fall through to
 152                    ;; expensive state computation.
 153                    (vc-rcs-state file))))
 154         (vc-rcs-state file)))))
 155
 156 (defun vc-rcs-workfile-version (file)
 157   "RCS-specific version of `vc-workfile-version'."
 158   (or (and vc-consult-headers
 159            (vc-rcs-consult-headers file)
 160            (vc-file-getprop file 'vc-workfile-version))
 161       (progn
 162         (vc-rcs-fetch-master-state file)
 163         (vc-file-getprop file 'vc-workfile-version))))
 164
 165 (defun vc-rcs-checkout-model (file)
 166   "RCS-specific version of `vc-checkout-model'."
 167   (vc-rcs-consult-headers file)
 168   (or (vc-file-getprop file 'vc-checkout-model)
 169       (progn (vc-rcs-fetch-master-state file)
 170              (vc-file-getprop file 'vc-checkout-model))))
 171
 172 ;;; internal code
 173
 174 (defun vc-rcs-find-most-recent-rev (branch)
 175   "Find most recent revision on BRANCH."
 176   (goto-char (point-min))
 177   (let ((latest-rev -1) value)
 178     (while (re-search-forward (concat "^\\(" (regexp-quote branch)
 179                                       "\\.\\([0-9]+\\)\\)\ndate[ \t]+[0-9.]+;")
 180                               nil t)
 181       (let ((rev (string-to-number (match-string 2))))
 182         (when (< latest-rev rev)
 183           (setq latest-rev rev)
 184           (setq value (match-string 1)))))
 185     value))
 186
 187 (defun vc-rcs-fetch-master-state (file &optional workfile-version)
 188   "Compute the master file's idea of the state of FILE.
 189 If a WORKFILE-VERSION is given, compute the state of that version,
 190 otherwise determine the workfile version based on the master file.
 191 This function sets the properties `vc-workfile-version' and
 192 `vc-checkout-model' to their correct values, based on the master
 193 file."
 194   (with-temp-buffer
 195     (vc-insert-file (vc-name file) "^[0-9]")
 196     (let ((workfile-is-latest nil))
 197       (unless workfile-version
 198         (let ((default-branch (vc-parse-buffer "^branch[ \t\n]+\\([^;]*\\);" 1)))
 199           ;; Workfile version not known yet.  Determine that first.  It
 200           ;; is either the head of the trunk, the head of the default
 201           ;; branch, or the "default branch" itself, if that is a full
 202           ;; revision number.
 203           (cond
 204            ;; no default branch
 205            ((or (not default-branch) (string= "" default-branch))
 206             (setq workfile-version
 207                   (vc-parse-buffer "^head[ \t\n]+\\([^;]+\\);" 1))
 208             (setq workfile-is-latest t))
 209            ;; default branch is actually a revision
 210            ((string-match "^[0-9]+\\.[0-9]+\\(\\.[0-9]+\\.[0-9]+\\)*$"
 211                           default-branch)
 212             (setq workfile-version default-branch))
 213            ;; else, search for the head of the default branch
 214            (t (vc-insert-file (vc-name file) "^desc")
 215               (setq workfile-version
 216                     (vc-rcs-find-most-recent-rev default-branch))
 217               (setq workfile-is-latest t)))
 218           (vc-file-setprop file 'vc-workfile-version workfile-version)))
 219       ;; Check strict locking
 220       (goto-char (point-min))
 221       (vc-file-setprop file 'vc-checkout-model
 222                        (if (re-search-forward ";[ \t\n]*strict;" nil t)
 223                            'locking 'implicit))
 224       ;; Compute state of workfile version
 225       (goto-char (point-min))
 226       (let ((locking-user
 227              (vc-parse-buffer (concat "^locks[ \t\n]+[^;]*[ \t\n]+\\([^:]+\\):"
 228                                       (regexp-quote workfile-version)
 229                                       "[^0-9.]")
 230                               1)))
 231         (cond
 232          ;; not locked
 233          ((not locking-user)
 234           (if (or workfile-is-latest
 235                   (vc-rcs-latest-on-branch-p file workfile-version))
 236               ;; workfile version is latest on branch
 237               'up-to-date
 238             ;; workfile version is not latest on branch
 239             'needs-patch))
 240          ;; locked by the calling user
 241          ((and (stringp locking-user)
 242                (string= locking-user (vc-user-login-name)))
 243           (if (or (eq (vc-checkout-model file) 'locking)
 244                   workfile-is-latest
 245                   (vc-rcs-latest-on-branch-p file workfile-version))
 246               'edited
 247             ;; Locking is not used for the file, but the owner does
 248             ;; have a lock, and there is a higher version on the current
 249             ;; branch.  Not sure if this can occur, and if it is right
 250             ;; to use `needs-merge' in this case.
 251             'needs-merge))
 252          ;; locked by somebody else
 253          ((stringp locking-user)
 254           locking-user)
 255          (t
 256           (error "Error getting state of RCS file")))))))
 257
 258 (defun vc-rcs-consult-headers (file)
 259   "Search for RCS headers in FILE, and set properties accordingly.
 260
 261 Returns: nil            if no headers were found
 262          'rev           if a workfile revision was found
 263          'rev-and-lock  if revision and lock info was found"
 264   (cond
 265    ((not (get-file-buffer file)) nil)
 266    ((let (status version locking-user)
 267      (save-excursion
 268       (set-buffer (get-file-buffer file))
 269       (goto-char (point-min))
 270       (cond
 271        ;; search for $Id or $Header
 272        ;; -------------------------
 273        ;; The `\ 's below avoid an RCS 5.7 bug when checking in this file.
 274        ((or (and (search-forward "$Id\ : " nil t)
 275                  (looking-at "[^ ]+ \\([0-9.]+\\) "))
 276             (and (progn (goto-char (point-min))
 277                         (search-forward "$Header\ : " nil t))
 278                  (looking-at "[^ ]+ \\([0-9.]+\\) ")))
 279         (goto-char (match-end 0))
 280         ;; if found, store the revision number ...
 281         (setq version (match-string-no-properties 1))
 282         ;; ... and check for the locking state
 283         (cond
 284          ((looking-at
 285            (concat "[0-9]+[/-][01][0-9][/-][0-3][0-9] "             ; date
 286             "[0-2][0-9]:[0-5][0-9]+:[0-6][0-9]+\\([+-][0-9:]+\\)? " ; time
 287                    "[^ ]+ [^ ]+ "))                       ; author & state
 288           (goto-char (match-end 0)) ; [0-6] in regexp handles leap seconds
 289           (cond
 290            ;; unlocked revision
 291            ((looking-at "\\$")
 292             (setq locking-user 'none)
 293             (setq status 'rev-and-lock))
 294            ;; revision is locked by some user
 295            ((looking-at "\\([^ ]+\\) \\$")
 296             (setq locking-user (match-string-no-properties 1))
 297             (setq status 'rev-and-lock))
 298            ;; everything else: false
 299            (nil)))
 300          ;; unexpected information in
 301          ;; keyword string --> quit
 302          (nil)))
 303        ;; search for $Revision
 304        ;; --------------------
 305        ((re-search-forward (concat "\\$"
 306                                    "Revision: \\([0-9.]+\\) \\$")
 307                            nil t)
 308         ;; if found, store the revision number ...
 309         (setq version (match-string-no-properties 1))
 310         ;; and see if there's any lock information
 311         (goto-char (point-min))
 312         (if (re-search-forward (concat "\\$" "Locker:") nil t)
 313             (cond ((looking-at " \\([^ ]+\\) \\$")
 314                    (setq locking-user (match-string-no-properties 1))
 315                    (setq status 'rev-and-lock))
 316                   ((looking-at " *\\$")
 317                    (setq locking-user 'none)
 318                    (setq status 'rev-and-lock))
 319                   (t
 320                    (setq locking-user 'none)
 321                    (setq status 'rev-and-lock)))
 322           (setq status 'rev)))
 323        ;; else: nothing found
 324        ;; -------------------
 325        (t nil)))
 326      (if status (vc-file-setprop file 'vc-workfile-version version))
 327      (and (eq status 'rev-and-lock)
 328           (vc-file-setprop file 'vc-state
 329                            (cond
 330                             ((eq locking-user 'none) 'up-to-date)
 331                             ((string= locking-user (vc-user-login-name)) 'edited)
 332                             (t locking-user)))
 333           ;; If the file has headers, we don't want to query the
 334           ;; master file, because that would eliminate all the
 335           ;; performance gain the headers brought us.  We therefore
 336           ;; use a heuristic now to find out whether locking is used
 337           ;; for this file.  If we trust the file permissions, and the
 338           ;; file is not locked, then if the file is read-only we
 339           ;; assume that locking is used for the file, otherwise
 340           ;; locking is not used.
 341           (not (vc-mistrust-permissions file))
 342           (vc-up-to-date-p file)
 343           (if (string-match ".r-..-..-." (nth 8 (file-attributes file)))
 344               (vc-file-setprop file 'vc-checkout-model 'locking)
 345             (vc-file-setprop file 'vc-checkout-model 'implicit)))
 346      status))))
 347
 348 (defun vc-rcs-workfile-unchanged-p (file)
 349   "RCS-specific implementation of vc-workfile-unchanged-p."
 350   ;; Try to use rcsdiff --brief.  If rcsdiff does not understand that,
 351   ;; do a double take and remember the fact for the future
 352   (let* ((version (concat "-r" (vc-workfile-version file)))
 353          (status (if (eq vc-rcsdiff-knows-brief 'no)
 354                      (vc-do-command nil 1 "rcsdiff" file version)
 355                    (vc-do-command nil 2 "rcsdiff" file "--brief" version))))
 356     (if (eq status 2)
 357         (if (not vc-rcsdiff-knows-brief)
 358             (setq vc-rcsdiff-knows-brief 'no
 359                   status (vc-do-command nil 1 "rcsdiff" file version))
 360           (error "rcsdiff failed"))
 361       (if (not vc-rcsdiff-knows-brief) (setq vc-rcsdiff-knows-brief 'yes)))
 362     ;; The workfile is unchanged if rcsdiff found no differences.
 363     (zerop status)))
 364
 365 (defun vc-rcs-trunk-p (rev)
 366   "Return t if REV is an RCS revision on the trunk."
 367   (not (eq nil (string-match "\\`[0-9]+\\.[0-9]+\\'" rev))))
 368
 369 (defun vc-rcs-branch-part (rev)
 370   "Return the branch part of an RCS revision number REV"
 371   (substring rev 0 (string-match "\\.[0-9]+\\'" rev)))
 372
 373 (defun vc-rcs-latest-on-branch-p (file &optional version)
 374   "Return non-nil if workfile version of FILE is the latest on its branch.
 375 When VERSION is given, perform check for that version."
 376   (unless version (setq version (vc-workfile-version file)))
 377   (with-temp-buffer
 378     (string= version
 379              (if (vc-rcs-trunk-p version)
 380                  (progn
 381                    ;; Compare VERSION to the head version number.
 382                    (vc-insert-file (vc-name file) "^[0-9]")
 383                    (vc-parse-buffer "^head[ \t\n]+\\([^;]+\\);" 1))
 384                ;; If we are not on the trunk, we need to examine the
 385                ;; whole current branch.
 386                (vc-insert-file (vc-name file) "^desc")
 387                (vc-rcs-find-most-recent-rev (vc-rcs-branch-part version))))))
 388 \f
 389 (defun vc-rcs-branch-p (rev)
 390   "Return t if REV is an RCS branch revision"
 391   (not (eq nil (string-match "\\`[0-9]+\\(\\.[0-9]+\\.[0-9]+\\)*\\'" rev))))
 392
 393 (defun vc-rcs-minor-part (rev)
 394   "Return the minor version number of an RCS revision number REV."
 395   (string-match "[0-9]+\\'" rev)
 396   (substring rev (match-beginning 0) (match-end 0)))
 397
 398 (defun vc-rcs-previous-version (rev)
 399   "Guess the previous RCS version number"
 400   (let ((branch (vc-rcs-branch-part rev))
 401         (minor-num (string-to-number (vc-rcs-minor-part rev))))
 402     (if (> minor-num 1)
 403         ;; version does probably not start a branch or release
 404         (concat branch "." (number-to-string (1- minor-num)))
 405       (if (vc-rcs-trunk-p rev)
 406           ;; we are at the beginning of the trunk --
 407           ;; don't know anything to return here
 408           ""
 409         ;; we are at the beginning of a branch --
 410         ;; return version of starting point
 411         (vc-rcs-branch-part branch)))))
 412
 413 (defun vc-rcs-print-log (file)
 414   "Get change log associated with FILE."
 415   (vc-do-command t 0 "rlog" (vc-name file)))
 416
 417 (defun vc-rcs-show-log-entry (version)
 418   (when (re-search-forward
 419          ;; also match some context, for safety
 420          (concat "----\nrevision " version
 421                  "\\(\tlocked by:.*\n\\|\n\\)date: ") nil t)
 422     ;; set the display window so that
 423     ;; the whole log entry is displayed
 424     (let (start end lines)
 425       (beginning-of-line) (forward-line -1) (setq start (point))
 426       (if (not (re-search-forward "^----*\nrevision" nil t))
 427           (setq end (point-max))
 428         (beginning-of-line) (forward-line -1) (setq end (point)))
 429       (setq lines (count-lines start end))
 430       (cond
 431        ;; if the global information and this log entry fit
 432        ;; into the window, display from the beginning
 433        ((< (count-lines (point-min) end) (window-height))
 434         (goto-char (point-min))
 435         (recenter 0)
 436         (goto-char start))
 437        ;; if the whole entry fits into the window,
 438        ;; display it centered
 439        ((< (1+ lines) (window-height))
 440         (goto-char start)
 441         (recenter (1- (- (/ (window-height) 2) (/ lines 2)))))
 442        ;; otherwise (the entry is too large for the window),
 443        ;; display from the start
 444        (t
 445         (goto-char start)
 446         (recenter 0))))))
 447
 448 (defun vc-rcs-assign-name (file name)
 449   "Assign to FILE's latest version a given NAME."
 450   (vc-do-command nil 0 "rcs" (vc-name file) (concat "-n" name ":")))
 451
 452 (defun vc-rcs-merge (file first-version &optional second-version)
 453   "Merge changes into current working copy of FILE.
 454 The changes are between FIRST-VERSION and SECOND-VERSION."
 455   (vc-do-command nil 1 "rcsmerge" (vc-name file)
 456                  "-kk"                  ; ignore keyword conflicts
 457                  (concat "-r" first-version)
 458                  (if second-version (concat "-r" second-version))))
 459
 460 (defun vc-rcs-check-headers ()
 461   "Check if the current file has any headers in it."
 462   (save-excursion
 463     (goto-char (point-min))
 464          (re-search-forward "\\$[A-Za-z\300-\326\330-\366\370-\377]+\
 465 \\(: [\t -#%-\176\240-\377]*\\)?\\$" nil t)))
 466
 467 (defun vc-rcs-clear-headers ()
 468   "Implementation of vc-clear-headers for RCS."
 469   (let ((case-fold-search nil))
 470     (goto-char (point-min))
 471     (while (re-search-forward
 472             (concat "\\$\\(Author\\|Date\\|Header\\|Id\\|Locker\\|Name\\|"
 473                     "RCSfile\\|Revision\\|Source\\|State\\): [^$\n]+\\$")
 474             nil t)
 475       (replace-match "$\\1$"))))
 476
 477 (defun vc-rcs-steal-lock (file &optional rev)
 478   "Steal the lock on the current workfile for FILE and revision REV.
 479 Needs RCS 5.6.2 or later for -M."
 480   (vc-do-command nil 0 "rcs" (vc-name file) "-M"
 481                  (concat "-u" rev) (concat "-l" rev)))
 482
 483 (defun vc-rcs-cancel-version (file writable)
 484   "Undo the most recent checkin of FILE.
 485 WRITABLE non-nil means previous version should be locked."
 486   (let* ((target (vc-workfile-version file))
 487          (previous (if (vc-trunk-p target) "" (vc-branch-part target)))
 488          (config (current-window-configuration))
 489          (done nil))
 490     (vc-do-command nil 0 "rcs" (vc-name file) (concat "-o" target))
 491     ;; Check out the most recent remaining version.  If it fails, because
 492     ;; the whole branch got deleted, do a double-take and check out the
 493     ;; version where the branch started.
 494     (while (not done)
 495       (condition-case err
 496           (progn
 497             (vc-do-command nil 0 "co" (vc-name file) "-f"
 498                            (concat (if writable "-l" "-u") previous))
 499             (setq done t))
 500         (error (set-buffer "*vc*")
 501                (goto-char (point-min))
 502                (if (search-forward "no side branches present for" nil t)
 503                    (progn (setq previous (vc-branch-part previous))
 504                           (vc-do-command nil 0 "rcs" (vc-name file)
 505                                          (concat "-b" previous))
 506                           ;; vc-do-command popped up a window with
 507                           ;; the error message.  Get rid of it, by
 508                           ;; restoring the old window configuration.
 509                           (set-window-configuration config))
 510                  ;; No, it was some other error: re-signal it.
 511                  (signal (car err) (cdr err))))))))
 512
 513 (defun vc-rcs-revert (file)
 514   "Revert FILE to the version it was based on."
 515   (vc-do-command nil 0 "co" (vc-name file) "-f"
 516                  (concat "-u" (vc-workfile-version file))))
 517
 518 (defun vc-rcs-rename-file (old new)
 519   ;; Just move the master file (using vc-rcs-master-templates).
 520   (vc-rename-master (vc-name old) new vc-rcs-master-templates))
 521
 522 (defun vc-release-greater-or-equal (r1 r2)
 523   "Compare release numbers, represented as strings.
 524 Release components are assumed cardinal numbers, not decimal fractions
 525 \(5.10 is a higher release than 5.9\).  Omitted fields are considered
 526 lower \(5.6.7 is earlier than 5.6.7.1\).  Comparison runs till the end
 527 of the string is found, or a non-numeric component shows up \(5.6.7 is
 528 earlier than \"5.6.7 beta\", which is probably not what you want in
 529 some cases\).  This code is suitable for existing RCS release numbers.
 530 CVS releases are handled reasonably, too \(1.3 < 1.4* < 1.5\)."
 531   (let (v1 v2 i1 i2)
 532     (catch 'done
 533       (or (and (string-match "^\\.?\\([0-9]+\\)" r1)
 534                (setq i1 (match-end 0))
 535                (setq v1 (string-to-number (match-string 1 r1)))
 536                (or (and (string-match "^\\.?\\([0-9]+\\)" r2)
 537                         (setq i2 (match-end 0))
 538                         (setq v2 (string-to-number (match-string 1 r2)))
 539                         (if (> v1 v2) (throw 'done t)
 540                           (if (< v1 v2) (throw 'done nil)
 541                             (throw 'done
 542                                    (vc-release-greater-or-equal
 543                                     (substring r1 i1)
 544                                     (substring r2 i2)))))))
 545                    (throw 'done t)))
 546           (or (and (string-match "^\\.?\\([0-9]+\\)" r2)
 547                    (throw 'done nil))
 548               (throw 'done t)))))
 549
 550 (defun vc-rcs-release-p (release)
 551   "Return t if we have RELEASE or better."
 552   (let ((installation (vc-rcs-system-release)))
 553     (if (and installation
 554              (not (eq installation 'unknown)))
 555         (vc-release-greater-or-equal installation release))))
 556
 557 (defun vc-rcs-checkin (file rev comment)
 558   "RCS-specific version of `vc-backend-checkin'."
 559   (let ((switches (if (stringp vc-checkin-switches)
 560                       (list vc-checkin-switches)
 561                     vc-checkin-switches)))
 562     (let ((old-version (vc-workfile-version file)) new-version)
 563       (apply 'vc-do-command nil 0 "ci" (vc-name file)
 564              ;; if available, use the secure check-in option
 565              (and (vc-rcs-release-p "5.6.4") "-j")
 566              (concat (if vc-keep-workfiles "-u" "-r") rev)
 567              (concat "-m" comment)
 568              switches)
 569       (vc-file-setprop file 'vc-workfile-version nil)
 570
 571       ;; determine the new workfile version
 572       (set-buffer "*vc*")
 573       (goto-char (point-min))
 574       (when (or (re-search-forward
 575                  "new revision: \\([0-9.]+\\);" nil t)
 576                 (re-search-forward
 577                  "reverting to previous revision \\([0-9.]+\\)" nil t))
 578         (setq new-version (match-string 1))
 579         (vc-file-setprop file 'vc-workfile-version new-version))
 580
 581       ;; if we got to a different branch, adjust the default
 582       ;; branch accordingly
 583       (cond
 584        ((and old-version new-version
 585              (not (string= (vc-rcs-branch-part old-version)
 586                            (vc-rcs-branch-part new-version))))
 587         (vc-do-command nil 0 "rcs" (vc-name file)
 588                        (if (vc-rcs-trunk-p new-version) "-b"
 589                          (concat "-b" (vc-rcs-branch-part new-version))))
 590         ;; If this is an old RCS release, we might have
 591         ;; to remove a remaining lock.
 592         (if (not (vc-rcs-release-p "5.6.2"))
 593             ;; exit status of 1 is also accepted.
 594             ;; It means that the lock was removed before.
 595             (vc-do-command nil 1 "rcs" (vc-name file)
 596                            (concat "-u" old-version))))))))
 597
 598 (defun vc-rcs-system-release ()
 599   "Return the RCS release installed on this system, as a string.
 600 Return symbol UNKNOWN if the release cannot be deducted.  The user can
 601 override this using variable `vc-rcs-release'.
 602
 603 If the user has not set variable `vc-rcs-release' and it is nil,
 604 variable `vc-rcs-release' is set to the returned value."
 605   (or vc-rcs-release
 606       (setq vc-rcs-release
 607             (or (and (zerop (vc-do-command nil nil "rcs" nil "-V"))
 608                      (with-current-buffer (get-buffer "*vc*")
 609                        (vc-parse-buffer "^RCS version \\([0-9.]+ *.*\\)" 1)))
 610                 'unknown))))
 611
 612 (defun vc-rcs-diff (file &optional oldvers newvers)
 613   "Get a difference report using RCS between two versions of FILE."
 614   (if (not oldvers) (setq oldvers (vc-workfile-version file)))
 615   ;; If we know that --brief is not supported, don't try it.
 616   (let* ((diff-switches-list (if (listp diff-switches)
 617                                  diff-switches
 618                                (list diff-switches)))
 619          (options (append (list "-q"
 620                                 (concat "-r" oldvers)
 621                                 (and newvers (concat "-r" newvers)))
 622                           diff-switches-list)))
 623     (apply 'vc-do-command t 1 "rcsdiff" file options)))
 624
 625 (defun vc-rcs-responsible-p (file)
 626   "Return non-nil if RCS thinks it would be responsible for registering FILE."
 627   ;; TODO: check for all the patterns in vc-rcs-master-templates
 628   (file-directory-p (expand-file-name "RCS" (file-name-directory file))))
 629
 630 (defun vc-rcs-register (file &optional rev comment)
 631   "Register FILE into the RCS version-control system.
 632 REV is the optional revision number for the file.  COMMENT can be used
 633 to provide an initial description of FILE.
 634
 635 `vc-register-switches' and `vc-rcs-register-switches' are passed to
 636 the RCS command (in that order).
 637
 638 Automatically retrieve a read-only version of the file with keywords
 639 expanded if `vc-keep-workfiles' is non-nil, otherwise, delete the workfile."
 640     (let ((subdir (expand-file-name "RCS" (file-name-directory file)))
 641           (switches (list
 642                      (if (stringp vc-register-switches)
 643                          (list vc-register-switches)
 644                        vc-register-switches)
 645                      (if (stringp vc-rcs-register-switches)
 646                      (list vc-rcs-register-switches)
 647                      vc-rcs-register-switches))))
 648
 649       (and (not (file-exists-p subdir))
 650            (not (directory-files (file-name-directory file)
 651                                  nil ".*,v$" t))
 652            (yes-or-no-p "Create RCS subdirectory? ")
 653            (make-directory subdir))
 654       (apply 'vc-do-command nil 0 "ci" file
 655              ;; if available, use the secure registering option
 656              (and (vc-rcs-release-p "5.6.4") "-i")
 657              (concat (if vc-keep-workfiles "-u" "-r") rev)
 658              (and comment (concat "-t-" comment))
 659              switches)
 660       ;; parse output to find master file name and workfile version
 661       (with-current-buffer "*vc*"
 662         (goto-char (point-min))
 663         (let ((name (if (looking-at (concat "^\\(.*\\)  <--  "
 664                                             (file-name-nondirectory file)))
 665                         (match-string 1))))
 666           (if (not name)
 667               ;; if we couldn't find the master name,
 668               ;; run vc-rcs-registered to get it
 669               ;; (will be stored into the vc-name property)
 670               (vc-rcs-registered file)
 671             (vc-file-setprop file 'vc-name
 672                              (if (file-name-absolute-p name)
 673                                  name
 674                                (expand-file-name
 675                                 name
 676                                 (file-name-directory file))))))
 677         (vc-file-setprop file 'vc-workfile-version
 678                          (if (re-search-forward
 679                               "^initial revision: \\([0-9.]+\\).*\n"
 680                               nil t)
 681                              (match-string 1))))))
 682
 683 (defun vc-rcs-checkout (file &optional writable rev workfile)
 684   "Retrieve a copy of a saved version of FILE into a workfile."
 685   (let ((filename (or workfile file))
 686         (file-buffer (get-file-buffer file))
 687         switches)
 688     (message "Checking out %s..." filename)
 689     (save-excursion
 690       ;; Change buffers to get local value of vc-checkout-switches.
 691       (if file-buffer (set-buffer file-buffer))
 692       (setq switches (if (stringp vc-checkout-switches)
 693                          (list vc-checkout-switches)
 694                        vc-checkout-switches))
 695       ;; Save this buffer's default-directory
 696       ;; and use save-excursion to make sure it is restored
 697       ;; in the same buffer it was saved in.
 698       (let ((default-directory default-directory))
 699         (save-excursion
 700           ;; Adjust the default-directory so that the check-out creates
 701           ;; the file in the right place.
 702           (setq default-directory (file-name-directory filename))
 703           (if workfile  ;; RCS
 704               ;; RCS can't check out into arbitrary file names directly.
 705               ;; Use `co -p' and make stdout point to the correct file.
 706               (let ((vc-modes (logior (file-modes (vc-name file))
 707                                       (if writable 128 0)))
 708                     (failed t))
 709                 (unwind-protect
 710                     (progn
 711                       (let ((coding-system-for-read 'no-conversion)
 712                             (coding-system-for-write 'no-conversion))
 713                         (with-temp-file filename
 714                           (apply 'vc-do-command
 715                                  (current-buffer) 0 "co" (vc-name file)
 716                                  "-q" ;; suppress diagnostic output
 717                                  (if writable "-l")
 718                                  (concat "-p" rev)
 719                                  switches)))
 720                       (set-file-modes filename
 721                                       (logior (file-modes (vc-name file))
 722                                               (if writable 128 0)))
 723                       (setq failed nil))
 724                   (and failed (file-exists-p filename)
 725                        (delete-file filename))))
 726             (let (new-version)
 727               ;; if we should go to the head of the trunk,
 728               ;; clear the default branch first
 729               (and rev (string= rev "")
 730                    (vc-do-command nil 0 "rcs" (vc-name file) "-b"))
 731               ;; now do the checkout
 732               (apply 'vc-do-command
 733                      nil 0 "co" (vc-name file)
 734                      ;; If locking is not strict, force to overwrite
 735                      ;; the writable workfile.
 736                      (if (eq (vc-checkout-model file) 'implicit) "-f")
 737                      (if writable "-l")
 738                      (if rev (concat "-r" rev)
 739                        ;; if no explicit revision was specified,
 740                        ;; check out that of the working file
 741                        (let ((workrev (vc-workfile-version file)))
 742                          (if workrev (concat "-r" workrev)
 743                            nil)))
 744                      switches)
 745               ;; determine the new workfile version
 746               (with-current-buffer "*vc*"
 747                 (setq new-version
 748                       (vc-parse-buffer "^revision \\([0-9.]+\\).*\n" 1)))
 749               (vc-file-setprop file 'vc-workfile-version new-version)
 750               ;; if necessary, adjust the default branch
 751               (and rev (not (string= rev ""))
 752                    (vc-do-command
 753                     nil 0 "rcs" (vc-name file)
 754                     (concat "-b"
 755                             (if (vc-rcs-latest-on-branch-p file new-version)
 756                                 (if (vc-rcs-trunk-p new-version) nil
 757                                   (vc-rcs-branch-part new-version))
 758                               new-version)))))))
 759         (message "Checking out %s...done" filename)))))
 760
 761 (provide 'vc-rcs)
 762
 763 ;;; vc-rcs.el ends here