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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.
179 Ages are given in units of 2**-16 seconds.
180 Default is eighteen steps using a twenty day increment."
185 "*Color for lines older than CAR of last cons in `vc-annotate-color-map'."
191 Default color is used if nil."
196 "*Menu elements for the mode-specific menu of VC-Annotate mode.
197 List of factors, used to expand/compress the time scale. See `vc-annotate'."
201 ;;;###autoload
203 "*Normal hook (List of functions) run after a checkin is done.
204 See `run-hooks'."
208 ;;;###autoload
210 "*Normal hook (list of functions) run before a file gets checked in.
211 See `run-hooks'."
215 ;;;###autoload
217 "*Hooks to run when VC-Annotate mode is turned on."
221 ;; Header-insertion hair
225 "*Header keywords to be inserted by `vc-insert-headers'.
226 Must be a list of two-element lists, the first element of each must
227 be `RCS', `CVS', or `SCCS'. The second element is the string to
228 be inserted for this particular backend."
240 "*Associate static header string templates with file types. A \%s in the
241 template is replaced with the first string associated with the file's
242 version-control type in `vc-header-alist'."
250 "*Special comment delimiters to be used in generating vc headers only.
251 Add an entry in this list if you need to override the normal comment-start
252 and comment-end variables. This will only be necessary if the mode language
253 is sensitive to blank lines."
260 ;; Default is to be extra careful for super-user.
262 "*Non-nil means be extra-careful in checkout.
263 Verify that the file really is not locked
264 and that its contents match what the master file says."
269 "*The release number of your RCS installation, as a string.
270 If nil, VC itself computes this value when it is first needed."
272 string)
276 "*The release number of your SCCS installation, as a string.
277 If nil, VC itself computes this value when it is first needed."
279 string)
283 "*The release number of your CVS installation, as a string.
284 If nil, VC itself computes this value when it is first needed."
286 string)
289 ;; Variables the user doesn't need to know about.
294 ;; In a log entry buffer, this is a local variable
295 ;; that points to the buffer for which it was made
296 ;; (either a file, or a VC dired buffer).
312 ;; Back-portability to Emacs 18
322 ; Conditionally rebind some things for Emacs 18 compatibility
328 ))
333 ;;; Find and compare backend releases
336 ;; Returns which backend release is installed on this system.
358 vc-sccs-release)))
361 ;; Compare release numbers, represented as strings.
362 ;; Release components are assumed cardinal numbers, not decimal
363 ;; fractions (5.10 is a higher release than 5.9). Omitted fields
364 ;; are considered lower (5.6.7 is earlier than 5.6.7.1).
365 ;; Comparison runs till the end of the string is found, or a
366 ;; non-numeric component shows up (5.6.7 is earlier than "5.6.7 beta",
367 ;; which is probably not what you want in some cases).
368 ;; This code is suitable for existing RCS release numbers.
369 ;; CVS releases are handled reasonably, too (1.3 < 1.4* < 1.5).
390 ;; Return t if we have RELEASE of BACKEND or better
397 ;;; functions that operate on RCS revision numbers
400 ;; return t if REV is a revision on the trunk
404 ;; return the branch part of a revision number REV
407 ;; File property caching
410 "Clear all cached file properties and the comment ring."
413 ;; Note: there is potential for minor lossage here if there is an open
414 ;; log buffer with a nonzero local value of vc-comment-ring-index.
418 ;; clear all properties of FILE that were retrieved
419 ;; from the master file
434 ;; Return the RCS head version of FILE
439 ;; Random helper functions
442 ;; return t iff the current workfile version of FILE is
443 ;; the latest on its branch.
445 ;; SCCS
447 ;; RCS
451 ;; Re-fetch the head version number. This is to make
452 ;; sure that no-one has checked in a new version behind
453 ;; our back.
456 workfile-version))
457 ;; If we are not on the trunk, we need to examine the
458 ;; whole current branch. (vc-master-workfile-version
459 ;; is not what we need.)
469 ;; CVS
470 t))
480 "Look for a command anywhere on the subprocess-command search path."
493 exec-path)
494 nil)))
497 "Execute a version-control command, notifying user and checking for errors.
498 Output from COMMAND goes to BUFFER, or *vc* if BUFFER is nil.
499 The command is successful if its exit status does not exceed OKSTATUS.
500 (If OKSTATUS is nil, that means to ignore errors.)
501 The last argument of the command is the master name of FILE if LAST is
502 `MASTER', or the workfile of FILE if LAST is `WORKFILE'; this is appended
503 to an optional list of FLAGS."
512 status)
523 flags)
534 ;; Add vc-path to PATH for the execution of this command.
537 path-separator
539 process-environment))
553 status))
554 )
557 )
559 status)
560 )
562 ;;; Save a bit of the text around POSN in the current buffer, to help
563 ;;; us find the corresponding position again later. This works even
564 ;;; if all markers are destroyed or corrupted.
565 ;;; A lot of this was shamelessly lifted from Sebastian Kremer's rcs.el mode.
572 ;;; Return the position of CONTEXT in the current buffer, or nil if we
573 ;;; couldn't find it.
583 ;; Can't use search-backward since the match may continue
584 ;; after point.
586 ;; goto-char doesn't signal an error at
587 ;; beginning of buffer like backward-char would
589 ;; to beginning of OSTRING
593 ;; Return a list '(point-context mark-context reparse); from which
594 ;; vc-restore-buffer-context can later restore the context.
596 ;; Use mark-marker to avoid confusion in transient-mark-mode.
599 ;; Make the right thing happen in transient-mark-mode.
601 ;; We may want to reparse the compilation buffer after revert
604 ;; Construct a list; each elt is nil or a buffer
605 ;; iff that buffer is a compilation output buffer
606 ;; that contains markers into the current buffer.
612 compilation-old-error-list
613 compilation-error-list))
628 ;; Restore point/mark, and reparse any affected compilation buffers.
629 ;; CONTEXT is that which vc-buffer-context returns.
633 ;; Reparse affected compilation buffers.
639 ;; Record the position in the compilation buffer of
640 ;; the last error next-error went to.
643 ;; Reparse the error messages as far as they were parsed before.
645 ;; Move the pointer up to find the error we were at before
646 ;; reparsing. Now next-error should properly go to the next one.
652 ;; Restore point and mark
660 ;; Revert buffer, try to keep point and mark where user expects them in spite
661 ;; of changes because of expanded version-control key words.
662 ;; This is quite important since otherwise typeahead won't work as expected.
666 ;; t means don't call normal-mode; that's to preserve various minor modes.
672 ;; Make sure the current buffer and its working file are in sync
673 ;; NOT-URGENT means it is ok to continue if the user says not to save.
679 nil
684 ;; Has the given workfile changed since last checkout?
691 ;; 0 stands for an unknown time; it can't match any mod time.
693 unchanged)))))
696 ;;; If comment is specified, it will be used as an admin or checkin comment.
699 owner version buffer)
702 ;; if there is no master file corresponding, create one
710 ;; CVS: changes to the master file need to be
711 ;; merged back into the working file
730 "Buffer %s modified; merge file on disc anyhow? "
734 ;; Overlaps detected - what now? Should use some
735 ;; fancy RCS conflict resolving package, or maybe
736 ;; emerge, but for now, simply warn the user with a
737 ;; message.
743 ;; If there is no lock on the file, assert one and get it.
744 ;; (With implicit checkout, make sure not to lose unsaved changes.)
755 file))
766 )
782 )))
784 ;; a checked-out version exists, but the user may not own the lock
793 file
796 owner))
798 ;; OK, user owns the lock on the file
804 ;; give luser a chance to save before checking in.
807 ;; Revert if file is unchanged and buffer is too.
808 ;; If buffer is modified, that means the user just said no
809 ;; to saving it; in that case, don't revert,
810 ;; because the user might intend to save
811 ;; after finishing the log entry.
814 ;; DO NOT revert the file without asking the user!
820 ;; user may want to set nonstandard parameters
824 ;; OK, let's do the checkin
826 )))))
829 ;; Do a vc-next-action-on-file on all the marked files, possibly
830 ;; passing on the log comment we've just entered.
838 ;; Adjust the default directory so that checkouts
839 ;; go to the right place.
847 nil t)))
849 ;; Here's the major entry point.
851 ;;;###autoload
853 "Do the next logical checkin or checkout operation on the current file.
854 If you call this from within a VC dired buffer with no files marked,
855 it will operate on the file in the current line.
856 If you call this from within a VC dired buffer, and one or more
857 files are marked, it will accept a log message and then operate on
858 each one. The log message will be used as a comment for any register
859 or checkin operations, but ignored when doing checkouts. Attempted
860 lock steals will raise an error.
861 A prefix argument lets you specify the version number to use.
863 For RCS and SCCS files:
864 If the file is not already registered, this registers it for version
865 control and then retrieves a writable, locked copy for editing.
866 If the file is registered and not locked by anyone, this checks out
867 a writable and locked file ready for editing.
868 If the file is checked out and locked by the calling user, this
869 first checks to see if the file has changed since checkout. If not,
870 it performs a revert.
871 If the file has been changed, this pops up a buffer for entry
872 of a log message; when the message has been entered, it checks in the
873 resulting changes along with the log message as change commentary. If
874 the variable `vc-keep-workfiles' is non-nil (which is its default), a
875 read-only copy of the changed file is left in place afterwards.
876 If the file is registered and locked by someone else, you are given
877 the option to steal the lock.
879 For CVS files:
880 If the file is not already registered, this registers it for version
882 If the file is added but not committed, it is committed.
883 If your working file is changed, but the repository file is
884 unchanged, this pops up a buffer for entry of a log message; when the
885 message has been entered, it checks in the resulting changes along
886 with the logmessage as change commentary. A writable file is retained.
887 If the repository file is changed, you are asked if you want to
888 merge in the changes into your working copy."
905 "Enter a change comment for the marked files."
914 ;;; These functions help the vc-next-action entry point
917 "Retrieve a writable copy of the latest version of the current buffer's file."
919 )
921 ;;;###autoload
923 "Register the current file into your version-control system."
933 ;; Watch out for new buffers of size 0: the corresponding file
934 ;; does not exist yet, even though buffer-modified-p is nil.
941 ;; inhibit backup for this buffer
945 buffer-file-name
949 )
952 ;; If the given file is in the current buffer,
953 ;; either revert on it so we see expanded keywords,
954 ;; or unvisit it (depending on vc-keep-workfiles)
955 ;; NOQUERY if non-nil inhibits confirmation for reverting.
956 ;; NOQUERY should be t *only* if it is known the only difference
957 ;; between the buffer and the file is due to RCS rather than user editing!
961 ;; temporarily remove vc-find-file-hook, so that
962 ;; we don't lose the properties
970 ;; if FILE is currently visited, resynch its buffer
978 ;; Accept a comment for an operation on FILE revision REV. If COMMENT
979 ;; is nil, pop up a VC-log buffer, emit MSG, and set the
980 ;; action on close to ACTION; otherwise, do action immediately.
981 ;; Remember the file's buffer in vc-parent-buffer (current one if no file).
982 ;; AFTER-HOOK specifies the local value for vc-log-operation-hook.
1013 "Check a file into your version-control system.
1014 FILE is the unmodified name of the file. REV should be the base version
1015 level to check it in under. COMMENT, if specified, is the checkin comment."
1019 nil))
1022 "Retrieve a copy of the latest version of the given file."
1023 ;; If ftp is on this system and the name matches the ange-ftp format
1024 ;; for a remote file, the user is trying something that won't work.
1031 "Steal the lock on the current workfile."
1039 file-description owner)))
1055 ;; This is called when the notification has been sent.
1064 "Check in the file specified by FILE.
1065 The optional argument REV may be a string specifying the new version level
1066 \(if nil increment the current level). The file is either retained with write
1067 permissions zeroed, or deleted (according to the value of `vc-keep-workfiles').
1068 If the back-end is CVS, a writable workfile is always kept.
1069 COMMENT is a comment string; if omitted, a buffer is
1070 popped up to accept a comment."
1075 ;;; Here is a checkin hook that may prove useful to sites using the
1076 ;;; ChangeLog facility supported by Emacs.
1078 "Enter last VC comment into change log file for current buffer's file.
1079 Optional arg (interactive prefix) non-nil means prompt for user name and site.
1080 Second arg is file name of change log. \
1081 If nil, uses `change-log-default-name'."
1085 ;; Make sure the defvar for add-log-current-defun-function has been executed
1086 ;; before binding it.
1090 ;; Don't let add-change-log-entry insert a defun name.
1092 end)
1093 ;; Call add-log to do half the work.
1095 ;; Insert the VC comment, leaving point before it.
1098 ;; It starts with an open-paren, as in "(foo): Frobbed."
1099 ;; So remove the ": " add-log inserted.
1101 ;; Canonicalize the white space between the file name and comment.
1103 ;; Indent rest of the text the same way add-log indented the first line.
1110 ;; Fill the inserted text, preserving open-parens at bol.
1115 ;; Canonicalize the white space at the end of the entry so it is
1116 ;; separated from the next entry by a single blank line.
1124 "Complete the operation implied by the current log entry."
1126 ;; Check and record the comment, if any.
1132 ;; Comment too long?
1134 ;; Record the comment in the comment ring
1136 ))
1137 ;; Sync parent buffer in case the user modified it while editing the comment.
1138 ;; But not if it is a vc-dired buffer.
1144 ;; save the parameters held in buffer-local variables
1150 ;; Return to "parent" buffer of this checkin and remove checkin window
1155 ;; OK, do it to it
1158 log-file
1159 log-version
1160 log-entry))
1161 ;; Now make sure we see the expanded headers
1166 ;; Code for access to the comment ring
1169 "Cycle backwards through comment history."
1177 ;; Initialize the index on the first use of this command
1178 ;; so that the first M-p gets index 0, and the first M-n gets
1179 ;; index -1.
1190 "Cycle forwards through comment history."
1195 "Searches backwards through comment history for substring match."
1212 "Searches forwards through comment history for substring match."
1228 ;; Additional entry points for examining version histories
1230 ;;;###autoload
1232 "Display diffs between file versions.
1233 Normally this compares the current file and buffer with the most recent
1234 checked in version of that file. This uses no arguments.
1235 With a prefix argument, it reads the file name to use
1236 and two version designators specifying which versions to compare."
1248 unchanged)
1256 ;; Ideally, we'd like at this point to parse the diff so that
1257 ;; the buffer effectively goes into compilation mode and we
1258 ;; can visit the old and new change locations via next-error.
1259 ;; Unfortunately, this is just too painful to do. The basic
1260 ;; problem is that the `old' file doesn't exist to be
1261 ;; visited. This plays hell with numerous assumptions in
1262 ;; the diff.el and compile.el machinery.
1275 "For FILE, report diffs between two stored versions REL1 and REL2 of it.
1276 If FILE is a directory, generate diffs between versions for all registered
1277 files in or below it."
1290 " and "
1296 default-directory
1304 )))
1309 )
1314 ;;;###autoload
1316 "Visit version REV of the current buffer in another window.
1317 If the current buffer is named `F', the version is named `F.~REV~'.
1318 If `F.~REV~' already exists, it is used instead of being re-created."
1327 rev))
1334 ;; Header-insertion code
1336 ;;;###autoload
1338 "Insert headers in a file for use with your version-control system.
1339 Headers desired are inserted at the start of the buffer, and are pulled from
1340 the variable `vc-header-alist'."
1359 hdstrings)
1364 vc-static-header-alist))
1365 )
1366 )))))
1369 ;; Clear all version headers in the current buffer, i.e. reset them
1370 ;; to the nonexpanded form. Only implemented for RCS, yet.
1371 ;; Don't lose point and mark during this.
1378 ;; The VC directory major mode. Coopt Dired for this.
1379 ;; All VC commands get mapped into logical equivalents.
1382 "The major mode used in VC directory buffers. It is derived from Dired.
1383 All Dired commands operate normally. Users currently locking listed files
1384 are listed in place of the file's owner and group.
1385 Keystrokes bound to VC commands will execute as though they had been called
1386 on a buffer attached to the file named in the current Dired buffer line."
1394 ;; Return the string that indicates the version control status
1395 ;; on a VC dired line.
1408 ;; Hack a directory-listing line, plugging in locking-user info in
1409 ;; place of the user and group info. Should have the beneficial
1410 ;; side-effect of shortening the listing line. Each call starts with
1411 ;; point immediately following the dired mark area on the line to be
1412 ;; hacked.
1413 ;;
1414 ;; Simplest possible one:
1415 ;; (insert (concat x "\t")))
1416 ;;
1417 ;; This code, like dired, assumes UNIX -l format.
1426 limit t)
1429 limit t))
1435 limit t)
1443 ;; Update the vc-dired listing line of file -- it is assumed
1444 ;; that point is already on this line. Don't use dired-do-redisplay
1445 ;; for this, because it cannot handle the way vc-dired deals with
1446 ;; subdirectories.
1465 ;;; Note in Emacs 18 the following defun gets overridden
1466 ;;; with the symbol 'vc-directory-18. See below.
1467 ;;;###autoload
1469 "Show version-control status of the current directory and subdirectories.
1470 Normally it creates a Dired buffer that lists only the locked files
1471 in all these directories. With a prefix argument, it lists all files."
1475 ;; force a trailing slash
1482 dired-buf
1483 dired-buf-mod-count)
1485 dirname
1495 ;; This uses a semi-documented feature of dired; giving a switch
1496 ;; argument forces the buffer to refresh each time.
1503 ;; Make a few modifications to the header
1513 ;; Plug the version information into the individual lines
1524 )
1530 ))
1532 ;; Emacs 18 version
1534 "Show version-control status of all files under the current directory."
1542 default-directory
1559 )
1564 ;; Named-configuration support for SCCS
1569 vc-name-assoc-file
1577 ))
1583 vc-name-assoc-file
1588 ;; (replace-regexp (concat ":" (regexp-quote file) "$") (concat ":" newname))
1593 ))
1596 ;; Return the numeric version corresponding to a named snapshot of file
1597 ;; If name is nil or a version number string it's just passed through
1601 name)
1607 vc-name-assoc-file
1615 ))
1617 ;; Named-configuration entry points
1620 ;; Scan the tree below the current directory.
1621 ;; If any files are locked, return the name of the first such file.
1622 ;; (This means, neither snapshot creation nor retrieval is allowed.)
1623 ;; If one or more of the files are currently visited, return `visited'.
1624 ;; Otherwise, return nil.
1628 default-directory
1633 status)))
1635 ;;;###autoload
1637 "Make a snapshot called NAME.
1638 The snapshot is made from all registered files at or below the current
1639 directory. For each file, the version level of its latest
1640 version becomes part of the named configuration."
1646 default-directory
1650 )))
1652 ;;;###autoload
1654 "Retrieve the snapshot called NAME.
1655 This function fails if any files are locked at or below the current directory
1656 Otherwise, all registered files are checked out (unlocked) at their version
1657 levels in the snapshot."
1666 default-directory
1672 )))
1674 ;; Miscellaneous other entry points
1676 ;;;###autoload
1678 "List the change log of the current buffer in a window."
1697 ;; move point to the log entry for the current version
1700 ;; also match some context, for safety
1703 ;; set the display window so that
1704 ;; the whole log entry is displayed
1712 ;; if the global information and this log entry fit
1713 ;; into the window, display from the beginning
1718 ;; if the whole entry fits into the window,
1719 ;; display it centered
1723 ;; otherwise (the entry is too large for the window),
1724 ;; display from the start
1728 )
1730 )
1731 )
1733 ;;;###autoload
1735 "Revert the current buffer's file back to the latest checked-in version.
1736 This asks for confirmation if the buffer contents are not identical
1737 to that version.
1738 If the back-end is CVS, this will give you the most recent revision of
1739 the file on the branch you are editing."
1746 ;; This operation should always ask for confirmation.
1764 )
1765 )
1767 ;;;###autoload
1769 "Get rid of most recently checked in version of this file.
1770 A prefix argument means do not revert the buffer afterwards."
1789 nil
1793 ;; Check out the most recent remaining version. If it fails, because
1794 ;; the whole branch got deleted, do a double-take and check out the
1795 ;; version where the branch started.
1800 ;; Check out locked, but only to disc, and keep
1801 ;; modifications in the buffer.
1803 ;; Check out unlocked, and revert buffer.
1806 ;; If the checkout fails, vc-do-command signals an error.
1807 ;; We catch this error, check the reason, correct the
1808 ;; version number, and try a second time.
1813 ;; vc-do-command popped up a window with
1814 ;; the error message. Get rid of it, by
1815 ;; restoring the old window configuration.
1817 ;; No, it was some other error: re-signal it.
1819 ;; If norevert, clear version headers and mark the buffer modified.
1824 ;; inhibit backup for this buffer
1832 )))
1834 ;;;###autoload
1836 "Rename file OLD to NEW, and rename its master file likewise."
1838 ;; There are several ways of renaming files under CVS 1.3, but they all
1839 ;; have serious disadvantages. See the FAQ (available from think.com in
1840 ;; pub/cvs/). I'd rather send the user an error, than do something he might
1841 ;; consider to be wrong. When the famous, long-awaited rename database is
1842 ;; implemented things might change for the better. This is unlikely to occur
1843 ;; until CVS 2.0 is released. --ceder 1994-01-23 21:27:51
1859 ;; This had FILE, I changed it to OLD. -- rms.
1863 oldmaster
1877 vc-master-templates)
1881 ; ?? Renaming a file might change its contents due to keyword expansion.
1882 ; We should really check out a new copy if the old copy was precisely equal
1883 ; to some checked in version. However, testing for this is tricky....
1892 ;; This had FILE, I changed it to OLD. -- rms.
1895 nil ;RCS
1896 nil ;CVS
1897 )
1898 )
1900 ;;;###autoload
1902 "Find change log file and add entries from recent RCS/CVS logs.
1903 Normally, find log entries for all registered files in the default
1904 directory using `rcs2log', which finds CVS logs preferentially.
1905 The mark is left at the end of the text prepended to the change log.
1907 With prefix arg of C-u, only find log entries for the current buffer's file.
1909 With any numeric prefix arg, find log entries for all currently visited
1910 files that are under version control. This puts all the entries in the
1911 log for the default directory, which may not be appropriate.
1913 From a program, any arguments are assumed to be filenames and are
1914 passed to the `rcs2log' script after massaging to be relative to the
1915 default directory."
1922 file)
1928 files))
1930 ;; `rcs2log' will find the relevant RCS or CVS files
1931 ;; relative to the curent directory if none supplied.
1932 nil)))
1935 ;; Presumably not portable to non-Unixy systems, along with rcs2log:
1948 user-mail-address)))
1962 "-c" changelog
1971 f
1973 args)))
1974 "done"
1982 \f
1983 ;; vc-annotate functionality (CVS only).
1993 ;; Syntax Table
1997 ;; Declare globally instead of additional parameter to
1998 ;; temp-buffer-show-function (not possible to pass more than one
1999 ;; parameter).
2015 "Major mode for buffers displaying output from the CVS `annotate' command.
2017 You can use the mode-specific menu to alter the time-span of the used
2018 colors. See variable `vc-annotate-menu-elements' for customizing the
2019 menu items."
2026 ; finds out what to describe.
2032 "Use the default color spectrum for VC Annotate mode."
2039 "Adds the menu 'Annotate' to the menu bar in VC-Annotate mode."
2041 '("Default" . vc-annotate-display-default))
2042 (let ((menu-elements vc-annotate-menu-elements))
2043 (while menu-elements
2044 (let* ((element (car menu-elements))
2045 (days (round (* element
2046 (vc-annotate-car-last-cons vc-annotate-color-map)
2047 0.7585))))
2048 (setq menu-elements (cdr menu-elements))
2049 (define-key vc-annotate-mode-menu
2050 (vector days)
2051 (cons (format "Span %d days"
2052 days)
2053 `(lambda ()
2054 ,(format "Use colors spanning %d days" days)
2055 (interactive)
2056 (message "Redisplaying annotation...")
2057 (vc-annotate-display
2058 (get-buffer (buffer-name))
2059 (vc-annotate-time-span vc-annotate-color-map ,element))
2060 (message "Redisplaying annotation...done"))))))))
2062 ;;;###autoload
2063 (defun vc-annotate (ratio)
2064 "Display the result of the CVS `annotate' command using colors.
2065 New lines are displayed in red, old in blue.
2066 A prefix argument specifies a factor for stretching the time scale.
2068 `vc-annotate-menu-elements' customizes the menu elements of the
2069 mode-specific menu. `vc-annotate-color-map' and
2070 `vc-annotate-very-old-color' defines the mapping of time to
2071 colors. `vc-annotate-background' specifies the background color."
2072 (interactive "p")
2073 (if (not (eq (vc-buffer-backend) 'CVS)) ; This only works with CVS
2074 (vc-registration-error (buffer-file-name)))
2075 (message "Annotating...")
2076 (let ((temp-buffer-name (concat "*cvs annotate " (buffer-name) "*"))
2077 (temp-buffer-show-function 'vc-annotate-display)
2078 (vc-annotate-ratio ratio))
2079 (with-output-to-temp-buffer temp-buffer-name
2080 (call-process "cvs" nil (get-buffer temp-buffer-name) nil
2081 "annotate" (file-name-nondirectory (buffer-file-name)))))
2082 (message "Annotating... done"))
2084 (defun vc-annotate-car-last-cons (assoc-list)
2085 "Return car of last cons in ASSOC-LIST."
2086 (if (not (eq nil (cdr assoc-list)))
2087 (vc-annotate-car-last-cons (cdr assoc-list))
2088 (car (car assoc-list))))
2090 ;; Return an association list with span factor applied to the
2091 ;; time-span of assoc-list. Optionaly quantize to the factor of
2092 ;; quantize.
2093 (defun vc-annotate-time-span (assoc-list span &optional quantize)
2094 ;; Apply span to each car of every cons
2095 (if (not (eq nil assoc-list))
2096 (append (list (cons (* (car (car assoc-list)) span)
2097 (cdr (car assoc-list))))
2098 (vc-annotate-time-span (nthcdr (cond (quantize) ; optional
2099 (1)) ; Default to cdr
2100 assoc-list) span quantize))))
2102 (defun vc-annotate-compcar (threshold &rest args)
2103 "Test successive cars of ARGS against THRESHOLD.
2104 Return the first cons which CAR is not less than THRESHOLD, nil otherwise"
2105 ;; If no list is exhausted,
2106 (if (and (not (memq 'nil args)) (< (car (car (car args))) threshold))
2107 ;; apply to CARs.
2108 (apply 'vc-annotate-compcar threshold
2109 ;; Recurse for rest of elements.
2110 (mapcar 'cdr args))
2111 ;; Return the proper result
2112 (car (car args))))
2114 (defun vc-annotate-display (buffer &optional color-map)
2115 "Do the VC-Annotate display in BUFFER using COLOR-MAP."
2117 ;; Handle the case of the global variable vc-annotate-ratio being
2118 ;; set. This variable is used to pass information from function
2119 ;; vc-annotate since it is not possible to use another parameter
2120 ;; (see temp-buffer-show-function).
2121 (if (and (not color-map) vc-annotate-ratio)
2122 ;; This will only be true if called from vc-annotate with ratio
2123 ;; being non-nil.
2124 (setq color-map (vc-annotate-time-span vc-annotate-color-map
2125 vc-annotate-ratio)))
2127 ;; We need a list of months and their corresponding numbers.
2128 (let* ((local-month-numbers
2129 '(("Jan" . 1) ("Feb" . 2) ("Mar" . 3) ("Apr" . 4)
2130 ("May" . 5) ("Jun" . 6) ("Jul" . 7) ("Aug" . 8)
2131 ("Sep" . 9) ("Oct" . 10) ("Nov" . 11) ("Dec" . 12)))
2132 ;; XEmacs use extents, GNU Emacs overlays.
2133 (overlay-or-extent (if (string-match "XEmacs" emacs-version)
2134 (cons 'make-extent 'set-extent-property)
2135 (cons 'make-overlay 'overlay-put)))
2136 (make-overlay-or-extent (car overlay-or-extent))
2137 (set-property-overlay-or-extent (cdr overlay-or-extent)))
2139 (set-buffer buffer)
2140 (display-buffer buffer)
2141 (if (not vc-annotate-mode) ; Turn on vc-annotate-mode if not done
2142 (vc-annotate-mode))
2143 (goto-char (point-min)) ; Position at the top of the buffer.
2144 (while (re-search-forward
2146 nil t)
2148 (let* (;; Unfortunately, order is important. match-string will
2149 ;; be corrupted by extent functions in XEmacs. Access
2150 ;; string-matches first.
2151 (day (string-to-number (match-string 2)))
2152 (month (cdr (assoc (match-string 3) local-month-numbers)))
2153 (year-tmp (string-to-number (match-string 4)))
2154 (year (+ (if (> 100 year-tmp) 1900 0) year-tmp)) ; Possible millenium problem
2155 (high (- (car (current-time))
2156 (car (encode-time 0 0 0 day month year))))
2157 (color (cond ((vc-annotate-compcar high (cond (color-map)
2158 (vc-annotate-color-map))))
2159 ((cons nil vc-annotate-very-old-color))))
2160 ;; substring from index 1 to remove any leading `#' in the name
2161 (face-name (concat "vc-annotate-face-" (substring (cdr color) 1)))
2162 ;; Make the face if not done.
2163 (face (cond ((intern-soft face-name))
2164 ((make-face (intern face-name)))))
2165 (point (point))
2166 (foo (forward-line 1))
2167 (overlay (cond ((if (string-match "XEmacs" emacs-version)
2168 (extent-at point)
2169 (car (overlays-at point ))))
2170 ((apply make-overlay-or-extent point (point) nil)))))
2172 (if vc-annotate-background
2173 (set-face-background face vc-annotate-background))
2174 (set-face-foreground face (cdr color))
2175 (apply set-property-overlay-or-extent overlay
2176 'face face nil)))))
2177 \f
2178 ;; Collect back-end-dependent stuff here
2180 (defun vc-backend-admin (file &optional rev comment)
2181 ;; Register a file into the version-control system
2182 ;; Automatically retrieves a read-only version of the file with
2183 ;; keywords expanded if vc-keep-workfiles is non-nil, otherwise
2184 ;; it deletes the workfile.
2185 (vc-file-clearprops file)
2186 (or vc-default-back-end
2187 (setq vc-default-back-end (if (vc-find-binary "rcs") 'RCS 'SCCS)))
2188 (message "Registering %s..." file)
2189 (let ((switches
2190 (if (stringp vc-register-switches)
2191 (list vc-register-switches)
2192 vc-register-switches))
2193 (backend
2194 (cond
2195 ((file-exists-p (vc-backend-subdirectory-name)) vc-default-back-end)
2196 ((file-exists-p "RCS") 'RCS)
2197 ((file-exists-p "SCCS") 'SCCS)
2198 ((file-exists-p "CVS") 'CVS)
2199 (t vc-default-back-end))))
2200 (cond ((eq backend 'SCCS)
2201 ;; If there is no SCCS subdirectory yet, create it.
2202 ;; (SCCS could do without it, but VC requires it to be there.)
2203 (if (not (file-exists-p "SCCS")) (make-directory "SCCS"))
2204 (apply 'vc-do-command nil 0 "admin" file 'MASTER ;; SCCS
2205 (and rev (concat "-r" rev))
2206 "-fb"
2207 (concat "-i" file)
2208 (and comment (concat "-y" comment))
2209 (format
2210 (car (rassq 'SCCS vc-master-templates))
2211 (or (file-name-directory file) "")
2212 (file-name-nondirectory file))
2213 switches)
2214 (delete-file file)
2215 (if vc-keep-workfiles
2216 (vc-do-command nil 0 "get" file 'MASTER)))
2217 ((eq backend 'RCS)
2218 (apply 'vc-do-command nil 0 "ci" file 'WORKFILE ;; RCS
2219 ;; if available, use the secure registering option
2220 (and (vc-backend-release-p 'RCS "5.6.4") "-i")
2221 (concat (if vc-keep-workfiles "-u" "-r") rev)
2222 (and comment (concat "-t-" comment))
2223 switches))
2224 ((eq backend 'CVS)
2225 (apply 'vc-do-command nil 0 "cvs" file 'WORKFILE ;; CVS
2226 "add"
2228 (concat "-m" comment))
2229 switches)
2230 )))
2231 (message "Registering %s...done" file)
2232 )
2234 (defun vc-backend-checkout (file &optional writable rev workfile)
2235 ;; Retrieve a copy of a saved version into a workfile
2236 (let ((filename (or workfile file))
2237 (file-buffer (get-file-buffer file))
2238 switches)
2239 (message "Checking out %s..." filename)
2240 (save-excursion
2241 ;; Change buffers to get local value of vc-checkout-switches.
2242 (if file-buffer (set-buffer file-buffer))
2243 (setq switches (if (stringp vc-checkout-switches)
2244 (list vc-checkout-switches)
2245 vc-checkout-switches))
2246 ;; Save this buffer's default-directory
2247 ;; and use save-excursion to make sure it is restored
2248 ;; in the same buffer it was saved in.
2249 (let ((default-directory default-directory))
2250 (save-excursion
2251 ;; Adjust the default-directory so that the check-out creates
2252 ;; the file in the right place.
2253 (setq default-directory (file-name-directory filename))
2254 (vc-backend-dispatch file
2255 (progn ;; SCCS
2256 (and rev (string= rev "") (setq rev nil))
2257 (if workfile
2258 ;; Some SCCS implementations allow checking out directly to a
2259 ;; file using the -G option, but then some don't so use the
2260 ;; least common denominator approach and use the -p option
2261 ;; ala RCS.
2262 (let ((vc-modes (logior (file-modes (vc-name file))
2263 (if writable 128 0)))
2264 (failed t))
2265 (unwind-protect
2266 (progn
2267 (apply 'vc-do-command
2268 nil 0 "/bin/sh" file 'MASTER "-c"
2269 ;; Some shells make the "" dummy argument into $0
2270 ;; while others use the shell's name as $0 and
2271 ;; use the "" as $1. The if-statement
2272 ;; converts the latter case to the former.
2276 (logand 511 (lognot vc-modes))
2277 (logand 511 (lognot (default-file-modes))))
2278 "" ; dummy argument for shell's $0
2279 filename
2280 (if writable "-e")
2281 "-p"
2282 (and rev
2283 (concat "-r" (vc-lookup-triple file rev)))
2284 switches)
2285 (setq failed nil))
2286 (and failed (file-exists-p filename)
2287 (delete-file filename))))
2288 (apply 'vc-do-command nil 0 "get" file 'MASTER ;; SCCS
2289 (if writable "-e")
2290 (and rev (concat "-r" (vc-lookup-triple file rev)))
2291 switches)
2292 (vc-file-setprop file 'vc-workfile-version nil)))
2293 (if workfile ;; RCS
2294 ;; RCS doesn't let us check out into arbitrary file names directly.
2295 ;; Use `co -p' and make stdout point to the correct file.
2296 (let ((vc-modes (logior (file-modes (vc-name file))
2297 (if writable 128 0)))
2298 (failed t))
2299 (unwind-protect
2300 (progn
2301 (apply 'vc-do-command
2302 nil 0 "/bin/sh" file 'MASTER "-c"
2303 ;; See the SCCS case, above, regarding the
2304 ;; if-statement.
2308 (logand 511 (lognot vc-modes))
2309 (logand 511 (lognot (default-file-modes))))
2310 "" ; dummy argument for shell's $0
2311 filename
2312 (if writable "-l")
2313 (concat "-p" rev)
2314 switches)
2315 (setq failed nil))
2316 (and failed (file-exists-p filename) (delete-file filename))))
2317 (let (new-version)
2318 ;; if we should go to the head of the trunk,
2319 ;; clear the default branch first
2320 (and rev (string= rev "")
2321 (vc-do-command nil 0 "rcs" file 'MASTER "-b"))
2322 ;; now do the checkout
2323 (apply 'vc-do-command
2324 nil 0 "co" file 'MASTER
2325 ;; If locking is not strict, force to overwrite
2326 ;; the writable workfile.
2327 (if (eq (vc-checkout-model file) 'implicit) "-f")
2328 (if writable "-l")
2329 (if rev (concat "-r" rev)
2330 ;; if no explicit revision was specified,
2331 ;; check out that of the working file
2332 (let ((workrev (vc-workfile-version file)))
2333 (if workrev (concat "-r" workrev)
2334 nil)))
2335 switches)
2336 ;; determine the new workfile version
2337 (save-excursion
2338 (set-buffer "*vc*")
2339 (goto-char (point-min))
2340 (setq new-version
2342 (buffer-substring (match-beginning 1) (match-end 1)))))
2343 (vc-file-setprop file 'vc-workfile-version new-version)
2344 ;; if necessary, adjust the default branch
2345 (and rev (not (string= rev ""))
2346 (vc-do-command nil 0 "rcs" file 'MASTER
2347 (concat "-b" (if (vc-latest-on-branch-p file)
2348 (if (vc-trunk-p new-version) nil
2349 (vc-branch-part new-version))
2350 new-version))))))
2351 (if workfile ;; CVS
2352 ;; CVS is much like RCS
2353 (let ((failed t))
2354 (unwind-protect
2355 (progn
2356 (apply 'vc-do-command
2357 nil 0 "/bin/sh" file 'WORKFILE "-c"
2359 "" ; dummy argument for shell's $0
2360 workfile
2361 (concat "-r" rev)
2362 "-p"
2363 switches)
2364 (setq failed nil))
2365 (and failed (file-exists-p filename) (delete-file filename))))
2366 ;; default for verbose checkout: clear the sticky tag
2367 ;; so that the actual update will get the head of the trunk
2368 (and rev (string= rev "")
2369 (vc-do-command nil 0 "cvs" file 'WORKFILE "update" "-A"))
2370 ;; If a revision was specified, check that out.
2371 (if rev
2372 (apply 'vc-do-command nil 0 "cvs" file 'WORKFILE
2373 (and writable (eq (vc-checkout-model file) 'manual) "-w")
2374 "update"
2375 (and rev (not (string= rev ""))
2376 (concat "-r" rev))
2377 switches)
2378 ;; If no revision was specified, simply make the file writable.
2379 (and writable
2380 (or (eq (vc-checkout-model file) 'manual)
2381 (zerop (logand 128 (file-modes file))))
2382 (set-file-modes file (logior 128 (file-modes file)))))
2383 (if rev (vc-file-setprop file 'vc-workfile-version nil))))
2384 (cond
2385 ((not workfile)
2386 (vc-file-clear-masterprops file)
2387 (if writable
2388 (vc-file-setprop file 'vc-locking-user (vc-user-login-name)))
2389 (vc-file-setprop file
2390 'vc-checkout-time (nth 5 (file-attributes file)))))
2391 (message "Checking out %s...done" filename))))))
2393 (defun vc-backend-logentry-check (file)
2394 (vc-backend-dispatch file
2395 (if (>= (buffer-size) 512) ;; SCCS
2396 (progn
2397 (goto-char 512)
2398 (error
2399 "Log must be less than 512 characters; point is now at pos 512")))
2400 nil ;; RCS
2401 nil) ;; CVS
2402 )
2404 (defun vc-backend-checkin (file rev comment)
2405 ;; Register changes to FILE as level REV with explanatory COMMENT.
2406 ;; Automatically retrieves a read-only version of the file with
2407 ;; keywords expanded if vc-keep-workfiles is non-nil, otherwise
2408 ;; it deletes the workfile.
2409 ;; Adaptation for RCS branch support: if this is an explicit checkin,
2410 ;; or if the checkin creates a new branch, set the master file branch
2411 ;; accordingly.
2412 (message "Checking in %s..." file)
2413 ;; "This log message intentionally left almost blank".
2414 ;; RCS 5.7 gripes about white-space-only comments too.
2416 (setq comment "*** empty log message ***"))
2417 (save-excursion
2418 ;; Change buffers to get local value of vc-checkin-switches.
2419 (set-buffer (or (get-file-buffer file) (current-buffer)))
2420 (let ((switches
2421 (if (stringp vc-checkin-switches)
2422 (list vc-checkin-switches)
2423 vc-checkin-switches)))
2424 ;; Clear the master-properties. Do that here, not at the
2425 ;; end, because if the check-in fails we want them to get
2426 ;; re-computed before the next try.
2427 (vc-file-clear-masterprops file)
2428 (vc-backend-dispatch file
2429 ;; SCCS
2430 (progn
2431 (apply 'vc-do-command nil 0 "delta" file 'MASTER
2432 (if rev (concat "-r" rev))
2433 (concat "-y" comment)
2434 switches)
2435 (vc-file-setprop file 'vc-locking-user 'none)
2436 (vc-file-setprop file 'vc-workfile-version nil)
2437 (if vc-keep-workfiles
2438 (vc-do-command nil 0 "get" file 'MASTER))
2439 )
2440 ;; RCS
2441 (let ((old-version (vc-workfile-version file)) new-version)
2442 (apply 'vc-do-command nil 0 "ci" file 'MASTER
2443 ;; if available, use the secure check-in option
2444 (and (vc-backend-release-p 'RCS "5.6.4") "-j")
2445 (concat (if vc-keep-workfiles "-u" "-r") rev)
2446 (concat "-m" comment)
2447 switches)
2448 (vc-file-setprop file 'vc-locking-user 'none)
2449 (vc-file-setprop file 'vc-workfile-version nil)
2451 ;; determine the new workfile version
2452 (set-buffer "*vc*")
2453 (goto-char (point-min))
2454 (if (or (re-search-forward
2456 (re-search-forward
2458 (progn (setq new-version (buffer-substring (match-beginning 1)
2459 (match-end 1)))
2460 (vc-file-setprop file 'vc-workfile-version new-version)))
2462 ;; if we got to a different branch, adjust the default
2463 ;; branch accordingly
2464 (cond
2465 ((and old-version new-version
2466 (not (string= (vc-branch-part old-version)
2467 (vc-branch-part new-version))))
2468 (vc-do-command nil 0 "rcs" file 'MASTER
2469 (if (vc-trunk-p new-version) "-b"
2470 (concat "-b" (vc-branch-part new-version))))
2471 ;; If this is an old RCS release, we might have
2472 ;; to remove a remaining lock.
2473 (if (not (vc-backend-release-p 'RCS "5.6.2"))
2474 ;; exit status of 1 is also accepted.
2475 ;; It means that the lock was removed before.
2476 (vc-do-command nil 1 "rcs" file 'MASTER
2477 (concat "-u" old-version))))))
2478 ;; CVS
2479 (progn
2480 ;; explicit check-in to the trunk requires a
2481 ;; double check-in (first unexplicit) (CVS-1.3)
2482 (condition-case nil
2483 (progn
2484 (if (and rev (vc-trunk-p rev))
2485 (apply 'vc-do-command nil 0 "cvs" file 'WORKFILE
2486 "ci" "-m" "intermediate"
2487 switches))
2488 (apply 'vc-do-command nil 0 "cvs" file 'WORKFILE
2489 "ci" (if rev (concat "-r" rev))
2490 (concat "-m" comment)
2491 switches))
2492 (error (if (eq (vc-cvs-status file) 'needs-merge)
2493 ;; The CVS output will be on top of this message.
2494 (error "Type C-x 0 C-x C-q to merge in changes")
2495 (error "Check-in failed"))))
2496 ;; determine and store the new workfile version
2497 (set-buffer "*vc*")
2498 (goto-char (point-min))
2499 (if (re-search-forward
2501 (vc-file-setprop file 'vc-workfile-version
2502 (buffer-substring (match-beginning 2)
2503 (match-end 2)))
2504 (vc-file-setprop file 'vc-workfile-version nil))
2505 ;; if this was an explicit check-in, remove the sticky tag
2506 (if rev
2507 (vc-do-command nil 0 "cvs" file 'WORKFILE "update" "-A"))
2508 (vc-file-setprop file 'vc-locking-user 'none)
2509 (vc-file-setprop file 'vc-checkout-time
2510 (nth 5 (file-attributes file)))))))
2511 (message "Checking in %s...done" file))
2513 (defun vc-backend-revert (file)
2514 ;; Revert file to latest checked-in version.
2515 ;; (for RCS, to workfile version)
2516 (message "Reverting %s..." file)
2517 (vc-file-clear-masterprops file)
2518 (vc-backend-dispatch
2519 file
2520 ;; SCCS
2521 (progn
2522 (vc-do-command nil 0 "unget" file 'MASTER nil)
2523 (vc-do-command nil 0 "get" file 'MASTER nil))
2524 ;; RCS
2525 (vc-do-command nil 0 "co" file 'MASTER
2526 "-f" (concat "-u" (vc-workfile-version file)))
2527 ;; CVS
2528 (progn
2529 (delete-file file)
2530 (vc-do-command nil 0 "cvs" file 'WORKFILE "update")))
2531 (vc-file-setprop file 'vc-locking-user 'none)
2532 (vc-file-setprop file 'vc-checkout-time (nth 5 (file-attributes file)))
2533 (message "Reverting %s...done" file)
2534 )
2536 (defun vc-backend-steal (file &optional rev)
2537 ;; Steal the lock on the current workfile. Needs RCS 5.6.2 or later for -M.
2538 (message "Stealing lock on %s..." file)
2539 (vc-backend-dispatch file
2540 (progn ;SCCS
2541 (vc-do-command nil 0 "unget" file 'MASTER "-n" (if rev (concat "-r" rev)))
2542 (vc-do-command nil 0 "get" file 'MASTER "-g" (if rev (concat "-r" rev)))
2543 )
2544 (vc-do-command nil 0 "rcs" file 'MASTER ;RCS
2545 "-M" (concat "-u" rev) (concat "-l" rev))
2546 (error "You cannot steal a CVS lock; there are no CVS locks to steal") ;CVS
2547 )
2548 (vc-file-setprop file 'vc-locking-user (vc-user-login-name))
2549 (message "Stealing lock on %s...done" file)
2550 )
2552 (defun vc-backend-uncheck (file target)
2553 ;; Undo the latest checkin.
2554 (message "Removing last change from %s..." file)
2555 (vc-backend-dispatch file
2556 (vc-do-command nil 0 "rmdel" file 'MASTER (concat "-r" target))
2557 (vc-do-command nil 0 "rcs" file 'MASTER (concat "-o" target))
2558 nil ;; this is never reached under CVS
2559 )
2560 (message "Removing last change from %s...done" file)
2561 )
2563 (defun vc-backend-print-log (file)
2564 ;; Get change log associated with FILE.
2565 (vc-backend-dispatch
2566 file
2567 (vc-do-command nil 0 "prs" file 'MASTER)
2568 (vc-do-command nil 0 "rlog" file 'MASTER)
2569 (vc-do-command nil 0 "cvs" file 'WORKFILE "log")))
2571 (defun vc-backend-assign-name (file name)
2572 ;; Assign to a FILE's latest version a given NAME.
2573 (vc-backend-dispatch file
2574 (vc-add-triple name file (vc-latest-version file)) ;; SCCS
2575 (vc-do-command nil 0 "rcs" file 'MASTER (concat "-n" name ":")) ;; RCS
2576 (vc-do-command nil 0 "cvs" file 'WORKFILE "tag" name) ;; CVS
2577 )
2578 )
2580 (defun vc-backend-diff (file &optional oldvers newvers cmp)
2581 ;; Get a difference report between two versions of FILE.
2582 ;; Get only a brief comparison report if CMP, a difference report otherwise.
2583 (let ((backend (vc-backend file)) options status
2584 (diff-switches-list (if (listp diff-switches)
2585 diff-switches
2586 (list diff-switches))))
2587 (cond
2588 ((eq backend 'SCCS)
2589 (setq oldvers (vc-lookup-triple file oldvers))
2590 (setq newvers (vc-lookup-triple file newvers))
2591 (setq options (append (list (and cmp "--brief") "-q"
2592 (and oldvers (concat "-r" oldvers))
2593 (and newvers (concat "-r" newvers)))
2594 (and (not cmp) diff-switches-list)))
2595 (apply 'vc-do-command "*vc-diff*" 1 "vcdiff" file 'MASTER options))
2596 ((eq backend 'RCS)
2597 (if (not oldvers) (setq oldvers (vc-workfile-version file)))
2598 ;; If we know that --brief is not supported, don't try it.
2599 (setq cmp (and cmp (not (eq vc-rcsdiff-knows-brief 'no))))
2600 (setq options (append (list (and cmp "--brief") "-q"
2601 (concat "-r" oldvers)
2602 (and newvers (concat "-r" newvers)))
2603 (and (not cmp) diff-switches-list)))
2604 (setq status (apply 'vc-do-command "*vc-diff*" 2
2605 "rcsdiff" file 'WORKFILE options))
2606 ;; If --brief didn't work, do a double-take and remember it
2607 ;; for the future.
2608 (if (eq status 2)
2609 (prog1
2610 (apply 'vc-do-command "*vc-diff*" 1 "rcsdiff" file 'WORKFILE
2611 (if cmp (cdr options) options))
2612 (if cmp (setq vc-rcsdiff-knows-brief 'no)))
2613 ;; If --brief DID work, remember that, too.
2614 (and cmp (not vc-rcsdiff-knows-brief)
2615 (setq vc-rcsdiff-knows-brief 'yes))
2616 status))
2617 ;; CVS is different.
2618 ((eq backend 'CVS)
2619 (if (string= (vc-workfile-version file) "0")
2620 ;; This file is added but not yet committed; there is no master file.
2621 (if (or oldvers newvers)
2622 (error "No revisions of %s exist" file)
2623 (if cmp 1 ;; file is added but not committed,
2624 ;; we regard this as "changed".
2625 ;; diff it against /dev/null.
2626 (apply 'vc-do-command
2627 "*vc-diff*" 1 "diff" file 'WORKFILE
2628 (append (if (listp diff-switches)
2629 diff-switches
2630 (list diff-switches)) '("/dev/null")))))
2631 ;; cmp is not yet implemented -- we always do a full diff.
2632 (apply 'vc-do-command
2633 "*vc-diff*" 1 "cvs" file 'WORKFILE "diff"
2634 (and oldvers (concat "-r" oldvers))
2635 (and newvers (concat "-r" newvers))
2636 (if (listp diff-switches)
2637 diff-switches
2638 (list diff-switches)))))
2639 (t
2640 (vc-registration-error file)))))
2642 (defun vc-backend-merge-news (file)
2643 ;; Merge in any new changes made to FILE.
2644 (message "Merging changes into %s..." file)
2645 (prog1
2646 (vc-backend-dispatch
2647 file
2648 (error "vc-backend-merge-news not meaningful for SCCS files") ;SCCS
2649 (error "vc-backend-merge-news not meaningful for RCS files") ;RCS
2650 (save-excursion ; CVS
2651 (vc-file-clear-masterprops file)
2652 (vc-file-setprop file 'vc-workfile-version nil)
2653 (vc-file-setprop file 'vc-locking-user nil)
2654 (vc-do-command nil 0 "cvs" file 'WORKFILE "update")
2655 ;; CVS doesn't return an error code if conflicts are detected.
2656 ;; Since we want to warn the user about it (and possibly start
2657 ;; emerge later), scan the output and see if this occurred.
2658 (set-buffer (get-buffer "*vc*"))
2659 (goto-char (point-min))
2660 (if (re-search-forward "^cvs update: conflicts found in .*" nil t)
2661 1 ;; error code for caller
2662 0 ;; no conflict detected
2663 )))
2664 (message "Merging changes into %s...done" file)))
2666 (defun vc-check-headers ()
2667 "Check if the current file has any headers in it."
2668 (interactive)
2669 (save-excursion
2670 (goto-char (point-min))
2671 (vc-backend-dispatch buffer-file-name
2672 (re-search-forward "%[MIRLBSDHTEGUYFPQCZWA]%" nil t) ;; SCCS
2673 (re-search-forward "\\$[A-Za-z\300-\326\330-\366\370-\377]+\\(: [\t -#%-\176\240-\377]*\\)?\\$" nil t) ;; RCS
2674 'RCS ;; CVS works like RCS in this regard.
2675 )
2676 ))
2678 ;; Back-end-dependent stuff ends here.
2680 ;; Set up key bindings for use while editing log messages
2682 (defun vc-log-mode (&optional file)
2683 "Minor mode for driving version-control tools.
2684 These bindings are added to the global keymap when you enter this mode:
2698 While you are entering a change log message for a version, the following
2699 additional bindings will be in effect.
2703 Whenever you do a checkin, your log comment is added to a ring of
2704 saved comments. These can be recalled as follows:
2711 Entry to the change-log submode calls the value of text-mode-hook, then
2712 the value of vc-log-mode-hook.
2714 Global user options:
2715 vc-initial-comment If non-nil, require user to enter a change
2716 comment upon first checkin of the file.
2718 vc-keep-workfiles Non-nil value prevents workfiles from being
2719 deleted when changes are checked in
2721 vc-suppress-confirm Suppresses some confirmation prompts,
2722 notably for reversions.
2724 vc-header-alist Which keywords to insert when adding headers
2727 RCS and CVS.
2729 vc-static-header-alist By default, version headers inserted in C files
2730 get stuffed in a static string area so that
2731 ident(RCS/CVS) or what(SCCS) can see them in
2732 the compiled object code. You can override
2733 this by setting this variable to nil, or change
2734 the header template by changing it.
2736 vc-command-messages if non-nil, display run messages from the
2737 actual version-control utilities (this is
2738 intended primarily for people hacking vc
2739 itself).
2740 "
2741 (interactive)
2742 (set-syntax-table text-mode-syntax-table)
2743 (use-local-map vc-log-entry-mode)
2744 (setq local-abbrev-table text-mode-abbrev-table)
2745 (setq major-mode 'vc-log-mode)
2746 (setq mode-name "VC-Log")
2747 (make-local-variable 'vc-log-file)
2748 (setq vc-log-file file)
2749 (make-local-variable 'vc-log-version)
2750 (make-local-variable 'vc-comment-ring-index)
2751 (set-buffer-modified-p nil)
2752 (setq buffer-file-name nil)
2753 (run-hooks 'text-mode-hook 'vc-log-mode-hook)
2754 )
2756 ;; Initialization code, to be done just once at load-time
2757 (if vc-log-entry-mode
2758 nil
2759 (setq vc-log-entry-mode (make-sparse-keymap))
2760 (define-key vc-log-entry-mode "\M-n" 'vc-next-comment)
2761 (define-key vc-log-entry-mode "\M-p" 'vc-previous-comment)
2762 (define-key vc-log-entry-mode "\M-r" 'vc-comment-search-reverse)
2763 (define-key vc-log-entry-mode "\M-s" 'vc-comment-search-forward)
2764 (define-key vc-log-entry-mode "\C-c\C-c" 'vc-finish-logentry)
2765 )
2767 ;;; These things should probably be generally available
2769 (defun vc-file-tree-walk (dirname func &rest args)
2770 "Walk recursively through DIRNAME.
2771 Invoke FUNC f ARGS on each non-directory file f underneath it."
2772 (vc-file-tree-walk-internal (expand-file-name dirname) func args)
2773 (message "Traversing directory %s...done" dirname))
2775 (defun vc-file-tree-walk-internal (file func args)
2776 (if (not (file-directory-p file))
2777 (apply func file args)
2778 (message "Traversing directory %s..." (abbreviate-file-name file))
2779 (let ((dir (file-name-as-directory file)))
2780 (mapcar
2781 (function
2782 (lambda (f) (or
2783 (string-equal f ".")
2784 (string-equal f "..")
2785 (member f vc-directory-exclusion-list)
2786 (let ((dirf (concat dir f)))
2787 (or
2788 (file-symlink-p dirf) ;; Avoid possible loops
2789 (vc-file-tree-walk-internal dirf func args))))))
2790 (directory-files dir)))))
2792 (provide 'vc)
2794 ;;; DEVELOPER'S NOTES ON CONCURRENCY PROBLEMS IN THIS CODE
2795 ;;;
2796 ;;; These may be useful to anyone who has to debug or extend the package.
2797 ;;; (Note that this information corresponds to versions 5.x. Some of it
2798 ;;; might have been invalidated by the additions to support branching
2799 ;;; and RCS keyword lookup. AS, 1995/03/24)
2800 ;;;
2801 ;;; A fundamental problem in VC is that there are time windows between
2802 ;;; vc-next-action's computations of the file's version-control state and
2803 ;;; the actions that change it. This is a window open to lossage in a
2804 ;;; multi-user environment; someone else could nip in and change the state
2805 ;;; of the master during it.
2806 ;;;
2807 ;;; The performance problem is that rlog/prs calls are very expensive; we want
2808 ;;; to avoid them as much as possible.
2809 ;;;
2810 ;;; ANALYSIS:
2811 ;;;
2812 ;;; The performance problem, it turns out, simplifies in practice to the
2813 ;;; problem of making vc-locking-user fast. The two other functions that call
2814 ;;; prs/rlog will not be so commonly used that the slowdown is a problem; one
2815 ;;; makes snapshots, the other deletes the calling user's last change in the
2816 ;;; master.
2817 ;;;
2818 ;;; The race condition implies that we have to either (a) lock the master
2819 ;;; during the entire execution of vc-next-action, or (b) detect and
2820 ;;; recover from errors resulting from dispatch on an out-of-date state.
2821 ;;;
2822 ;;; Alternative (a) appears to be infeasible. The problem is that we can't
2823 ;;; guarantee that the lock will ever be removed. Suppose a user starts a
2824 ;;; checkin, the change message buffer pops up, and the user, having wandered
2825 ;;; off to do something else, simply forgets about it?
2826 ;;;
2827 ;;; Alternative (b), on the other hand, works well with a cheap way to speed up
2828 ;;; vc-locking-user. Usually, if a file is registered, we can read its locked/
2829 ;;; unlocked state and its current owner from its permissions.
2830 ;;;
2831 ;;; This shortcut will fail if someone has manually changed the workfile's
2832 ;;; permissions; also if developers are munging the workfile in several
2833 ;;; directories, with symlinks to a master (in this latter case, the
2834 ;;; permissions shortcut will fail to detect a lock asserted from another
2835 ;;; directory).
2836 ;;;
2837 ;;; Note that these cases correspond exactly to the errors which could happen
2838 ;;; because of a competing checkin/checkout race in between two instances of
2839 ;;; vc-next-action.
2840 ;;;
2841 ;;; For VC's purposes, a workfile/master pair may have the following states:
2842 ;;;
2843 ;;; A. Unregistered. There is a workfile, there is no master.
2844 ;;;
2845 ;;; B. Registered and not locked by anyone.
2846 ;;;
2847 ;;; C. Locked by calling user and unchanged.
2848 ;;;
2849 ;;; D. Locked by the calling user and changed.
2850 ;;;
2851 ;;; E. Locked by someone other than the calling user.
2852 ;;;
2853 ;;; This makes for 25 states and 20 error conditions. Here's the matrix:
2854 ;;;
2855 ;;; VC's idea of state
2856 ;;; |
2857 ;;; V Actual state RCS action SCCS action Effect
2858 ;;; A B C D E
2859 ;;; A . 1 2 3 4 ci -u -t- admin -fb -i<file> initial admin
2860 ;;; B 5 . 6 7 8 co -l get -e checkout
2861 ;;; C 9 10 . 11 12 co -u unget; get revert
2862 ;;; D 13 14 15 . 16 ci -u -m<comment> delta -y<comment>; get checkin
2863 ;;; E 17 18 19 20 . rcs -u -M -l unget -n ; get -g steal lock
2864 ;;;
2865 ;;; All commands take the master file name as a last argument (not shown).
2866 ;;;
2867 ;;; In the discussion below, a "self-race" is a pathological situation in
2868 ;;; which VC operations are being attempted simultaneously by two or more
2869 ;;; Emacsen running under the same username.
2870 ;;;
2871 ;;; The vc-next-action code has the following windows:
2872 ;;;
2873 ;;; Window P:
2874 ;;; Between the check for existence of a master file and the call to
2875 ;;; admin/checkin in vc-buffer-admin (apparent state A). This window may
2876 ;;; never close if the initial-comment feature is on.
2877 ;;;
2878 ;;; Window Q:
2879 ;;; Between the call to vc-workfile-unchanged-p in and the immediately
2880 ;;; following revert (apparent state C).
2881 ;;;
2882 ;;; Window R:
2883 ;;; Between the call to vc-workfile-unchanged-p in and the following
2884 ;;; checkin (apparent state D). This window may never close.
2885 ;;;
2886 ;;; Window S:
2887 ;;; Between the unlock and the immediately following checkout during a
2888 ;;; revert operation (apparent state C). Included in window Q.
2889 ;;;
2890 ;;; Window T:
2891 ;;; Between vc-locking-user and the following checkout (apparent state B).
2892 ;;;
2893 ;;; Window U:
2894 ;;; Between vc-locking-user and the following revert (apparent state C).
2895 ;;; Includes windows Q and S.
2896 ;;;
2897 ;;; Window V:
2898 ;;; Between vc-locking-user and the following checkin (apparent state
2899 ;;; D). This window may never be closed if the user fails to complete the
2900 ;;; checkin message. Includes window R.
2901 ;;;
2902 ;;; Window W:
2903 ;;; Between vc-locking-user and the following steal-lock (apparent
2904 ;;; state E). This window may never close if the user fails to complete
2905 ;;; the steal-lock message. Includes window X.
2906 ;;;
2907 ;;; Window X:
2908 ;;; Between the unlock and the immediately following re-lock during a
2909 ;;; steal-lock operation (apparent state E). This window may never cloce
2910 ;;; if the user fails to complete the steal-lock message.
2911 ;;;
2912 ;;; Errors:
2913 ;;;
2914 ;;; Apparent state A ---
2915 ;;;
2916 ;;; 1. File looked unregistered but is actually registered and not locked.
2917 ;;;
2918 ;;; Potential cause: someone else's admin during window P, with
2919 ;;; caller's admin happening before their checkout.
2920 ;;;
2921 ;;; RCS: Prior to version 5.6.4, ci fails with message
2922 ;;; "no lock set by <user>". From 5.6.4 onwards, VC uses the new
2923 ;;; ci -i option and the message is "<file>,v: already exists".
2924 ;;; SCCS: admin will fail with error (ad19).
2925 ;;;
2926 ;;; We can let these errors be passed up to the user.
2927 ;;;
2928 ;;; 2. File looked unregistered but is actually locked by caller, unchanged.
2929 ;;;
2930 ;;; Potential cause: self-race during window P.
2931 ;;;
2932 ;;; RCS: Prior to version 5.6.4, reverts the file to the last saved
2933 ;;; version and unlocks it. From 5.6.4 onwards, VC uses the new
2934 ;;; ci -i option, failing with message "<file>,v: already exists".
2935 ;;; SCCS: will fail with error (ad19).
2936 ;;;
2937 ;;; Either of these consequences is acceptable.
2938 ;;;
2939 ;;; 3. File looked unregistered but is actually locked by caller, changed.
2940 ;;;
2941 ;;; Potential cause: self-race during window P.
2942 ;;;
2943 ;;; RCS: Prior to version 5.6.4, VC registers the caller's workfile as
2944 ;;; a delta with a null change comment (the -t- switch will be
2945 ;;; ignored). From 5.6.4 onwards, VC uses the new ci -i option,
2946 ;;; failing with message "<file>,v: already exists".
2947 ;;; SCCS: will fail with error (ad19).
2948 ;;;
2949 ;;; 4. File looked unregistered but is locked by someone else.
2950 ;;;
2951 ;;; Potential cause: someone else's admin during window P, with
2952 ;;; caller's admin happening *after* their checkout.
2953 ;;;
2954 ;;; RCS: Prior to version 5.6.4, ci fails with a
2955 ;;; "no lock set by <user>" message. From 5.6.4 onwards,
2956 ;;; VC uses the new ci -i option, failing with message
2957 ;;; "<file>,v: already exists".
2958 ;;; SCCS: will fail with error (ad19).
2959 ;;;
2960 ;;; We can let these errors be passed up to the user.
2961 ;;;
2962 ;;; Apparent state B ---
2963 ;;;
2964 ;;; 5. File looked registered and not locked, but is actually unregistered.
2965 ;;;
2966 ;;; Potential cause: master file got nuked during window P.
2967 ;;;
2968 ;;; RCS: will fail with "RCS/<file>: No such file or directory"
2969 ;;; SCCS: will fail with error ut4.
2970 ;;;
2971 ;;; We can let these errors be passed up to the user.
2972 ;;;
2973 ;;; 6. File looked registered and not locked, but is actually locked by the
2974 ;;; calling user and unchanged.
2975 ;;;
2976 ;;; Potential cause: self-race during window T.
2977 ;;;
2978 ;;; RCS: in the same directory as the previous workfile, co -l will fail
2979 ;;; with "co error: writable foo exists; checkout aborted". In any other
2980 ;;; directory, checkout will succeed.
2981 ;;; SCCS: will fail with ge17.
2982 ;;;
2983 ;;; Either of these consequences is acceptable.
2984 ;;;
2985 ;;; 7. File looked registered and not locked, but is actually locked by the
2986 ;;; calling user and changed.
2987 ;;;
2988 ;;; As case 6.
2989 ;;;
2990 ;;; 8. File looked registered and not locked, but is actually locked by another
2991 ;;; user.
2992 ;;;
2993 ;;; Potential cause: someone else checks it out during window T.
2994 ;;;
2995 ;;; RCS: co error: revision 1.3 already locked by <user>
2996 ;;; SCCS: fails with ge4 (in directory) or ut7 (outside it).
2997 ;;;
2998 ;;; We can let these errors be passed up to the user.
2999 ;;;
3000 ;;; Apparent state C ---
3001 ;;;
3002 ;;; 9. File looks locked by calling user and unchanged, but is unregistered.
3003 ;;;
3004 ;;; As case 5.
3005 ;;;
3006 ;;; 10. File looks locked by calling user and unchanged, but is actually not
3007 ;;; locked.
3008 ;;;
3009 ;;; Potential cause: a self-race in window U, or by the revert's
3010 ;;; landing during window X of some other user's steal-lock or window S
3011 ;;; of another user's revert.
3012 ;;;
3013 ;;; RCS: succeeds, refreshing the file from the identical version in
3014 ;;; the master.
3015 ;;; SCCS: fails with error ut4 (p file nonexistent).
3016 ;;;
3017 ;;; Either of these consequences is acceptable.
3018 ;;;
3019 ;;; 11. File is locked by calling user. It looks unchanged, but is actually
3020 ;;; changed.
3021 ;;;
3022 ;;; Potential cause: the file would have to be touched by a self-race
3023 ;;; during window Q.
3024 ;;;
3025 ;;; The revert will succeed, removing whatever changes came with
3026 ;;; the touch. It is theoretically possible that work could be lost.
3027 ;;;
3028 ;;; 12. File looks like it's locked by the calling user and unchanged, but
3029 ;;; it's actually locked by someone else.
3030 ;;;
3031 ;;; Potential cause: a steal-lock in window V.
3032 ;;;
3033 ;;; RCS: co error: revision <rev> locked by <user>; use co -r or rcs -u
3034 ;;; SCCS: fails with error un2
3035 ;;;
3036 ;;; We can pass these errors up to the user.
3037 ;;;
3038 ;;; Apparent state D ---
3039 ;;;
3040 ;;; 13. File looks like it's locked by the calling user and changed, but it's
3041 ;;; actually unregistered.
3042 ;;;
3043 ;;; Potential cause: master file got nuked during window P.
3044 ;;;
3045 ;;; RCS: Prior to version 5.6.4, checks in the user's version as an
3046 ;;; initial delta. From 5.6.4 onwards, VC uses the new ci -j
3047 ;;; option, failing with message "no such file or directory".
3048 ;;; SCCS: will fail with error ut4.
3049 ;;;
3050 ;;; This case is kind of nasty. Under RCS prior to version 5.6.4,
3051 ;;; VC may fail to detect the loss of previous version information.
3052 ;;;
3053 ;;; 14. File looks like it's locked by the calling user and changed, but it's
3054 ;;; actually unlocked.
3055 ;;;
3056 ;;; Potential cause: self-race in window V, or the checkin happening
3057 ;;; during the window X of someone else's steal-lock or window S of
3058 ;;; someone else's revert.
3059 ;;;
3060 ;;; RCS: ci will fail with "no lock set by <user>".
3061 ;;; SCCS: delta will fail with error ut4.
3062 ;;;
3063 ;;; 15. File looks like it's locked by the calling user and changed, but it's
3064 ;;; actually locked by the calling user and unchanged.
3065 ;;;
3066 ;;; Potential cause: another self-race --- a whole checkin/checkout
3067 ;;; sequence by the calling user would have to land in window R.
3068 ;;;
3069 ;;; SCCS: checks in a redundant delta and leaves the file unlocked as usual.
3070 ;;; RCS: reverts to the file state as of the second user's checkin, leaving
3071 ;;; the file unlocked.
3072 ;;;
3073 ;;; It is theoretically possible that work could be lost under RCS.
3074 ;;;
3075 ;;; 16. File looks like it's locked by the calling user and changed, but it's
3076 ;;; actually locked by a different user.
3077 ;;;
3078 ;;; RCS: ci error: no lock set by <user>
3079 ;;; SCCS: unget will fail with error un2
3080 ;;;
3081 ;;; We can pass these errors up to the user.
3082 ;;;
3083 ;;; Apparent state E ---
3084 ;;;
3085 ;;; 17. File looks like it's locked by some other user, but it's actually
3086 ;;; unregistered.
3087 ;;;
3088 ;;; As case 13.
3089 ;;;
3090 ;;; 18. File looks like it's locked by some other user, but it's actually
3091 ;;; unlocked.
3092 ;;;
3093 ;;; Potential cause: someone released a lock during window W.
3094 ;;;
3095 ;;; RCS: The calling user will get the lock on the file.
3096 ;;; SCCS: unget -n will fail with cm4.
3097 ;;;
3098 ;;; Either of these consequences will be OK.
3099 ;;;
3100 ;;; 19. File looks like it's locked by some other user, but it's actually
3101 ;;; locked by the calling user and unchanged.
3102 ;;;
3103 ;;; Potential cause: the other user relinquishing a lock followed by
3104 ;;; a self-race, both in window W.
3105 ;;;
3106 ;;; Under both RCS and SCCS, both unlock and lock will succeed, making
3107 ;;; the sequence a no-op.
3108 ;;;
3109 ;;; 20. File looks like it's locked by some other user, but it's actually
3110 ;;; locked by the calling user and changed.
3111 ;;;
3112 ;;; As case 19.
3113 ;;;
3114 ;;; PROBLEM CASES:
3115 ;;;
3116 ;;; In order of decreasing severity:
3117 ;;;
3118 ;;; Cases 11 and 15 are the only ones that potentially lose work.
3119 ;;; They would require a self-race for this to happen.
3120 ;;;
3121 ;;; Case 13 in RCS loses information about previous deltas, retaining
3122 ;;; only the information in the current workfile. This can only happen
3123 ;;; if the master file gets nuked in window P.
3124 ;;;
3125 ;;; Case 3 in RCS and case 15 under SCCS insert a redundant delta with
3126 ;;; no change comment in the master. This would require a self-race in
3127 ;;; window P or R respectively.
3128 ;;;
3129 ;;; Cases 2, 10, 19 and 20 do extra work, but make no changes.
3130 ;;;
3131 ;;; Unfortunately, it appears to me that no recovery is possible in these
3132 ;;; cases. They don't yield error messages, so there's no way to tell that
3133 ;;; a race condition has occurred.
3134 ;;;
3135 ;;; All other cases don't change either the workfile or the master, and
3136 ;;; trigger command errors which the user will see.
3137 ;;;
3138 ;;; Thus, there is no explicit recovery code.
3140 ;;; vc.el ends here