| blob | d261692db04f97d99266ce6f0f4ac2c8f577b2cc |
1 ;;; vc.el --- drive a version-control system from within Emacs
3 ;; Copyright (C) 1992, 93, 94, 95, 96, 97 Free Software Foundation, Inc.
5 ;; Author: Eric S. Raymond <esr@snark.thyrsus.com>
6 ;; Maintainer: Andre Spiegel <spiegel@inf.fu-berlin.de>
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
13 ;; any later version.
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
25 ;;; Commentary:
27 ;; This mode is fully documented in the Emacs user's manual.
28 ;;
29 ;; This was designed and implemented by Eric Raymond <esr@snark.thyrsus.com>.
30 ;; Paul Eggert <eggert@twinsun.com>, Sebastian Kremer <sk@thp.uni-koeln.de>,
31 ;; and Richard Stallman contributed valuable criticism, support, and testing.
32 ;; CVS support was added by Per Cederqvist <ceder@lysator.liu.se>
33 ;; in Jan-Feb 1994. Further enhancements came from ttn.netcom.com and
34 ;; Andre Spiegel <spiegel@inf.fu-berlin.de>.
35 ;;
36 ;; Supported version-control systems presently include SCCS, RCS, and CVS.
37 ;;
38 ;; Some features will not work with old RCS versions. Where
39 ;; appropriate, VC finds out which version you have, and allows or
40 ;; disallows those features (stealing locks, for example, works only
41 ;; from 5.6.2 onwards).
42 ;; Even initial checkins will fail if your RCS version is so old that ci
43 ;; doesn't understand -t-; this has been known to happen to people running
44 ;; NExTSTEP 3.0.
45 ;;
46 ;; You can support the RCS -x option by adding pairs to the
47 ;; vc-master-templates list.
48 ;;
49 ;; Proper function of the SCCS diff commands requires the shellscript vcdiff
50 ;; to be installed somewhere on Emacs's path for executables.
51 ;;
52 ;; If your site uses the ChangeLog convention supported by Emacs, the
53 ;; function vc-comment-to-change-log should prove a useful checkin hook.
54 ;;
55 ;; This code depends on call-process passing back the subprocess exit
56 ;; status. Thus, you need Emacs 18.58 or later to run it. For the
57 ;; vc-directory command to work properly as documented, you need 19.
58 ;; You also need Emacs 19's ring.el.
59 ;;
60 ;; The vc code maintains some internal state in order to reduce expensive
61 ;; version-control operations to a minimum. Some names are only computed
62 ;; once. If you perform version control operations with RCS/SCCS/CVS while
63 ;; vc's back is turned, or move/rename master files while vc is running,
64 ;; vc may get seriously confused. Don't do these things!
65 ;;
66 ;; Developer's notes on some concurrency issues are included at the end of
67 ;; the file.
69 ;;; Code:
78 minor-mode-alist)))
80 ;; To implement support for a new version-control system, add another
81 ;; branch to the vc-backend-dispatch macro and fill it in in each
82 ;; call. The variable vc-master-templates in vc-hooks.el will also
83 ;; have to change.
86 "Execute FORM1, FORM2 or FORM3 for SCCS, RCS or CVS respectively.
87 If FORM3 is `RCS', use FORM2 for CVS as well as RCS.
88 \(CVS shares some code with RCS)."
95 )))
97 ;; General customization
100 "Version-control system in Emacs."
104 "*If non-nil, treat user as expert; suppress yes-no prompts on some things."
109 "*If non-nil, prompt for initial comment when a file is registered."
114 "*If non-nil, display run messages from back-end commands."
119 "*A string or list of strings specifying extra switches for checkin.
125 string))
129 "*A string or list of strings specifying extra switches for checkout.
135 string))
139 "*A string or list of strings; extra switches for registering a file.
145 string))
149 "*List of directory names to be ignored while recursively walking file trees."
156 ;;; This is duplicated in diff.el.
157 ;;; ...and customized.
161 ;;;###autoload
163 "*Normal hook (List of functions) run after a checkin is done.
164 See `run-hooks'."
168 ;;;###autoload
170 "*Normal hook (list of functions) run before a file gets checked in.
171 See `run-hooks'."
175 ;; Header-insertion hair
179 "*Header keywords to be inserted by `vc-insert-headers'.
180 Must be a list of two-element lists, the first element of each must
181 be `RCS', `CVS', or `SCCS'. The second element is the string to
182 be inserted for this particular backend."
194 "*Associate static header string templates with file types. A \%s in the
195 template is replaced with the first string associated with the file's
196 version-control type in `vc-header-alist'."
204 "*Special comment delimiters to be used in generating vc headers only.
205 Add an entry in this list if you need to override the normal comment-start
206 and comment-end variables. This will only be necessary if the mode language
207 is sensitive to blank lines."
214 ;; Default is to be extra careful for super-user.
216 "*Non-nil means be extra-careful in checkout.
217 Verify that the file really is not locked
218 and that its contents match what the master file says."
223 "*The release number of your RCS installation, as a string.
224 If nil, VC itself computes this value when it is first needed."
226 string)
230 "*The release number of your SCCS installation, as a string.
231 If nil, VC itself computes this value when it is first needed."
233 string)
237 "*The release number of your CVS installation, as a string.
238 If nil, VC itself computes this value when it is first needed."
240 string)
243 ;; Variables the user doesn't need to know about.
248 ;; In a log entry buffer, this is a local variable
249 ;; that points to the buffer for which it was made
250 ;; (either a file, or a VC dired buffer).
266 ;; Back-portability to Emacs 18
276 ; Conditionally rebind some things for Emacs 18 compatibility
282 ))
287 ;;; Find and compare backend releases
290 ;; Returns which backend release is installed on this system.
312 vc-sccs-release)))
315 ;; Compare release numbers, represented as strings.
316 ;; Release components are assumed cardinal numbers, not decimal
317 ;; fractions (5.10 is a higher release than 5.9). Omitted fields
318 ;; are considered lower (5.6.7 is earlier than 5.6.7.1).
319 ;; Comparison runs till the end of the string is found, or a
320 ;; non-numeric component shows up (5.6.7 is earlier than "5.6.7 beta",
321 ;; which is probably not what you want in some cases).
322 ;; This code is suitable for existing RCS release numbers.
323 ;; CVS releases are handled reasonably, too (1.3 < 1.4* < 1.5).
344 ;; Return t if we have RELEASE of BACKEND or better
351 ;;; functions that operate on RCS revision numbers
354 ;; return t if REV is a revision on the trunk
358 ;; return the branch part of a revision number REV
361 ;; File property caching
364 "Clear all cached file properties and the comment ring."
367 ;; Note: there is potential for minor lossage here if there is an open
368 ;; log buffer with a nonzero local value of vc-comment-ring-index.
372 ;; clear all properties of FILE that were retrieved
373 ;; from the master file
388 ;; Return the RCS head version of FILE
393 ;; Random helper functions
396 ;; return t iff the current workfile version of FILE is
397 ;; the latest on its branch.
399 ;; SCCS
401 ;; RCS
405 ;; Re-fetch the head version number. This is to make
406 ;; sure that no-one has checked in a new version behind
407 ;; our back.
410 workfile-version))
411 ;; If we are not on the trunk, we need to examine the
412 ;; whole current branch. (vc-master-workfile-version
413 ;; is not what we need.)
423 ;; CVS
424 t))
434 "Look for a command anywhere on the subprocess-command search path."
447 exec-path)
448 nil)))
451 "Execute a version-control command, notifying user and checking for errors.
452 Output from COMMAND goes to BUFFER, or *vc* if BUFFER is nil.
453 The command is successful if its exit status does not exceed OKSTATUS.
454 (If OKSTATUS is nil, that means to ignore errors.)
455 The last argument of the command is the master name of FILE if LAST is
456 `MASTER', or the workfile of FILE if LAST is `WORKFILE'; this is appended
457 to an optional list of FLAGS."
466 status)
477 flags)
488 ;; Add vc-path to PATH for the execution of this command.
491 path-separator
493 process-environment))
507 status))
508 )
511 )
513 status)
514 )
516 ;;; Save a bit of the text around POSN in the current buffer, to help
517 ;;; us find the corresponding position again later. This works even
518 ;;; if all markers are destroyed or corrupted.
519 ;;; A lot of this was shamelessly lifted from Sebastian Kremer's rcs.el mode.
526 ;;; Return the position of CONTEXT in the current buffer, or nil if we
527 ;;; couldn't find it.
537 ;; Can't use search-backward since the match may continue
538 ;; after point.
540 ;; goto-char doesn't signal an error at
541 ;; beginning of buffer like backward-char would
543 ;; to beginning of OSTRING
547 ;; Return a list '(point-context mark-context reparse); from which
548 ;; vc-restore-buffer-context can later restore the context.
550 ;; Use mark-marker to avoid confusion in transient-mark-mode.
553 ;; Make the right thing happen in transient-mark-mode.
555 ;; We may want to reparse the compilation buffer after revert
558 ;; Construct a list; each elt is nil or a buffer
559 ;; iff that buffer is a compilation output buffer
560 ;; that contains markers into the current buffer.
566 compilation-old-error-list
567 compilation-error-list))
582 ;; Restore point/mark, and reparse any affected compilation buffers.
583 ;; CONTEXT is that which vc-buffer-context returns.
587 ;; Reparse affected compilation buffers.
593 ;; Record the position in the compilation buffer of
594 ;; the last error next-error went to.
597 ;; Reparse the error messages as far as they were parsed before.
599 ;; Move the pointer up to find the error we were at before
600 ;; reparsing. Now next-error should properly go to the next one.
606 ;; Restore point and mark
614 ;; Revert buffer, try to keep point and mark where user expects them in spite
615 ;; of changes because of expanded version-control key words.
616 ;; This is quite important since otherwise typeahead won't work as expected.
620 ;; t means don't call normal-mode; that's to preserve various minor modes.
626 ;; Make sure the current buffer and its working file are in sync
627 ;; NOT-URGENT means it is ok to continue if the user says not to save.
633 nil
638 ;; Has the given workfile changed since last checkout?
645 ;; 0 stands for an unknown time; it can't match any mod time.
647 unchanged)))))
650 ;;; If comment is specified, it will be used as an admin or checkin comment.
653 owner version buffer)
656 ;; if there is no master file corresponding, create one
664 ;; CVS: changes to the master file need to be
665 ;; merged back into the working file
684 "Buffer %s modified; merge file on disc anyhow? "
688 ;; Overlaps detected - what now? Should use some
689 ;; fancy RCS conflict resolving package, or maybe
690 ;; emerge, but for now, simply warn the user with a
691 ;; message.
697 ;; If there is no lock on the file, assert one and get it.
698 ;; (With implicit checkout, make sure not to lose unsaved changes.)
709 file))
720 )
736 )))
738 ;; a checked-out version exists, but the user may not own the lock
747 file
750 owner))
752 ;; OK, user owns the lock on the file
758 ;; give luser a chance to save before checking in.
761 ;; Revert if file is unchanged and buffer is too.
762 ;; If buffer is modified, that means the user just said no
763 ;; to saving it; in that case, don't revert,
764 ;; because the user might intend to save
765 ;; after finishing the log entry.
768 ;; DO NOT revert the file without asking the user!
774 ;; user may want to set nonstandard parameters
778 ;; OK, let's do the checkin
780 )))))
783 ;; Do a vc-next-action-on-file on all the marked files, possibly
784 ;; passing on the log comment we've just entered.
792 ;; Adjust the default directory so that checkouts
793 ;; go to the right place.
801 nil t)))
803 ;; Here's the major entry point.
805 ;;;###autoload
807 "Do the next logical checkin or checkout operation on the current file.
808 If you call this from within a VC dired buffer with no files marked,
809 it will operate on the file in the current line.
810 If you call this from within a VC dired buffer, and one or more
811 files are marked, it will accept a log message and then operate on
812 each one. The log message will be used as a comment for any register
813 or checkin operations, but ignored when doing checkouts. Attempted
814 lock steals will raise an error.
815 A prefix argument lets you specify the version number to use.
817 For RCS and SCCS files:
818 If the file is not already registered, this registers it for version
819 control and then retrieves a writable, locked copy for editing.
820 If the file is registered and not locked by anyone, this checks out
821 a writable and locked file ready for editing.
822 If the file is checked out and locked by the calling user, this
823 first checks to see if the file has changed since checkout. If not,
824 it performs a revert.
825 If the file has been changed, this pops up a buffer for entry
826 of a log message; when the message has been entered, it checks in the
827 resulting changes along with the log message as change commentary. If
828 the variable `vc-keep-workfiles' is non-nil (which is its default), a
829 read-only copy of the changed file is left in place afterwards.
830 If the file is registered and locked by someone else, you are given
831 the option to steal the lock.
833 For CVS files:
834 If the file is not already registered, this registers it for version
836 If the file is added but not committed, it is committed.
837 If your working file is changed, but the repository file is
838 unchanged, this pops up a buffer for entry of a log message; when the
839 message has been entered, it checks in the resulting changes along
840 with the logmessage as change commentary. A writable file is retained.
841 If the repository file is changed, you are asked if you want to
842 merge in the changes into your working copy."
859 "Enter a change comment for the marked files."
868 ;;; These functions help the vc-next-action entry point
871 "Retrieve a writable copy of the latest version of the current buffer's file."
873 )
875 ;;;###autoload
877 "Register the current file into your version-control system."
887 ;; Watch out for new buffers of size 0: the corresponding file
888 ;; does not exist yet, even though buffer-modified-p is nil.
895 ;; inhibit backup for this buffer
899 buffer-file-name
903 )
906 ;; If the given file is in the current buffer,
907 ;; either revert on it so we see expanded keywords,
908 ;; or unvisit it (depending on vc-keep-workfiles)
909 ;; NOQUERY if non-nil inhibits confirmation for reverting.
910 ;; NOQUERY should be t *only* if it is known the only difference
911 ;; between the buffer and the file is due to RCS rather than user editing!
915 ;; temporarily remove vc-find-file-hook, so that
916 ;; we don't lose the properties
924 ;; if FILE is currently visited, resynch its buffer
932 ;; Accept a comment for an operation on FILE revision REV. If COMMENT
933 ;; is nil, pop up a VC-log buffer, emit MSG, and set the
934 ;; action on close to ACTION; otherwise, do action immediately.
935 ;; Remember the file's buffer in vc-parent-buffer (current one if no file).
936 ;; AFTER-HOOK specifies the local value for vc-log-operation-hook.
967 "Check a file into your version-control system.
968 FILE is the unmodified name of the file. REV should be the base version
969 level to check it in under. COMMENT, if specified, is the checkin comment."
973 nil))
976 "Retrieve a copy of the latest version of the given file."
977 ;; If ftp is on this system and the name matches the ange-ftp format
978 ;; for a remote file, the user is trying something that won't work.
985 "Steal the lock on the current workfile."
993 file-description owner)))
1009 ;; This is called when the notification has been sent.
1018 "Check in the file specified by FILE.
1019 The optional argument REV may be a string specifying the new version level
1020 \(if nil increment the current level). The file is either retained with write
1021 permissions zeroed, or deleted (according to the value of `vc-keep-workfiles').
1022 If the back-end is CVS, a writable workfile is always kept.
1023 COMMENT is a comment string; if omitted, a buffer is
1024 popped up to accept a comment."
1029 ;;; Here is a checkin hook that may prove useful to sites using the
1030 ;;; ChangeLog facility supported by Emacs.
1032 "Enter last VC comment into change log file for current buffer's file.
1033 Optional arg (interactive prefix) non-nil means prompt for user name and site.
1034 Second arg is file name of change log. \
1035 If nil, uses `change-log-default-name'."
1039 ;; Make sure the defvar for add-log-current-defun-function has been executed
1040 ;; before binding it.
1044 ;; Don't let add-change-log-entry insert a defun name.
1046 end)
1047 ;; Call add-log to do half the work.
1049 ;; Insert the VC comment, leaving point before it.
1052 ;; It starts with an open-paren, as in "(foo): Frobbed."
1053 ;; So remove the ": " add-log inserted.
1055 ;; Canonicalize the white space between the file name and comment.
1057 ;; Indent rest of the text the same way add-log indented the first line.
1064 ;; Fill the inserted text, preserving open-parens at bol.
1069 ;; Canonicalize the white space at the end of the entry so it is
1070 ;; separated from the next entry by a single blank line.
1078 "Complete the operation implied by the current log entry."
1080 ;; Check and record the comment, if any.
1086 ;; Comment too long?
1088 ;; Record the comment in the comment ring
1090 ))
1091 ;; Sync parent buffer in case the user modified it while editing the comment.
1092 ;; But not if it is a vc-dired buffer.
1098 ;; save the parameters held in buffer-local variables
1104 ;; Return to "parent" buffer of this checkin and remove checkin window
1109 ;; OK, do it to it
1112 log-file
1113 log-version
1114 log-entry))
1115 ;; Now make sure we see the expanded headers
1120 ;; Code for access to the comment ring
1123 "Cycle backwards through comment history."
1131 ;; Initialize the index on the first use of this command
1132 ;; so that the first M-p gets index 0, and the first M-n gets
1133 ;; index -1.
1144 "Cycle forwards through comment history."
1149 "Searches backwards through comment history for substring match."
1166 "Searches forwards through comment history for substring match."
1182 ;; Additional entry points for examining version histories
1184 ;;;###autoload
1186 "Display diffs between file versions.
1187 Normally this compares the current file and buffer with the most recent
1188 checked in version of that file. This uses no arguments.
1189 With a prefix argument, it reads the file name to use
1190 and two version designators specifying which versions to compare."
1202 unchanged)
1210 ;; Ideally, we'd like at this point to parse the diff so that
1211 ;; the buffer effectively goes into compilation mode and we
1212 ;; can visit the old and new change locations via next-error.
1213 ;; Unfortunately, this is just too painful to do. The basic
1214 ;; problem is that the `old' file doesn't exist to be
1215 ;; visited. This plays hell with numerous assumptions in
1216 ;; the diff.el and compile.el machinery.
1229 "For FILE, report diffs between two stored versions REL1 and REL2 of it.
1230 If FILE is a directory, generate diffs between versions for all registered
1231 files in or below it."
1244 " and "
1250 default-directory
1258 )))
1263 )
1268 ;;;###autoload
1270 "Visit version REV of the current buffer in another window.
1271 If the current buffer is named `F', the version is named `F.~REV~'.
1272 If `F.~REV~' already exists, it is used instead of being re-created."
1281 rev))
1288 ;; Header-insertion code
1290 ;;;###autoload
1292 "Insert headers in a file for use with your version-control system.
1293 Headers desired are inserted at the start of the buffer, and are pulled from
1294 the variable `vc-header-alist'."
1313 hdstrings)
1318 vc-static-header-alist))
1319 )
1320 )))))
1323 ;; Clear all version headers in the current buffer, i.e. reset them
1324 ;; to the nonexpanded form. Only implemented for RCS, yet.
1325 ;; Don't lose point and mark during this.
1332 ;; The VC directory major mode. Coopt Dired for this.
1333 ;; All VC commands get mapped into logical equivalents.
1336 "The major mode used in VC directory buffers. It is derived from Dired.
1337 All Dired commands operate normally. Users currently locking listed files
1338 are listed in place of the file's owner and group.
1339 Keystrokes bound to VC commands will execute as though they had been called
1340 on a buffer attached to the file named in the current Dired buffer line."
1348 ;; Return the string that indicates the version control status
1349 ;; on a VC dired line.
1362 ;; Hack a directory-listing line, plugging in locking-user info in
1363 ;; place of the user and group info. Should have the beneficial
1364 ;; side-effect of shortening the listing line. Each call starts with
1365 ;; point immediately following the dired mark area on the line to be
1366 ;; hacked.
1367 ;;
1368 ;; Simplest possible one:
1369 ;; (insert (concat x "\t")))
1370 ;;
1371 ;; This code, like dired, assumes UNIX -l format.
1380 limit t)
1383 limit t))
1389 limit t)
1397 ;; Update the vc-dired listing line of file -- it is assumed
1398 ;; that point is already on this line. Don't use dired-do-redisplay
1399 ;; for this, because it cannot handle the way vc-dired deals with
1400 ;; subdirectories.
1419 ;;; Note in Emacs 18 the following defun gets overridden
1420 ;;; with the symbol 'vc-directory-18. See below.
1421 ;;;###autoload
1423 "Show version-control status of the current directory and subdirectories.
1424 Normally it creates a Dired buffer that lists only the locked files
1425 in all these directories. With a prefix argument, it lists all files."
1429 ;; force a trailing slash
1436 dired-buf
1437 dired-buf-mod-count)
1439 dirname
1449 ;; This uses a semi-documented feature of dired; giving a switch
1450 ;; argument forces the buffer to refresh each time.
1457 ;; Make a few modifications to the header
1467 ;; Plug the version information into the individual lines
1478 )
1484 ))
1486 ;; Emacs 18 version
1488 "Show version-control status of all files under the current directory."
1496 default-directory
1513 )
1518 ;; Named-configuration support for SCCS
1523 vc-name-assoc-file
1531 ))
1537 vc-name-assoc-file
1542 ;; (replace-regexp (concat ":" (regexp-quote file) "$") (concat ":" newname))
1547 ))
1550 ;; Return the numeric version corresponding to a named snapshot of file
1551 ;; If name is nil or a version number string it's just passed through
1555 name)
1561 vc-name-assoc-file
1569 ))
1571 ;; Named-configuration entry points
1574 ;; Scan the tree below the current directory.
1575 ;; If any files are locked, return the name of the first such file.
1576 ;; (This means, neither snapshot creation nor retrieval is allowed.)
1577 ;; If one or more of the files are currently visited, return `visited'.
1578 ;; Otherwise, return nil.
1582 default-directory
1587 status)))
1589 ;;;###autoload
1591 "Make a snapshot called NAME.
1592 The snapshot is made from all registered files at or below the current
1593 directory. For each file, the version level of its latest
1594 version becomes part of the named configuration."
1600 default-directory
1604 )))
1606 ;;;###autoload
1608 "Retrieve the snapshot called NAME.
1609 This function fails if any files are locked at or below the current directory
1610 Otherwise, all registered files are checked out (unlocked) at their version
1611 levels in the snapshot."
1620 default-directory
1626 )))
1628 ;; Miscellaneous other entry points
1630 ;;;###autoload
1632 "List the change log of the current buffer in a window."
1651 ;; move point to the log entry for the current version
1654 ;; also match some context, for safety
1657 ;; set the display window so that
1658 ;; the whole log entry is displayed
1666 ;; if the global information and this log entry fit
1667 ;; into the window, display from the beginning
1672 ;; if the whole entry fits into the window,
1673 ;; display it centered
1677 ;; otherwise (the entry is too large for the window),
1678 ;; display from the start
1682 )
1684 )
1685 )
1687 ;;;###autoload
1689 "Revert the current buffer's file back to the latest checked-in version.
1690 This asks for confirmation if the buffer contents are not identical
1691 to that version.
1692 If the back-end is CVS, this will give you the most recent revision of
1693 the file on the branch you are editing."
1700 ;; This operation should always ask for confirmation.
1718 )
1719 )
1721 ;;;###autoload
1723 "Get rid of most recently checked in version of this file.
1724 A prefix argument means do not revert the buffer afterwards."
1743 nil
1747 ;; Check out the most recent remaining version. If it fails, because
1748 ;; the whole branch got deleted, do a double-take and check out the
1749 ;; version where the branch started.
1754 ;; Check out locked, but only to disc, and keep
1755 ;; modifications in the buffer.
1757 ;; Check out unlocked, and revert buffer.
1760 ;; If the checkout fails, vc-do-command signals an error.
1761 ;; We catch this error, check the reason, correct the
1762 ;; version number, and try a second time.
1767 ;; vc-do-command popped up a window with
1768 ;; the error message. Get rid of it, by
1769 ;; restoring the old window configuration.
1771 ;; No, it was some other error: re-signal it.
1773 ;; If norevert, clear version headers and mark the buffer modified.
1778 ;; inhibit backup for this buffer
1786 )))
1788 ;;;###autoload
1790 "Rename file OLD to NEW, and rename its master file likewise."
1792 ;; There are several ways of renaming files under CVS 1.3, but they all
1793 ;; have serious disadvantages. See the FAQ (available from think.com in
1794 ;; pub/cvs/). I'd rather send the user an error, than do something he might
1795 ;; consider to be wrong. When the famous, long-awaited rename database is
1796 ;; implemented things might change for the better. This is unlikely to occur
1797 ;; until CVS 2.0 is released. --ceder 1994-01-23 21:27:51
1813 ;; This had FILE, I changed it to OLD. -- rms.
1817 oldmaster
1831 vc-master-templates)
1835 ; ?? Renaming a file might change its contents due to keyword expansion.
1836 ; We should really check out a new copy if the old copy was precisely equal
1837 ; to some checked in version. However, testing for this is tricky....
1846 ;; This had FILE, I changed it to OLD. -- rms.
1849 nil ;RCS
1850 nil ;CVS
1851 )
1852 )
1854 ;;;###autoload
1856 "Find change log file and add entries from recent RCS/CVS logs.
1857 Normally, find log entries for all registered files in the default
1858 directory using `rcs2log', which finds CVS logs preferentially.
1859 The mark is left at the end of the text prepended to the change log.
1861 With prefix arg of C-u, only find log entries for the current buffer's file.
1863 With any numeric prefix arg, find log entries for all currently visited
1864 files that are under version control. This puts all the entries in the
1865 log for the default directory, which may not be appropriate.
1867 From a program, any arguments are assumed to be filenames and are
1868 passed to the `rcs2log' script after massaging to be relative to the
1869 default directory."
1876 file)
1882 files))
1884 ;; `rcs2log' will find the relevant RCS or CVS files
1885 ;; relative to the curent directory if none supplied.
1886 nil)))
1889 ;; Presumably not portable to non-Unixy systems, along with rcs2log:
1902 user-mail-address)))
1916 "-c" changelog
1925 f
1927 args)))
1928 "done"
1937 ;; Collect back-end-dependent stuff here
1940 ;; Register a file into the version-control system
1941 ;; Automatically retrieves a read-only version of the file with
1942 ;; keywords expanded if vc-keep-workfiles is non-nil, otherwise
1943 ;; it deletes the workfile.
1951 vc-register-switches))
1960 ;; If there is no SCCS subdirectory yet, create it.
1961 ;; (SCCS could do without it, but VC requires it to be there.)
1965 "-fb"
1972 switches)
1978 ;; if available, use the secure registering option
1982 switches))
1985 "add"
1988 switches)
1989 )))
1991 )
1994 ;; Retrieve a copy of a saved version into a workfile
1997 switches)
2000 ;; Change buffers to get local value of vc-checkout-switches.
2004 vc-checkout-switches))
2005 ;; Save this buffer's default-directory
2006 ;; and use save-excursion to make sure it is restored
2007 ;; in the same buffer it was saved in.
2010 ;; Adjust the default-directory so that the check-out creates
2011 ;; the file in the right place.
2017 ;; Some SCCS implementations allow checking out directly to a
2018 ;; file using the -G option, but then some don't so use the
2019 ;; least common denominator approach and use the -p option
2020 ;; ala RCS.
2028 ;; Some shells make the "" dummy argument into $0
2029 ;; while others use the shell's name as $0 and
2030 ;; use the "" as $1. The if-statement
2031 ;; converts the latter case to the former.
2038 filename
2040 "-p"
2043 switches)
2050 switches)
2053 ;; RCS doesn't let us check out into arbitrary file names directly.
2054 ;; Use `co -p' and make stdout point to the correct file.
2062 ;; See the SCCS case, above, regarding the
2063 ;; if-statement.
2070 filename
2073 switches)
2077 ;; if we should go to the head of the trunk,
2078 ;; clear the default branch first
2081 ;; now do the checkout
2084 ;; If locking is not strict, force to overwrite
2085 ;; the writable workfile.
2089 ;; if no explicit revision was specified,
2090 ;; check out that of the working file
2093 nil)))
2094 switches)
2095 ;; determine the new workfile version
2103 ;; if necessary, adjust the default branch
2109 new-version))))))
2111 ;; CVS is much like RCS
2119 workfile
2121 "-p"
2122 switches)
2125 ;; default for verbose checkout: clear the sticky tag
2126 ;; so that the actual update will get the head of the trunk
2129 ;; If a revision was specified, check that out.
2133 "update"
2136 switches)
2137 ;; If no revision was specified, simply make the file writable.
2159 nil ;; RCS
2161 )
2164 ;; Register changes to FILE as level REV with explanatory COMMENT.
2165 ;; Automatically retrieves a read-only version of the file with
2166 ;; keywords expanded if vc-keep-workfiles is non-nil, otherwise
2167 ;; it deletes the workfile.
2168 ;; Adaptation for RCS branch support: if this is an explicit checkin,
2169 ;; or if the checkin creates a new branch, set the master file branch
2170 ;; accordingly.
2172 ;; "This log message intentionally left almost blank".
2173 ;; RCS 5.7 gripes about white-space-only comments too.
2177 ;; Change buffers to get local value of vc-checkin-switches.
2182 vc-checkin-switches)))
2183 ;; Clear the master-properties. Do that here, not at the
2184 ;; end, because if the check-in fails we want them to get
2185 ;; re-computed before the next try.
2188 ;; SCCS
2193 switches)
2198 )
2199 ;; RCS
2202 ;; if available, use the secure check-in option
2206 switches)
2210 ;; determine the new workfile version
2221 ;; if we got to a different branch, adjust the default
2222 ;; branch accordingly
2230 ;; If this is an old RCS release, we might have
2231 ;; to remove a remaining lock.
2233 ;; exit status of 1 is also accepted.
2234 ;; It means that the lock was removed before.
2237 ;; CVS
2239 ;; explicit check-in to the trunk requires a
2240 ;; double check-in (first unexplicit) (CVS-1.3)
2246 switches))
2250 switches))
2252 ;; The CVS output will be on top of this message.
2255 ;; determine and store the new workfile version
2264 ;; if this was an explicit check-in, remove the sticky tag
2273 ;; Revert file to latest checked-in version.
2274 ;; (for RCS, to workfile version)
2278 file
2279 ;; SCCS
2283 ;; RCS
2286 ;; CVS
2293 )
2296 ;; Steal the lock on the current workfile. Needs RCS 5.6.2 or later for -M.
2302 )
2306 )
2309 )
2312 ;; Undo the latest checkin.
2317 nil ;; this is never reached under CVS
2318 )
2320 )
2323 ;; Get change log associated with FILE.
2325 file
2331 ;; Assign to a FILE's latest version a given NAME.
2336 )
2337 )
2340 ;; Get a difference report between two versions of FILE.
2341 ;; Get only a brief comparison report if CMP, a difference report otherwise.
2344 diff-switches
2357 ;; If we know that --brief is not supported, don't try it.
2365 ;; If --brief didn't work, do a double-take and remember it
2366 ;; for the future.
2372 ;; If --brief DID work, remember that, too.
2375 status))
2376 ;; CVS is different.
2379 ;; This file is added but not yet committed; there is no master file.
2383 ;; we regard this as "changed".
2384 ;; diff it against /dev/null.
2388 diff-switches
2390 ;; cmp is not yet implemented -- we always do a full diff.
2396 diff-switches
2402 ;; Merge in any new changes made to FILE.
2406 file
2414 ;; CVS doesn't return an error code if conflicts are detected.
2415 ;; Since we want to warn the user about it (and possibly start
2416 ;; emerge later), scan the output and see if this occurred.
2422 )))
2426 "Check if the current file has any headers in it."
2432 (re-search-forward "\\$[A-Za-z\300-\326\330-\366\370-\377]+\\(: [\t -#%-\176\240-\377]*\\)?\\$" nil t) ;; RCS
2434 )
2435 ))
2437 ;; Back-end-dependent stuff ends here.
2439 ;; Set up key bindings for use while editing log messages
2442 "Minor mode for driving version-control tools.
2443 These bindings are added to the global keymap when you enter this mode:
2456 While you are entering a change log message for a version, the following
2457 additional bindings will be in effect.
2461 Whenever you do a checkin, your log comment is added to a ring of
2462 saved comments. These can be recalled as follows:
2469 Entry to the change-log submode calls the value of text-mode-hook, then
2470 the value of vc-log-mode-hook.
2472 Global user options:
2473 vc-initial-comment If non-nil, require user to enter a change
2474 comment upon first checkin of the file.
2476 vc-keep-workfiles Non-nil value prevents workfiles from being
2477 deleted when changes are checked in
2479 vc-suppress-confirm Suppresses some confirmation prompts,
2480 notably for reversions.
2482 vc-header-alist Which keywords to insert when adding headers
2485 RCS and CVS.
2487 vc-static-header-alist By default, version headers inserted in C files
2488 get stuffed in a static string area so that
2489 ident(RCS/CVS) or what(SCCS) can see them in
2490 the compiled object code. You can override
2491 this by setting this variable to nil, or change
2492 the header template by changing it.
2494 vc-command-messages if non-nil, display run messages from the
2495 actual version-control utilities (this is
2496 intended primarily for people hacking vc
2497 itself).
2498 "
2512 )
2514 ;; Initialization code, to be done just once at load-time
2516 nil
2523 )
2525 ;;; These things should probably be generally available
2528 "Walk recursively through DIRNAME.
2529 Invoke FUNC f ARGS on each non-directory file f underneath it."
2552 ;;; DEVELOPER'S NOTES ON CONCURRENCY PROBLEMS IN THIS CODE
2553 ;;;
2554 ;;; These may be useful to anyone who has to debug or extend the package.
2555 ;;; (Note that this information corresponds to versions 5.x. Some of it
2556 ;;; might have been invalidated by the additions to support branching
2557 ;;; and RCS keyword lookup. AS, 1995/03/24)
2558 ;;;
2559 ;;; A fundamental problem in VC is that there are time windows between
2560 ;;; vc-next-action's computations of the file's version-control state and
2561 ;;; the actions that change it. This is a window open to lossage in a
2562 ;;; multi-user environment; someone else could nip in and change the state
2563 ;;; of the master during it.
2564 ;;;
2565 ;;; The performance problem is that rlog/prs calls are very expensive; we want
2566 ;;; to avoid them as much as possible.
2567 ;;;
2568 ;;; ANALYSIS:
2569 ;;;
2570 ;;; The performance problem, it turns out, simplifies in practice to the
2571 ;;; problem of making vc-locking-user fast. The two other functions that call
2572 ;;; prs/rlog will not be so commonly used that the slowdown is a problem; one
2573 ;;; makes snapshots, the other deletes the calling user's last change in the
2574 ;;; master.
2575 ;;;
2576 ;;; The race condition implies that we have to either (a) lock the master
2577 ;;; during the entire execution of vc-next-action, or (b) detect and
2578 ;;; recover from errors resulting from dispatch on an out-of-date state.
2579 ;;;
2580 ;;; Alternative (a) appears to be infeasible. The problem is that we can't
2581 ;;; guarantee that the lock will ever be removed. Suppose a user starts a
2582 ;;; checkin, the change message buffer pops up, and the user, having wandered
2583 ;;; off to do something else, simply forgets about it?
2584 ;;;
2585 ;;; Alternative (b), on the other hand, works well with a cheap way to speed up
2586 ;;; vc-locking-user. Usually, if a file is registered, we can read its locked/
2587 ;;; unlocked state and its current owner from its permissions.
2588 ;;;
2589 ;;; This shortcut will fail if someone has manually changed the workfile's
2590 ;;; permissions; also if developers are munging the workfile in several
2591 ;;; directories, with symlinks to a master (in this latter case, the
2592 ;;; permissions shortcut will fail to detect a lock asserted from another
2593 ;;; directory).
2594 ;;;
2595 ;;; Note that these cases correspond exactly to the errors which could happen
2596 ;;; because of a competing checkin/checkout race in between two instances of
2597 ;;; vc-next-action.
2598 ;;;
2599 ;;; For VC's purposes, a workfile/master pair may have the following states:
2600 ;;;
2601 ;;; A. Unregistered. There is a workfile, there is no master.
2602 ;;;
2603 ;;; B. Registered and not locked by anyone.
2604 ;;;
2605 ;;; C. Locked by calling user and unchanged.
2606 ;;;
2607 ;;; D. Locked by the calling user and changed.
2608 ;;;
2609 ;;; E. Locked by someone other than the calling user.
2610 ;;;
2611 ;;; This makes for 25 states and 20 error conditions. Here's the matrix:
2612 ;;;
2613 ;;; VC's idea of state
2614 ;;; |
2615 ;;; V Actual state RCS action SCCS action Effect
2616 ;;; A B C D E
2617 ;;; A . 1 2 3 4 ci -u -t- admin -fb -i<file> initial admin
2618 ;;; B 5 . 6 7 8 co -l get -e checkout
2619 ;;; C 9 10 . 11 12 co -u unget; get revert
2620 ;;; D 13 14 15 . 16 ci -u -m<comment> delta -y<comment>; get checkin
2621 ;;; E 17 18 19 20 . rcs -u -M -l unget -n ; get -g steal lock
2622 ;;;
2623 ;;; All commands take the master file name as a last argument (not shown).
2624 ;;;
2625 ;;; In the discussion below, a "self-race" is a pathological situation in
2626 ;;; which VC operations are being attempted simultaneously by two or more
2627 ;;; Emacsen running under the same username.
2628 ;;;
2629 ;;; The vc-next-action code has the following windows:
2630 ;;;
2631 ;;; Window P:
2632 ;;; Between the check for existence of a master file and the call to
2633 ;;; admin/checkin in vc-buffer-admin (apparent state A). This window may
2634 ;;; never close if the initial-comment feature is on.
2635 ;;;
2636 ;;; Window Q:
2637 ;;; Between the call to vc-workfile-unchanged-p in and the immediately
2638 ;;; following revert (apparent state C).
2639 ;;;
2640 ;;; Window R:
2641 ;;; Between the call to vc-workfile-unchanged-p in and the following
2642 ;;; checkin (apparent state D). This window may never close.
2643 ;;;
2644 ;;; Window S:
2645 ;;; Between the unlock and the immediately following checkout during a
2646 ;;; revert operation (apparent state C). Included in window Q.
2647 ;;;
2648 ;;; Window T:
2649 ;;; Between vc-locking-user and the following checkout (apparent state B).
2650 ;;;
2651 ;;; Window U:
2652 ;;; Between vc-locking-user and the following revert (apparent state C).
2653 ;;; Includes windows Q and S.
2654 ;;;
2655 ;;; Window V:
2656 ;;; Between vc-locking-user and the following checkin (apparent state
2657 ;;; D). This window may never be closed if the user fails to complete the
2658 ;;; checkin message. Includes window R.
2659 ;;;
2660 ;;; Window W:
2661 ;;; Between vc-locking-user and the following steal-lock (apparent
2662 ;;; state E). This window may never close if the user fails to complete
2663 ;;; the steal-lock message. Includes window X.
2664 ;;;
2665 ;;; Window X:
2666 ;;; Between the unlock and the immediately following re-lock during a
2667 ;;; steal-lock operation (apparent state E). This window may never cloce
2668 ;;; if the user fails to complete the steal-lock message.
2669 ;;;
2670 ;;; Errors:
2671 ;;;
2672 ;;; Apparent state A ---
2673 ;;;
2674 ;;; 1. File looked unregistered but is actually registered and not locked.
2675 ;;;
2676 ;;; Potential cause: someone else's admin during window P, with
2677 ;;; caller's admin happening before their checkout.
2678 ;;;
2679 ;;; RCS: Prior to version 5.6.4, ci fails with message
2680 ;;; "no lock set by <user>". From 5.6.4 onwards, VC uses the new
2681 ;;; ci -i option and the message is "<file>,v: already exists".
2682 ;;; SCCS: admin will fail with error (ad19).
2683 ;;;
2684 ;;; We can let these errors be passed up to the user.
2685 ;;;
2686 ;;; 2. File looked unregistered but is actually locked by caller, unchanged.
2687 ;;;
2688 ;;; Potential cause: self-race during window P.
2689 ;;;
2690 ;;; RCS: Prior to version 5.6.4, reverts the file to the last saved
2691 ;;; version and unlocks it. From 5.6.4 onwards, VC uses the new
2692 ;;; ci -i option, failing with message "<file>,v: already exists".
2693 ;;; SCCS: will fail with error (ad19).
2694 ;;;
2695 ;;; Either of these consequences is acceptable.
2696 ;;;
2697 ;;; 3. File looked unregistered but is actually locked by caller, changed.
2698 ;;;
2699 ;;; Potential cause: self-race during window P.
2700 ;;;
2701 ;;; RCS: Prior to version 5.6.4, VC registers the caller's workfile as
2702 ;;; a delta with a null change comment (the -t- switch will be
2703 ;;; ignored). From 5.6.4 onwards, VC uses the new ci -i option,
2704 ;;; failing with message "<file>,v: already exists".
2705 ;;; SCCS: will fail with error (ad19).
2706 ;;;
2707 ;;; 4. File looked unregistered but is locked by someone else.
2708 ;;;
2709 ;;; Potential cause: someone else's admin during window P, with
2710 ;;; caller's admin happening *after* their checkout.
2711 ;;;
2712 ;;; RCS: Prior to version 5.6.4, ci fails with a
2713 ;;; "no lock set by <user>" message. From 5.6.4 onwards,
2714 ;;; VC uses the new ci -i option, failing with message
2715 ;;; "<file>,v: already exists".
2716 ;;; SCCS: will fail with error (ad19).
2717 ;;;
2718 ;;; We can let these errors be passed up to the user.
2719 ;;;
2720 ;;; Apparent state B ---
2721 ;;;
2722 ;;; 5. File looked registered and not locked, but is actually unregistered.
2723 ;;;
2724 ;;; Potential cause: master file got nuked during window P.
2725 ;;;
2726 ;;; RCS: will fail with "RCS/<file>: No such file or directory"
2727 ;;; SCCS: will fail with error ut4.
2728 ;;;
2729 ;;; We can let these errors be passed up to the user.
2730 ;;;
2731 ;;; 6. File looked registered and not locked, but is actually locked by the
2732 ;;; calling user and unchanged.
2733 ;;;
2734 ;;; Potential cause: self-race during window T.
2735 ;;;
2736 ;;; RCS: in the same directory as the previous workfile, co -l will fail
2737 ;;; with "co error: writable foo exists; checkout aborted". In any other
2738 ;;; directory, checkout will succeed.
2739 ;;; SCCS: will fail with ge17.
2740 ;;;
2741 ;;; Either of these consequences is acceptable.
2742 ;;;
2743 ;;; 7. File looked registered and not locked, but is actually locked by the
2744 ;;; calling user and changed.
2745 ;;;
2746 ;;; As case 6.
2747 ;;;
2748 ;;; 8. File looked registered and not locked, but is actually locked by another
2749 ;;; user.
2750 ;;;
2751 ;;; Potential cause: someone else checks it out during window T.
2752 ;;;
2753 ;;; RCS: co error: revision 1.3 already locked by <user>
2754 ;;; SCCS: fails with ge4 (in directory) or ut7 (outside it).
2755 ;;;
2756 ;;; We can let these errors be passed up to the user.
2757 ;;;
2758 ;;; Apparent state C ---
2759 ;;;
2760 ;;; 9. File looks locked by calling user and unchanged, but is unregistered.
2761 ;;;
2762 ;;; As case 5.
2763 ;;;
2764 ;;; 10. File looks locked by calling user and unchanged, but is actually not
2765 ;;; locked.
2766 ;;;
2767 ;;; Potential cause: a self-race in window U, or by the revert's
2768 ;;; landing during window X of some other user's steal-lock or window S
2769 ;;; of another user's revert.
2770 ;;;
2771 ;;; RCS: succeeds, refreshing the file from the identical version in
2772 ;;; the master.
2773 ;;; SCCS: fails with error ut4 (p file nonexistent).
2774 ;;;
2775 ;;; Either of these consequences is acceptable.
2776 ;;;
2777 ;;; 11. File is locked by calling user. It looks unchanged, but is actually
2778 ;;; changed.
2779 ;;;
2780 ;;; Potential cause: the file would have to be touched by a self-race
2781 ;;; during window Q.
2782 ;;;
2783 ;;; The revert will succeed, removing whatever changes came with
2784 ;;; the touch. It is theoretically possible that work could be lost.
2785 ;;;
2786 ;;; 12. File looks like it's locked by the calling user and unchanged, but
2787 ;;; it's actually locked by someone else.
2788 ;;;
2789 ;;; Potential cause: a steal-lock in window V.
2790 ;;;
2791 ;;; RCS: co error: revision <rev> locked by <user>; use co -r or rcs -u
2792 ;;; SCCS: fails with error un2
2793 ;;;
2794 ;;; We can pass these errors up to the user.
2795 ;;;
2796 ;;; Apparent state D ---
2797 ;;;
2798 ;;; 13. File looks like it's locked by the calling user and changed, but it's
2799 ;;; actually unregistered.
2800 ;;;
2801 ;;; Potential cause: master file got nuked during window P.
2802 ;;;
2803 ;;; RCS: Prior to version 5.6.4, checks in the user's version as an
2804 ;;; initial delta. From 5.6.4 onwards, VC uses the new ci -j
2805 ;;; option, failing with message "no such file or directory".
2806 ;;; SCCS: will fail with error ut4.
2807 ;;;
2808 ;;; This case is kind of nasty. Under RCS prior to version 5.6.4,
2809 ;;; VC may fail to detect the loss of previous version information.
2810 ;;;
2811 ;;; 14. File looks like it's locked by the calling user and changed, but it's
2812 ;;; actually unlocked.
2813 ;;;
2814 ;;; Potential cause: self-race in window V, or the checkin happening
2815 ;;; during the window X of someone else's steal-lock or window S of
2816 ;;; someone else's revert.
2817 ;;;
2818 ;;; RCS: ci will fail with "no lock set by <user>".
2819 ;;; SCCS: delta will fail with error ut4.
2820 ;;;
2821 ;;; 15. File looks like it's locked by the calling user and changed, but it's
2822 ;;; actually locked by the calling user and unchanged.
2823 ;;;
2824 ;;; Potential cause: another self-race --- a whole checkin/checkout
2825 ;;; sequence by the calling user would have to land in window R.
2826 ;;;
2827 ;;; SCCS: checks in a redundant delta and leaves the file unlocked as usual.
2828 ;;; RCS: reverts to the file state as of the second user's checkin, leaving
2829 ;;; the file unlocked.
2830 ;;;
2831 ;;; It is theoretically possible that work could be lost under RCS.
2832 ;;;
2833 ;;; 16. File looks like it's locked by the calling user and changed, but it's
2834 ;;; actually locked by a different user.
2835 ;;;
2836 ;;; RCS: ci error: no lock set by <user>
2837 ;;; SCCS: unget will fail with error un2
2838 ;;;
2839 ;;; We can pass these errors up to the user.
2840 ;;;
2841 ;;; Apparent state E ---
2842 ;;;
2843 ;;; 17. File looks like it's locked by some other user, but it's actually
2844 ;;; unregistered.
2845 ;;;
2846 ;;; As case 13.
2847 ;;;
2848 ;;; 18. File looks like it's locked by some other user, but it's actually
2849 ;;; unlocked.
2850 ;;;
2851 ;;; Potential cause: someone released a lock during window W.
2852 ;;;
2853 ;;; RCS: The calling user will get the lock on the file.
2854 ;;; SCCS: unget -n will fail with cm4.
2855 ;;;
2856 ;;; Either of these consequences will be OK.
2857 ;;;
2858 ;;; 19. File looks like it's locked by some other user, but it's actually
2859 ;;; locked by the calling user and unchanged.
2860 ;;;
2861 ;;; Potential cause: the other user relinquishing a lock followed by
2862 ;;; a self-race, both in window W.
2863 ;;;
2864 ;;; Under both RCS and SCCS, both unlock and lock will succeed, making
2865 ;;; the sequence a no-op.
2866 ;;;
2867 ;;; 20. File looks like it's locked by some other user, but it's actually
2868 ;;; locked by the calling user and changed.
2869 ;;;
2870 ;;; As case 19.
2871 ;;;
2872 ;;; PROBLEM CASES:
2873 ;;;
2874 ;;; In order of decreasing severity:
2875 ;;;
2876 ;;; Cases 11 and 15 are the only ones that potentially lose work.
2877 ;;; They would require a self-race for this to happen.
2878 ;;;
2879 ;;; Case 13 in RCS loses information about previous deltas, retaining
2880 ;;; only the information in the current workfile. This can only happen
2881 ;;; if the master file gets nuked in window P.
2882 ;;;
2883 ;;; Case 3 in RCS and case 15 under SCCS insert a redundant delta with
2884 ;;; no change comment in the master. This would require a self-race in
2885 ;;; window P or R respectively.
2886 ;;;
2887 ;;; Cases 2, 10, 19 and 20 do extra work, but make no changes.
2888 ;;;
2889 ;;; Unfortunately, it appears to me that no recovery is possible in these
2890 ;;; cases. They don't yield error messages, so there's no way to tell that
2891 ;;; a race condition has occurred.
2892 ;;;
2893 ;;; All other cases don't change either the workfile or the master, and
2894 ;;; trigger command errors which the user will see.
2895 ;;;
2896 ;;; Thus, there is no explicit recovery code.
2898 ;;; vc.el ends here