gnu/usr.bin/rcs/co/co.c

   1 /* Check out working files from revisions of RCS files.  */
   2
   3 /* Copyright 1982, 1988, 1989 Walter Tichy
   4    Copyright 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert
   5    Distributed under license by the Free Software Foundation, Inc.
   6
   7 This file is part of RCS.
   8
   9 RCS is free software; you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation; either version 2, or (at your option)
  12 any later version.
  13
  14 RCS is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with RCS; see the file COPYING.
  21 If not, write to the Free Software Foundation,
  22 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  23
  24 Report problems and direct all questions to:
  25
  26     rcs-bugs@cs.purdue.edu
  27
  28 */
  29
  30 /*
  31  * $FreeBSD: src/gnu/usr.bin/rcs/co/co.c,v 1.10 1999/08/27 23:36:40 peter Exp $
  32  * $DragonFly: src/gnu/usr.bin/rcs/co/co.c,v 1.2 2003/06/17 04:25:47 dillon Exp $
  33  *
  34  * Revision 5.18  1995/06/16 06:19:24  eggert
  35  * Update FSF address.
  36  *
  37  * Revision 5.17  1995/06/01 16:23:43  eggert
  38  * (main, preparejoin): Pass argument instead of using `join' static variable.
  39  * (main): Add -kb.
  40  *
  41  * Revision 5.16  1994/03/17 14:05:48  eggert
  42  * Move buffer-flushes out of critical sections, since they aren't critical.
  43  * Use ORCSerror to clean up after a fatal error.  Remove lint.
  44  * Specify subprocess input via file descriptor, not file name.
  45  *
  46  * Revision 5.15  1993/11/09 17:40:15  eggert
  47  * -V now prints version on stdout and exits.  Don't print usage twice.
  48  *
  49  * Revision 5.14  1993/11/03 17:42:27  eggert
  50  * Add -z.  Generate a value for the Name keyword.
  51  * Don't arbitrarily limit the number of joins.
  52  * Improve quality of diagnostics.
  53  *
  54  * Revision 5.13  1992/07/28  16:12:44  eggert
  55  * Add -V.  Check that working and RCS files are distinct.
  56  *
  57  * Revision 5.12  1992/02/17  23:02:08  eggert
  58  * Add -T.
  59  *
  60  * Revision 5.11  1992/01/24  18:44:19  eggert
  61  * Add support for bad_creat0.  lint -> RCS_lint
  62  *
  63  * Revision 5.10  1992/01/06  02:42:34  eggert
  64  * Update usage string.
  65  *
  66  * Revision 5.9  1991/10/07  17:32:46  eggert
  67  * -k affects just working file, not RCS file.
  68  *
  69  * Revision 5.8  1991/08/19  03:13:55  eggert
  70  * Warn before removing somebody else's file.
  71  * Add -M.  Fix co -j bugs.  Tune.
  72  *
  73  * Revision 5.7  1991/04/21  11:58:15  eggert
  74  * Ensure that working file is newer than RCS file after co -[lu].
  75  * Add -x, RCSINIT, MS-DOS support.
  76  *
  77  * Revision 5.6  1990/12/04  05:18:38  eggert
  78  * Don't checkaccesslist() unless necessary.
  79  * Use -I for prompts and -q for diagnostics.
  80  *
  81  * Revision 5.5  1990/11/01  05:03:26  eggert
  82  * Fix -j.  Add -I.
  83  *
  84  * Revision 5.4  1990/10/04  06:30:11  eggert
  85  * Accumulate exit status across files.
  86  *
  87  * Revision 5.3  1990/09/11  02:41:09  eggert
  88  * co -kv yields a readonly working file.
  89  *
  90  * Revision 5.2  1990/09/04  08:02:13  eggert
  91  * Standardize yes-or-no procedure.
  92  *
  93  * Revision 5.0  1990/08/22  08:10:02  eggert
  94  * Permit multiple locks by same user.  Add setuid support.
  95  * Remove compile-time limits; use malloc instead.
  96  * Permit dates past 1999/12/31.  Switch to GMT.
  97  * Make lock and temp files faster and safer.
  98  * Ansify and Posixate.  Add -k, -V.  Remove snooping.  Tune.
  99  *
 100  * Revision 4.7  89/05/01  15:11:41  narten
 101  * changed copyright header to reflect current distribution rules
 102  *
 103  * Revision 4.6  88/08/09  19:12:15  eggert
 104  * Fix "co -d" core dump; rawdate wasn't always initialized.
 105  * Use execv(), not system(); fix putchar('\0') and diagnose() botches; remove lint
 106  *
 107  * Revision 4.5  87/12/18  11:35:40  narten
 108  * lint cleanups (from Guy Harris)
 109  *
 110  * Revision 4.4  87/10/18  10:20:53  narten
 111  * Updating version numbers changes relative to 1.1, are actually
 112  * relative to 4.2
 113  *
 114  * Revision 1.3  87/09/24  13:58:30  narten
 115  * Sources now pass through lint (if you ignore printf/sprintf/fprintf
 116  * warnings)
 117  *
 118  * Revision 1.2  87/03/27  14:21:38  jenkins
 119  * Port to suns
 120  *
 121  * Revision 4.2  83/12/05  13:39:48  wft
 122  * made rewriteflag external.
 123  *
 124  * Revision 4.1  83/05/10  16:52:55  wft
 125  * Added option -u and -f.
 126  * Added handling of default branch.
 127  * Replaced getpwuid() with getcaller().
 128  * Removed calls to stat(); now done by pairfilenames().
 129  * Changed and renamed rmoldfile() to rmworkfile().
 130  * Replaced catchints() calls with restoreints(), unlink()--link() with rename();
 131  *
 132  * Revision 3.7  83/02/15  15:27:07  wft
 133  * Added call to fastcopy() to copy remainder of RCS file.
 134  *
 135  * Revision 3.6  83/01/15  14:37:50  wft
 136  * Added ignoring of interrupts while RCS file is renamed; this avoids
 137  * deletion of RCS files during the unlink/link window.
 138  *
 139  * Revision 3.5  82/12/08  21:40:11  wft
 140  * changed processing of -d to use DATEFORM; removed actual from
 141  * call to preparejoin; re-fixed printing of done at the end.
 142  *
 143  * Revision 3.4  82/12/04  18:40:00  wft
 144  * Replaced getdelta() with gettree(), SNOOPDIR with SNOOPFILE.
 145  * Fixed printing of "done".
 146  *
 147  * Revision 3.3  82/11/28  22:23:11  wft
 148  * Replaced getlogin() with getpwuid(), flcose() with ffclose(),
 149  * %02d with %.2d, mode generation for working file with WORKMODE.
 150  * Fixed nil printing. Fixed -j combined with -l and -p, and exit
 151  * for non-existing revisions in preparejoin().
 152  *
 153  * Revision 3.2  82/10/18  20:47:21  wft
 154  * Mode of working file is now maintained even for co -l, but write permission
 155  * is removed.
 156  * The working file inherits its mode from the RCS file, plus write permission
 157  * for the owner. The write permission is not given if locking is strict and
 158  * co does not lock.
 159  * An existing working file without write permission is deleted automatically.
 160  * Otherwise, co asks (empty answer: abort co).
 161  * Call to getfullRCSname() added, check for write error added, call
 162  * for getlogin() fixed.
 163  *
 164  * Revision 3.1  82/10/13  16:01:30  wft
 165  * fixed type of variables receiving from getc() (char -> int).
 166  * removed unused variables.
 167  */
 168
 169
 170
 171
 172 #include "rcsbase.h"
 173
 174 static char *addjoin P((char*));
 175 static char const *getancestor P((char const*,char const*));
 176 static int buildjoin P((char const*));
 177 static int preparejoin P((char*));
 178 static int rmlock P((struct hshentry const*));
 179 static int rmworkfile P((void));
 180 static void cleanup P((void));
 181
 182 static char const quietarg[] = "-q";
 183
 184 static char const *expandarg, *suffixarg, *versionarg, *zonearg;
 185 static char const **joinlist; /* revisions to be joined */
 186 static int joinlength;
 187 static FILE *neworkptr;
 188 static int exitstatus;
 189 static int forceflag;
 190 static int lastjoin;                    /* index of last element in joinlist  */
 191 static int lockflag; /* -1 -> unlock, 0 -> do nothing, 1 -> lock */
 192 static int mtimeflag;
 193 static struct hshentries *gendeltas;    /* deltas to be generated       */
 194 static struct hshentry *targetdelta;    /* final delta to be generated  */
 195 static struct stat workstat;
 196
 197 mainProg(coId, "co", "$DragonFly: src/gnu/usr.bin/rcs/co/co.c,v 1.2 2003/06/17 04:25:47 dillon Exp $")
 198 {
 199         static char const cmdusage[] =
 200                 "\nco usage: co -{fIlMpqru}[rev] -ddate -jjoins -ksubst -sstate -T -w[who] -Vn -xsuff -zzone file ...";
 201
 202         char *a, *joinflag, **newargv;
 203         char const *author, *date, *rev, *state;
 204         char const *joinname, *newdate, *neworkname;
 205         int changelock;  /* 1 if a lock has been changed, -1 if error */
 206         int expmode, r, tostdout, workstatstat;
 207         int Ttimeflag;
 208         struct buf numericrev;  /* expanded revision number     */
 209         char finaldate[datesize];
 210 #       if OPEN_O_BINARY
 211                 int stdout_mode = 0;
 212 #       endif
 213
 214         setrid();
 215         author = date = rev = state = 0;
 216         joinflag = 0;
 217         bufautobegin(&numericrev);
 218         expmode = -1;
 219         suffixes = X_DEFAULT;
 220         tostdout = false;
 221         Ttimeflag = false;
 222
 223         argc = getRCSINIT(argc, argv, &newargv);
 224         argv = newargv;
 225         while (a = *++argv,  0<--argc && *a++=='-') {
 226                 switch (*a++) {
 227
 228                 case 'r':
 229                 revno:
 230                         if (*a) {
 231                                 if (rev) warn("redefinition of revision number");
 232                                 rev = a;
 233                         }
 234                         break;
 235
 236                 case 'f':
 237                         forceflag=true;
 238                         goto revno;
 239
 240                 case 'l':
 241                         if (lockflag < 0) {
 242                                 warn("-u overridden by -l.");
 243                         }
 244                         lockflag = 1;
 245                         goto revno;
 246
 247                 case 'u':
 248                         if (0 < lockflag) {
 249                                 warn("-l overridden by -u.");
 250                         }
 251                         lockflag = -1;
 252                         goto revno;
 253
 254                 case 'p':
 255                         tostdout = true;
 256                         goto revno;
 257
 258                 case 'I':
 259                         interactiveflag = true;
 260                         goto revno;
 261
 262                 case 'q':
 263                         quietflag=true;
 264                         goto revno;
 265
 266                 case 'd':
 267                         if (date)
 268                                 redefined('d');
 269                         str2date(a, finaldate);
 270                         date=finaldate;
 271                         break;
 272
 273                 case 'j':
 274                         if (*a) {
 275                                 if (joinflag) redefined('j');
 276                                 joinflag = a;
 277                         }
 278                         break;
 279
 280                 case 'M':
 281                         mtimeflag = true;
 282                         goto revno;
 283
 284                 case 's':
 285                         if (*a) {
 286                                 if (state) redefined('s');
 287                                 state = a;
 288                         }
 289                         break;
 290
 291                 case 'T':
 292                         if (*a)
 293                                 goto unknown;
 294                         Ttimeflag = true;
 295                         break;
 296
 297                 case 'w':
 298                         if (author) redefined('w');
 299                         if (*a)
 300                                 author = a;
 301                         else
 302                                 author = getcaller();
 303                         break;
 304
 305                 case 'x':
 306                         suffixarg = *argv;
 307                         suffixes = a;
 308                         break;
 309
 310                 case 'V':
 311                         versionarg = *argv;
 312                         setRCSversion(versionarg);
 313                         break;
 314
 315                 case 'z':
 316                         zonearg = *argv;
 317                         zone_set(a);
 318                         break;
 319
 320                 case 'k':    /*  set keyword expand mode  */
 321                         expandarg = *argv;
 322                         if (0 <= expmode) redefined('k');
 323                         if (0 <= (expmode = str2expmode(a)))
 324                             break;
 325                         /* fall into */
 326                 default:
 327                 unknown:
 328                         error("unknown option: %s%s", *argv, cmdusage);
 329
 330                 };
 331         } /* end of option processing */
 332
 333         /* Now handle all pathnames.  */
 334         if (nerror) cleanup();
 335         else if (argc < 1) faterror("no input file%s", cmdusage);
 336         else for (;  0 < argc;  cleanup(), ++argv, --argc) {
 337         ffree();
 338
 339         if (pairnames(argc, argv, lockflag?rcswriteopen:rcsreadopen, true, false)  <=  0)
 340                 continue;
 341
 342         /*
 343          * RCSname contains the name of the RCS file, and finptr
 344          * points at it.  workname contains the name of the working file.
 345          * Also, RCSstat has been set.
 346          */
 347         diagnose("%s  -->  %s\n", RCSname, tostdout?"standard output":workname);
 348
 349         workstatstat = -1;
 350         if (tostdout) {
 351 #               if OPEN_O_BINARY
 352                     int newmode = Expand==BINARY_EXPAND ? OPEN_O_BINARY : 0;
 353                     if (stdout_mode != newmode) {
 354                         stdout_mode = newmode;
 355                         oflush();
 356                         VOID setmode(STDOUT_FILENO, newmode);
 357                     }
 358 #               endif
 359                 neworkname = 0;
 360                 neworkptr = workstdout = stdout;
 361         } else {
 362                 workstatstat = stat(workname, &workstat);
 363                 if (workstatstat == 0  &&  same_file(RCSstat, workstat, 0)) {
 364                         rcserror("RCS file is the same as working file %s.",
 365                                 workname
 366                         );
 367                         continue;
 368                 }
 369                 neworkname = makedirtemp(1);
 370                 if (!(neworkptr = fopenSafer(neworkname, FOPEN_W_WORK))) {
 371                         if (errno == EACCES)
 372                             workerror("permission denied on parent directory");
 373                         else
 374                             eerror(neworkname);
 375                         continue;
 376                 }
 377         }
 378
 379         gettree();  /* reads in the delta tree */
 380
 381         if (!Head) {
 382                 /* no revisions; create empty file */
 383                 diagnose("no revisions present; generating empty revision 0.0\n");
 384                 if (lockflag)
 385                         warn(
 386                                 "no revisions, so nothing can be %slocked",
 387                                 lockflag < 0 ? "un" : ""
 388                         );
 389                 Ozclose(&fcopy);
 390                 if (workstatstat == 0)
 391                         if (!rmworkfile()) continue;
 392                 changelock = 0;
 393                 newdate = 0;
 394         } else {
 395                 int locks = lockflag ? findlock(false, &targetdelta) : 0;
 396                 if (rev) {
 397                         /* expand symbolic revision number */
 398                         if (!expandsym(rev, &numericrev))
 399                                 continue;
 400                 } else {
 401                         switch (locks) {
 402                             default:
 403                                 continue;
 404                             case 0:
 405                                 bufscpy(&numericrev, Dbranch?Dbranch:"");
 406                                 break;
 407                             case 1:
 408                                 bufscpy(&numericrev, targetdelta->num);
 409                                 break;
 410                         }
 411                 }
 412                 /* get numbers of deltas to be generated */
 413                 if (!(targetdelta=genrevs(numericrev.string,date,author,state,&gendeltas)))
 414                         continue;
 415                 /* check reservations */
 416                 changelock =
 417                         lockflag < 0 ?
 418                                 rmlock(targetdelta)
 419                         : lockflag == 0 ?
 420                                 0
 421                         :
 422                                 addlock(targetdelta, true);
 423
 424                 if (
 425                         changelock < 0
 426                         || (changelock && !checkaccesslist())
 427                         || dorewrite(lockflag, changelock) != 0
 428                 )
 429                         continue;
 430
 431                 if (0 <= expmode)
 432                         Expand = expmode;
 433                 if (0 < lockflag  &&  Expand == VAL_EXPAND) {
 434                         rcserror("cannot combine -kv and -l");
 435                         continue;
 436                 }
 437
 438                 if (joinflag && !preparejoin(joinflag))
 439                         continue;
 440
 441                 diagnose("revision %s%s\n",targetdelta->num,
 442                          0<lockflag ? " (locked)" :
 443                          lockflag<0 ? " (unlocked)" : "");
 444
 445                 /* Prepare to remove old working file if necessary.  */
 446                 if (workstatstat == 0)
 447                         if (!rmworkfile()) continue;
 448
 449                 /* skip description */
 450                 getdesc(false); /* don't echo*/
 451
 452                 locker_expansion = 0 < lockflag;
 453                 targetdelta->name = namedrev(rev, targetdelta);
 454                 joinname = buildrevision(
 455                         gendeltas, targetdelta,
 456                         joinflag&&tostdout ? (FILE*)0 : neworkptr,
 457                         Expand < MIN_UNEXPAND
 458                 );
 459 #               if !large_memory
 460                         if (fcopy == neworkptr)
 461                                 fcopy = 0;  /* Don't close it twice.  */
 462 #               endif
 463                 if_advise_access(changelock && gendeltas->first!=targetdelta,
 464                         finptr, MADV_SEQUENTIAL
 465                 );
 466
 467                 if (donerewrite(changelock,
 468                         Ttimeflag ? RCSstat.st_mtime : (time_t)-1
 469                 ) != 0)
 470                         continue;
 471
 472                 if (changelock) {
 473                         locks += lockflag;
 474                         if (1 < locks)
 475                                 rcswarn("You now have %d locks.", locks);
 476                 }
 477
 478                 newdate = targetdelta->date;
 479                 if (joinflag) {
 480                         newdate = 0;
 481                         if (!joinname) {
 482                                 aflush(neworkptr);
 483                                 joinname = neworkname;
 484                         }
 485                         if (Expand == BINARY_EXPAND)
 486                                 workerror("merging binary files");
 487                         if (!buildjoin(joinname))
 488                                 continue;
 489                 }
 490         }
 491         if (!tostdout) {
 492             mode_t m = WORKMODE(RCSstat.st_mode,
 493                 !  (Expand==VAL_EXPAND  ||  (lockflag<=0 && StrictLocks))
 494             );
 495             time_t t = mtimeflag&&newdate ? date2time(newdate) : (time_t)-1;
 496             aflush(neworkptr);
 497             ignoreints();
 498             r = chnamemod(&neworkptr, neworkname, workname, 1, m, t);
 499             keepdirtemp(neworkname);
 500             restoreints();
 501             if (r != 0) {
 502                 eerror(workname);
 503                 error("see %s", neworkname);
 504                 continue;
 505             }
 506             diagnose("done\n");
 507         }
 508         }
 509
 510         tempunlink();
 511         Ofclose(workstdout);
 512         exitmain(exitstatus);
 513
 514 }       /* end of main (co) */
 515
 516         static void
 517 cleanup()
 518 {
 519         if (nerror) exitstatus = EXIT_FAILURE;
 520         Izclose(&finptr);
 521         ORCSclose();
 522 #       if !large_memory
 523                 if (fcopy!=workstdout) Ozclose(&fcopy);
 524 #       endif
 525         if (neworkptr!=workstdout) Ozclose(&neworkptr);
 526         dirtempunlink();
 527 }
 528
 529 #if RCS_lint
 530 #       define exiterr coExit
 531 #endif
 532         void
 533 exiterr()
 534 {
 535         ORCSerror();
 536         dirtempunlink();
 537         tempunlink();
 538         _exit(EXIT_FAILURE);
 539 }
 540
 541
 542 /*****************************************************************
 543  * The following routines are auxiliary routines
 544  *****************************************************************/
 545
 546         static int
 547 rmworkfile()
 548 /*
 549  * Prepare to remove workname, if it exists, and if
 550  * it is read-only.
 551  * Otherwise (file writable):
 552  *   if !quietmode asks the user whether to really delete it (default: fail);
 553  *   otherwise failure.
 554  * Returns true if permission is gotten.
 555  */
 556 {
 557         if (workstat.st_mode&(S_IWUSR|S_IWGRP|S_IWOTH) && !forceflag) {
 558             /* File is writable */
 559             if (!yesorno(false, "writable %s exists%s; remove it? [ny](n): ",
 560                         workname,
 561                         myself(workstat.st_uid) ? "" : ", and you do not own it"
 562             )) {
 563                 error(!quietflag && ttystdin()
 564                         ? "checkout aborted"
 565                         : "writable %s exists; checkout aborted", workname);
 566                 return false;
 567             }
 568         }
 569         /* Actual unlink is done later by caller. */
 570         return true;
 571 }
 572
 573
 574         static int
 575 rmlock(delta)
 576         struct hshentry const *delta;
 577 /* Function: removes the lock held by caller on delta.
 578  * Returns -1 if someone else holds the lock,
 579  * 0 if there is no lock on delta,
 580  * and 1 if a lock was found and removed.
 581  */
 582 {       register struct rcslock * next, * trail;
 583         char const *num;
 584         struct rcslock dummy;
 585         int whomatch, nummatch;
 586
 587         num=delta->num;
 588         dummy.nextlock=next=Locks;
 589         trail = &dummy;
 590         while (next) {
 591                 whomatch = strcmp(getcaller(), next->login);
 592                 nummatch=strcmp(num,next->delta->num);
 593                 if ((whomatch==0) && (nummatch==0)) break;
 594                         /*found a lock on delta by caller*/
 595                 if ((whomatch!=0)&&(nummatch==0)) {
 596                     rcserror("revision %s locked by %s; use co -r or rcs -u",
 597                         num, next->login
 598                     );
 599                     return -1;
 600                 }
 601                 trail=next;
 602                 next=next->nextlock;
 603         }
 604         if (next) {
 605                 /*found one; delete it */
 606                 trail->nextlock=next->nextlock;
 607                 Locks=dummy.nextlock;
 608                 next->delta->lockedby = 0;
 609                 return 1; /*success*/
 610         } else  return 0; /*no lock on delta*/
 611 }
 612
 613
 614
 615
 616 /*****************************************************************
 617  * The rest of the routines are for handling joins
 618  *****************************************************************/
 619
 620
 621         static char *
 622 addjoin(joinrev)
 623         char *joinrev;
 624 /* Add joinrev's number to joinlist, yielding address of char past joinrev,
 625  * or 0 if no such revision exists.
 626  */
 627 {
 628         register char *j;
 629         register struct hshentry *d;
 630         char terminator;
 631         struct buf numrev;
 632         struct hshentries *joindeltas;
 633
 634         j = joinrev;
 635         for (;;) {
 636             switch (*j++) {
 637                 default:
 638                     continue;
 639                 case 0:
 640                 case ' ': case '\t': case '\n':
 641                 case ':': case ',': case ';':
 642                     break;
 643             }
 644             break;
 645         }
 646         terminator = *--j;
 647         *j = 0;
 648         bufautobegin(&numrev);
 649         d = 0;
 650         if (expandsym(joinrev, &numrev))
 651             d = genrevs(numrev.string,(char*)0,(char*)0,(char*)0,&joindeltas);
 652         bufautoend(&numrev);
 653         *j = terminator;
 654         if (d) {
 655                 joinlist[++lastjoin] = d->num;
 656                 return j;
 657         }
 658         return 0;
 659 }
 660
 661         static int
 662 preparejoin(j)
 663         register char *j;
 664 /* Parse join list J and place pointers to the
 665  * revision numbers into joinlist.
 666  */
 667 {
 668         lastjoin= -1;
 669         for (;;) {
 670                 while ((*j==' ')||(*j=='\t')||(*j==',')) j++;
 671                 if (*j=='\0') break;
 672                 if (lastjoin>=joinlength-2) {
 673                     joinlist =
 674                         (joinlength *= 2) == 0
 675                         ? tnalloc(char const *, joinlength = 16)
 676                         : trealloc(char const *, joinlist, joinlength);
 677                 }
 678                 if (!(j = addjoin(j))) return false;
 679                 while ((*j==' ') || (*j=='\t')) j++;
 680                 if (*j == ':') {
 681                         j++;
 682                         while((*j==' ') || (*j=='\t')) j++;
 683                         if (*j!='\0') {
 684                                 if (!(j = addjoin(j))) return false;
 685                         } else {
 686                                 rcsfaterror("join pair incomplete");
 687                         }
 688                 } else {
 689                         if (lastjoin==0) { /* first pair */
 690                                 /* common ancestor missing */
 691                                 joinlist[1]=joinlist[0];
 692                                 lastjoin=1;
 693                                 /*derive common ancestor*/
 694                                 if (!(joinlist[0] = getancestor(targetdelta->num,joinlist[1])))
 695                                        return false;
 696                         } else {
 697                                 rcsfaterror("join pair incomplete");
 698                         }
 699                 }
 700         }
 701         if (lastjoin < 1)
 702                 rcsfaterror("empty join");
 703         return true;
 704 }
 705
 706
 707
 708         static char const *
 709 getancestor(r1, r2)
 710         char const *r1, *r2;
 711 /* Yield the common ancestor of r1 and r2 if successful, 0 otherwise.
 712  * Work reliably only if r1 and r2 are not branch numbers.
 713  */
 714 {
 715         static struct buf t1, t2;
 716
 717         int l1, l2, l3;
 718         char const *r;
 719
 720         l1 = countnumflds(r1);
 721         l2 = countnumflds(r2);
 722         if ((2<l1 || 2<l2)  &&  cmpnum(r1,r2)!=0) {
 723             /* not on main trunk or identical */
 724             l3 = 0;
 725             while (cmpnumfld(r1, r2, l3+1)==0 && cmpnumfld(r1, r2, l3+2)==0)
 726                 l3 += 2;
 727             /* This will terminate since r1 and r2 are not the same; see above. */
 728             if (l3==0) {
 729                 /* no common prefix; common ancestor on main trunk */
 730                 VOID partialno(&t1, r1, l1>2 ? 2 : l1);
 731                 VOID partialno(&t2, r2, l2>2 ? 2 : l2);
 732                 r = cmpnum(t1.string,t2.string)<0 ? t1.string : t2.string;
 733                 if (cmpnum(r,r1)!=0 && cmpnum(r,r2)!=0)
 734                         return r;
 735             } else if (cmpnumfld(r1, r2, l3+1)!=0)
 736                         return partialno(&t1,r1,l3);
 737         }
 738         rcserror("common ancestor of %s and %s undefined", r1, r2);
 739         return 0;
 740 }
 741
 742
 743
 744         static int
 745 buildjoin(initialfile)
 746         char const *initialfile;
 747 /* Function: merge pairs of elements in joinlist into initialfile
 748  * If workstdout is set, copy result to stdout.
 749  * All unlinking of initialfile, rev2, and rev3 should be done by tempunlink().
 750  */
 751 {
 752         struct buf commarg;
 753         struct buf subs;
 754         char const *rev2, *rev3;
 755         int i;
 756         char const *cov[10], *mergev[11];
 757         char const **p;
 758
 759         bufautobegin(&commarg);
 760         bufautobegin(&subs);
 761         rev2 = maketemp(0);
 762         rev3 = maketemp(3); /* buildrevision() may use 1 and 2 */
 763
 764         cov[1] = CO;
 765         /* cov[2] setup below */
 766         p = &cov[3];
 767         if (expandarg) *p++ = expandarg;
 768         if (suffixarg) *p++ = suffixarg;
 769         if (versionarg) *p++ = versionarg;
 770         if (zonearg) *p++ = zonearg;
 771         *p++ = quietarg;
 772         *p++ = RCSname;
 773         *p = 0;
 774
 775         mergev[1] = MERGE;
 776         mergev[2] = mergev[4] = "-L";
 777         /* rest of mergev setup below */
 778
 779         i=0;
 780         while (i<lastjoin) {
 781                 /*prepare marker for merge*/
 782                 if (i==0)
 783                         bufscpy(&subs, targetdelta->num);
 784                 else {
 785                         bufscat(&subs, ",");
 786                         bufscat(&subs, joinlist[i-2]);
 787                         bufscat(&subs, ":");
 788                         bufscat(&subs, joinlist[i-1]);
 789                 }
 790                 diagnose("revision %s\n",joinlist[i]);
 791                 bufscpy(&commarg, "-p");
 792                 bufscat(&commarg, joinlist[i]);
 793                 cov[2] = commarg.string;
 794                 if (runv(-1, rev2, cov))
 795                         goto badmerge;
 796                 diagnose("revision %s\n",joinlist[i+1]);
 797                 bufscpy(&commarg, "-p");
 798                 bufscat(&commarg, joinlist[i+1]);
 799                 cov[2] = commarg.string;
 800                 if (runv(-1, rev3, cov))
 801                         goto badmerge;
 802                 diagnose("merging...\n");
 803                 mergev[3] = subs.string;
 804                 mergev[5] = joinlist[i+1];
 805                 p = &mergev[6];
 806                 if (quietflag) *p++ = quietarg;
 807                 if (lastjoin<=i+2 && workstdout) *p++ = "-p";
 808                 *p++ = initialfile;
 809                 *p++ = rev2;
 810                 *p++ = rev3;
 811                 *p = 0;
 812                 switch (runv(-1, (char*)0, mergev)) {
 813                     case DIFF_FAILURE: case DIFF_SUCCESS:
 814                         break;
 815                     default:
 816                         goto badmerge;
 817                 }
 818                 i=i+2;
 819         }
 820         bufautoend(&commarg);
 821         bufautoend(&subs);
 822         return true;
 823
 824     badmerge:
 825         nerror++;
 826         bufautoend(&commarg);
 827         bufautoend(&subs);
 828         return false;
 829 }