usr.bin/patch/patch.c

   1 /*-
   2  * Copyright 1986, Larry Wall
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following condition is met:
   6  * 1. Redistributions of source code must retain the above copyright notice,
   7  * this condition and the following disclaimer.
   8  *
   9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  10  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  11  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  12  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  13  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  14  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  15  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  16  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  17  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  18  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  19  * SUCH DAMAGE.
  20  *
  21  * patch - a program to apply diffs to original files
  22  *
  23  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  24  * behaviour
  25  *
  26  * $OpenBSD: patch.c,v 1.50 2012/05/15 19:32:02 millert Exp $
  27  * $FreeBSD$
  28  *
  29  */
  30
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33
  34 #include <ctype.h>
  35 #include <getopt.h>
  36 #include <limits.h>
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41
  42 #include "common.h"
  43 #include "util.h"
  44 #include "pch.h"
  45 #include "inp.h"
  46 #include "backupfile.h"
  47 #include "pathnames.h"
  48
  49 mode_t          filemode = 0644;
  50
  51 char            *buf;                   /* general purpose buffer */
  52 size_t          buf_size;               /* size of the general purpose buffer */
  53
  54 bool            using_plan_a = true;    /* try to keep everything in memory */
  55 bool            out_of_mem = false;     /* ran out of memory in plan a */
  56
  57 #define MAXFILEC 2
  58
  59 char            *filearg[MAXFILEC];
  60 bool            ok_to_create_file = false;
  61 char            *outname = NULL;
  62 char            *origprae = NULL;
  63 char            *TMPOUTNAME;
  64 char            *TMPINNAME;
  65 char            *TMPREJNAME;
  66 char            *TMPPATNAME;
  67 bool            toutkeep = false;
  68 bool            trejkeep = false;
  69 bool            warn_on_invalid_line;
  70 bool            last_line_missing_eol;
  71
  72 #ifdef DEBUGGING
  73 int             debug = 0;
  74 #endif
  75
  76 bool            force = false;
  77 bool            batch = false;
  78 bool            verbose = true;
  79 bool            reverse = false;
  80 bool            noreverse = false;
  81 bool            skip_rest_of_patch = false;
  82 int             strippath = 957;
  83 bool            canonicalize = false;
  84 bool            check_only = false;
  85 int             diff_type = 0;
  86 char            *revision = NULL;       /* prerequisite revision, if any */
  87 LINENUM         input_lines = 0;        /* how long is input file in lines */
  88 int             posix = 0;              /* strict POSIX mode? */
  89
  90 static void     reinitialize_almost_everything(void);
  91 static void     get_some_switches(void);
  92 static LINENUM  locate_hunk(LINENUM);
  93 static void     abort_context_hunk(void);
  94 static void     rej_line(int, LINENUM);
  95 static void     abort_hunk(void);
  96 static void     apply_hunk(LINENUM);
  97 static void     init_output(const char *);
  98 static void     init_reject(const char *);
  99 static void     copy_till(LINENUM, bool);
 100 static bool     spew_output(void);
 101 static void     dump_line(LINENUM, bool);
 102 static bool     patch_match(LINENUM, LINENUM, LINENUM);
 103 static bool     similar(const char *, const char *, int);
 104 static void     usage(void);
 105
 106 /* true if -E was specified on command line.  */
 107 static bool     remove_empty_files = false;
 108
 109 /* true if -R was specified on command line.  */
 110 static bool     reverse_flag_specified = false;
 111
 112 /* buffer holding the name of the rejected patch file. */
 113 static char     rejname[NAME_MAX + 1];
 114
 115 /* how many input lines have been irretractibly output */
 116 static LINENUM  last_frozen_line = 0;
 117
 118 static int      Argc;           /* guess */
 119 static char     **Argv;
 120 static int      Argc_last;      /* for restarting plan_b */
 121 static char     **Argv_last;
 122
 123 static FILE     *ofp = NULL;    /* output file pointer */
 124 static FILE     *rejfp = NULL;  /* reject file pointer */
 125
 126 static int      filec = 0;      /* how many file arguments? */
 127 static LINENUM  last_offset = 0;
 128 static LINENUM  maxfuzz = 2;
 129
 130 /* patch using ifdef, ifndef, etc. */
 131 static bool             do_defines = false;
 132 /* #ifdef xyzzy */
 133 static char             if_defined[128];
 134 /* #ifndef xyzzy */
 135 static char             not_defined[128];
 136 /* #else */
 137 static const char       else_defined[] = "#else\n";
 138 /* #endif xyzzy */
 139 static char             end_defined[128];
 140
 141
 142 /* Apply a set of diffs as appropriate. */
 143
 144 int
 145 main(int argc, char *argv[])
 146 {
 147         int     error = 0, hunk, failed, i, fd;
 148         bool    patch_seen;
 149         LINENUM where = 0, newwhere, fuzz, mymaxfuzz;
 150         const   char *tmpdir;
 151         char    *v;
 152
 153         setlinebuf(stdout);
 154         setlinebuf(stderr);
 155         for (i = 0; i < MAXFILEC; i++)
 156                 filearg[i] = NULL;
 157
 158         buf_size = INITLINELEN;
 159         buf = malloc((unsigned)(buf_size));
 160         if (buf == NULL)
 161                 fatal("out of memory\n");
 162
 163         /* Cons up the names of the temporary files.  */
 164         if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
 165                 tmpdir = _PATH_TMP;
 166         for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
 167                 ;
 168         i++;
 169         if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
 170                 fatal("cannot allocate memory");
 171         if ((fd = mkstemp(TMPOUTNAME)) < 0)
 172                 pfatal("can't create %s", TMPOUTNAME);
 173         close(fd);
 174
 175         if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
 176                 fatal("cannot allocate memory");
 177         if ((fd = mkstemp(TMPINNAME)) < 0)
 178                 pfatal("can't create %s", TMPINNAME);
 179         close(fd);
 180
 181         if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
 182                 fatal("cannot allocate memory");
 183         if ((fd = mkstemp(TMPREJNAME)) < 0)
 184                 pfatal("can't create %s", TMPREJNAME);
 185         close(fd);
 186
 187         if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
 188                 fatal("cannot allocate memory");
 189         if ((fd = mkstemp(TMPPATNAME)) < 0)
 190                 pfatal("can't create %s", TMPPATNAME);
 191         close(fd);
 192
 193         v = getenv("SIMPLE_BACKUP_SUFFIX");
 194         if (v)
 195                 simple_backup_suffix = v;
 196         else
 197                 simple_backup_suffix = ORIGEXT;
 198
 199         /* parse switches */
 200         Argc = argc;
 201         Argv = argv;
 202         get_some_switches();
 203
 204         if (backup_type == none) {
 205                 if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
 206                         v = getenv("VERSION_CONTROL");
 207                 if (v != NULL || !posix)
 208                         backup_type = get_version(v);   /* OK to pass NULL. */
 209         }
 210
 211         /* make sure we clean up /tmp in case of disaster */
 212         set_signals(0);
 213
 214         patch_seen = false;
 215         for (open_patch_file(filearg[1]); there_is_another_patch();
 216             reinitialize_almost_everything()) {
 217                 /* for each patch in patch file */
 218
 219                 patch_seen = true;
 220
 221                 warn_on_invalid_line = true;
 222
 223                 if (outname == NULL)
 224                         outname = savestr(filearg[0]);
 225
 226                 /* for ed script just up and do it and exit */
 227                 if (diff_type == ED_DIFF) {
 228                         do_ed_script();
 229                         continue;
 230                 }
 231                 /* initialize the patched file */
 232                 if (!skip_rest_of_patch)
 233                         init_output(TMPOUTNAME);
 234
 235                 /* initialize reject file */
 236                 init_reject(TMPREJNAME);
 237
 238                 /* find out where all the lines are */
 239                 if (!skip_rest_of_patch)
 240                         scan_input(filearg[0]);
 241
 242                 /*
 243                  * from here on, open no standard i/o files, because
 244                  * malloc might misfire and we can't catch it easily
 245                  */
 246
 247                 /* apply each hunk of patch */
 248                 hunk = 0;
 249                 failed = 0;
 250                 out_of_mem = false;
 251                 while (another_hunk()) {
 252                         hunk++;
 253                         fuzz = 0;
 254                         mymaxfuzz = pch_context();
 255                         if (maxfuzz < mymaxfuzz)
 256                                 mymaxfuzz = maxfuzz;
 257                         if (!skip_rest_of_patch) {
 258                                 do {
 259                                         where = locate_hunk(fuzz);
 260                                         if (hunk == 1 && where == 0 && !force) {
 261                                                 /* dwim for reversed patch? */
 262                                                 if (!pch_swap()) {
 263                                                         if (fuzz == 0)
 264                                                                 say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
 265                                                         continue;
 266                                                 }
 267                                                 reverse = !reverse;
 268                                                 /* try again */
 269                                                 where = locate_hunk(fuzz);
 270                                                 if (where == 0) {
 271                                                         /* didn't find it swapped */
 272                                                         if (!pch_swap())
 273                                                                 /* put it back to normal */
 274                                                                 fatal("lost hunk on alloc error!\n");
 275                                                         reverse = !reverse;
 276                                                 } else if (noreverse) {
 277                                                         if (!pch_swap())
 278                                                                 /* put it back to normal */
 279                                                                 fatal("lost hunk on alloc error!\n");
 280                                                         reverse = !reverse;
 281                                                         say("Ignoring previously applied (or reversed) patch.\n");
 282                                                         skip_rest_of_patch = true;
 283                                                 } else if (batch) {
 284                                                         if (verbose)
 285                                                                 say("%seversed (or previously applied) patch detected!  %s -R.",
 286                                                                     reverse ? "R" : "Unr",
 287                                                                     reverse ? "Assuming" : "Ignoring");
 288                                                 } else {
 289                                                         ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
 290                                                             reverse ? "R" : "Unr",
 291                                                             reverse ? "Assume" : "Ignore");
 292                                                         if (*buf == 'n') {
 293                                                                 ask("Apply anyway? [n] ");
 294                                                                 if (*buf != 'y')
 295                                                                         skip_rest_of_patch = true;
 296                                                                 where = 0;
 297                                                                 reverse = !reverse;
 298                                                                 if (!pch_swap())
 299                                                                         /* put it back to normal */
 300                                                                         fatal("lost hunk on alloc error!\n");
 301                                                         }
 302                                                 }
 303                                         }
 304                                 } while (!skip_rest_of_patch && where == 0 &&
 305                                     ++fuzz <= mymaxfuzz);
 306
 307                                 if (skip_rest_of_patch) {       /* just got decided */
 308                                         if (ferror(ofp) || fclose(ofp)) {
 309                                                 say("Error writing %s\n",
 310                                                     TMPOUTNAME);
 311                                                 error = 1;
 312                                         }
 313                                         ofp = NULL;
 314                                 }
 315                         }
 316                         newwhere = pch_newfirst() + last_offset;
 317                         if (skip_rest_of_patch) {
 318                                 abort_hunk();
 319                                 failed++;
 320                                 if (verbose)
 321                                         say("Hunk #%d ignored at %ld.\n",
 322                                             hunk, newwhere);
 323                         } else if (where == 0) {
 324                                 abort_hunk();
 325                                 failed++;
 326                                 if (verbose)
 327                                         say("Hunk #%d failed at %ld.\n",
 328                                             hunk, newwhere);
 329                         } else {
 330                                 apply_hunk(where);
 331                                 if (verbose) {
 332                                         say("Hunk #%d succeeded at %ld",
 333                                             hunk, newwhere);
 334                                         if (fuzz != 0)
 335                                                 say(" with fuzz %ld", fuzz);
 336                                         if (last_offset)
 337                                                 say(" (offset %ld line%s)",
 338                                                     last_offset,
 339                                                     last_offset == 1L ? "" : "s");
 340                                         say(".\n");
 341                                 }
 342                         }
 343                 }
 344
 345                 if (out_of_mem && using_plan_a) {
 346                         Argc = Argc_last;
 347                         Argv = Argv_last;
 348                         say("\n\nRan out of memory using Plan A--trying again...\n\n");
 349                         if (ofp)
 350                                 fclose(ofp);
 351                         ofp = NULL;
 352                         if (rejfp)
 353                                 fclose(rejfp);
 354                         rejfp = NULL;
 355                         continue;
 356                 }
 357                 if (hunk == 0)
 358                         fatal("Internal error: hunk should not be 0\n");
 359
 360                 /* finish spewing out the new file */
 361                 if (!skip_rest_of_patch && !spew_output()) {
 362                         say("Can't write %s\n", TMPOUTNAME);
 363                         error = 1;
 364                 }
 365
 366                 /* and put the output where desired */
 367                 ignore_signals();
 368                 if (!skip_rest_of_patch) {
 369                         struct stat     statbuf;
 370                         char    *realout = outname;
 371
 372                         if (!check_only) {
 373                                 if (move_file(TMPOUTNAME, outname) < 0) {
 374                                         toutkeep = true;
 375                                         realout = TMPOUTNAME;
 376                                         chmod(TMPOUTNAME, filemode);
 377                                 } else
 378                                         chmod(outname, filemode);
 379
 380                                 if (remove_empty_files &&
 381                                     stat(realout, &statbuf) == 0 &&
 382                                     statbuf.st_size == 0) {
 383                                         if (verbose)
 384                                                 say("Removing %s (empty after patching).\n",
 385                                                     realout);
 386                                         unlink(realout);
 387                                 }
 388                         }
 389                 }
 390                 if (ferror(rejfp) || fclose(rejfp)) {
 391                         say("Error writing %s\n", rejname);
 392                         error = 1;
 393                 }
 394                 rejfp = NULL;
 395                 if (failed) {
 396                         error = 1;
 397                         if (*rejname == '\0') {
 398                                 if (strlcpy(rejname, outname,
 399                                     sizeof(rejname)) >= sizeof(rejname))
 400                                         fatal("filename %s is too long\n", outname);
 401                                 if (strlcat(rejname, REJEXT,
 402                                     sizeof(rejname)) >= sizeof(rejname))
 403                                         fatal("filename %s is too long\n", outname);
 404                         }
 405                         if (!check_only)
 406                                 say("%d out of %d hunks %s--saving rejects to %s\n",
 407                                     failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
 408                         else
 409                                 say("%d out of %d hunks %s\n",
 410                                     failed, hunk, skip_rest_of_patch ? "ignored" : "failed");
 411                         if (!check_only && move_file(TMPREJNAME, rejname) < 0)
 412                                 trejkeep = true;
 413                 }
 414                 set_signals(1);
 415         }
 416
 417         if (!patch_seen)
 418                 error = 2;
 419
 420         my_exit(error);
 421         /* NOTREACHED */
 422 }
 423
 424 /* Prepare to find the next patch to do in the patch file. */
 425
 426 static void
 427 reinitialize_almost_everything(void)
 428 {
 429         re_patch();
 430         re_input();
 431
 432         input_lines = 0;
 433         last_frozen_line = 0;
 434
 435         filec = 0;
 436         if (!out_of_mem) {
 437                 free(filearg[0]);
 438                 filearg[0] = NULL;
 439         }
 440
 441         free(outname);
 442         outname = NULL;
 443
 444         last_offset = 0;
 445         diff_type = 0;
 446
 447         free(revision);
 448         revision = NULL;
 449
 450         reverse = reverse_flag_specified;
 451         skip_rest_of_patch = false;
 452
 453         get_some_switches();
 454 }
 455
 456 /* Process switches and filenames. */
 457
 458 static void
 459 get_some_switches(void)
 460 {
 461         const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
 462         static struct option longopts[] = {
 463                 {"backup",              no_argument,            0,      'b'},
 464                 {"batch",               no_argument,            0,      't'},
 465                 {"check",               no_argument,            0,      'C'},
 466                 {"context",             no_argument,            0,      'c'},
 467                 {"debug",               required_argument,      0,      'x'},
 468                 {"directory",           required_argument,      0,      'd'},
 469                 {"ed",                  no_argument,            0,      'e'},
 470                 {"force",               no_argument,            0,      'f'},
 471                 {"forward",             no_argument,            0,      'N'},
 472                 {"fuzz",                required_argument,      0,      'F'},
 473                 {"ifdef",               required_argument,      0,      'D'},
 474                 {"input",               required_argument,      0,      'i'},
 475                 {"ignore-whitespace",   no_argument,            0,      'l'},
 476                 {"normal",              no_argument,            0,      'n'},
 477                 {"output",              required_argument,      0,      'o'},
 478                 {"prefix",              required_argument,      0,      'B'},
 479                 {"quiet",               no_argument,            0,      's'},
 480                 {"reject-file",         required_argument,      0,      'r'},
 481                 {"remove-empty-files",  no_argument,            0,      'E'},
 482                 {"reverse",             no_argument,            0,      'R'},
 483                 {"silent",              no_argument,            0,      's'},
 484                 {"strip",               required_argument,      0,      'p'},
 485                 {"suffix",              required_argument,      0,      'z'},
 486                 {"unified",             no_argument,            0,      'u'},
 487                 {"version",             no_argument,            0,      'v'},
 488                 {"version-control",     required_argument,      0,      'V'},
 489                 {"posix",               no_argument,            &posix, 1},
 490                 {NULL,                  0,                      0,      0}
 491         };
 492         int ch;
 493
 494         rejname[0] = '\0';
 495         Argc_last = Argc;
 496         Argv_last = Argv;
 497         if (!Argc)
 498                 return;
 499         optreset = optind = 1;
 500         while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
 501                 switch (ch) {
 502                 case 'b':
 503                         if (backup_type == none)
 504                                 backup_type = numbered_existing;
 505                         if (optarg == NULL)
 506                                 break;
 507                         if (verbose)
 508                                 say("Warning, the ``-b suffix'' option has been"
 509                                     " obsoleted by the -z option.\n");
 510                         /* FALLTHROUGH */
 511                 case 'z':
 512                         /* must directly follow 'b' case for backwards compat */
 513                         simple_backup_suffix = savestr(optarg);
 514                         break;
 515                 case 'B':
 516                         origprae = savestr(optarg);
 517                         break;
 518                 case 'c':
 519                         diff_type = CONTEXT_DIFF;
 520                         break;
 521                 case 'C':
 522                         check_only = true;
 523                         break;
 524                 case 'd':
 525                         if (chdir(optarg) < 0)
 526                                 pfatal("can't cd to %s", optarg);
 527                         break;
 528                 case 'D':
 529                         do_defines = true;
 530                         if (!isalpha((unsigned char)*optarg) && *optarg != '_')
 531                                 fatal("argument to -D is not an identifier\n");
 532                         snprintf(if_defined, sizeof if_defined,
 533                             "#ifdef %s\n", optarg);
 534                         snprintf(not_defined, sizeof not_defined,
 535                             "#ifndef %s\n", optarg);
 536                         snprintf(end_defined, sizeof end_defined,
 537                             "#endif /* %s */\n", optarg);
 538                         break;
 539                 case 'e':
 540                         diff_type = ED_DIFF;
 541                         break;
 542                 case 'E':
 543                         remove_empty_files = true;
 544                         break;
 545                 case 'f':
 546                         force = true;
 547                         break;
 548                 case 'F':
 549                         maxfuzz = atoi(optarg);
 550                         break;
 551                 case 'i':
 552                         if (++filec == MAXFILEC)
 553                                 fatal("too many file arguments\n");
 554                         filearg[filec] = savestr(optarg);
 555                         break;
 556                 case 'l':
 557                         canonicalize = true;
 558                         break;
 559                 case 'n':
 560                         diff_type = NORMAL_DIFF;
 561                         break;
 562                 case 'N':
 563                         noreverse = true;
 564                         break;
 565                 case 'o':
 566                         outname = savestr(optarg);
 567                         break;
 568                 case 'p':
 569                         strippath = atoi(optarg);
 570                         break;
 571                 case 'r':
 572                         if (strlcpy(rejname, optarg,
 573                             sizeof(rejname)) >= sizeof(rejname))
 574                                 fatal("argument for -r is too long\n");
 575                         break;
 576                 case 'R':
 577                         reverse = true;
 578                         reverse_flag_specified = true;
 579                         break;
 580                 case 's':
 581                         verbose = false;
 582                         break;
 583                 case 't':
 584                         batch = true;
 585                         break;
 586                 case 'u':
 587                         diff_type = UNI_DIFF;
 588                         break;
 589                 case 'v':
 590                         version();
 591                         break;
 592                 case 'V':
 593                         backup_type = get_version(optarg);
 594                         break;
 595 #ifdef DEBUGGING
 596                 case 'x':
 597                         debug = atoi(optarg);
 598                         break;
 599 #endif
 600                 default:
 601                         if (ch != '\0')
 602                                 usage();
 603                         break;
 604                 }
 605         }
 606         Argc -= optind;
 607         Argv += optind;
 608
 609         if (Argc > 0) {
 610                 filearg[0] = savestr(*Argv++);
 611                 Argc--;
 612                 while (Argc > 0) {
 613                         if (++filec == MAXFILEC)
 614                                 fatal("too many file arguments\n");
 615                         filearg[filec] = savestr(*Argv++);
 616                         Argc--;
 617                 }
 618         }
 619
 620         if (getenv("POSIXLY_CORRECT") != NULL)
 621                 posix = 1;
 622 }
 623
 624 static void
 625 usage(void)
 626 {
 627         fprintf(stderr,
 628 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
 629 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
 630 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
 631 "             [--posix] [origfile [patchfile]]\n"
 632 "       patch <patchfile\n");
 633         my_exit(EXIT_SUCCESS);
 634 }
 635
 636 /*
 637  * Attempt to find the right place to apply this hunk of patch.
 638  */
 639 static LINENUM
 640 locate_hunk(LINENUM fuzz)
 641 {
 642         LINENUM first_guess = pch_first() + last_offset;
 643         LINENUM offset;
 644         LINENUM pat_lines = pch_ptrn_lines();
 645         LINENUM max_pos_offset = input_lines - first_guess - pat_lines + 1;
 646         LINENUM max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
 647
 648         if (pat_lines == 0) {           /* null range matches always */
 649                 if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
 650                     || diff_type == NEW_CONTEXT_DIFF
 651                     || diff_type == UNI_DIFF)) {
 652                         say("Empty context always matches.\n");
 653                 }
 654                 return (first_guess);
 655         }
 656         if (max_neg_offset >= first_guess)      /* do not try lines < 0 */
 657                 max_neg_offset = first_guess - 1;
 658         if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
 659                 return first_guess;
 660         for (offset = 1; ; offset++) {
 661                 bool    check_after = (offset <= max_pos_offset);
 662                 bool    check_before = (offset <= max_neg_offset);
 663
 664                 if (check_after && patch_match(first_guess, offset, fuzz)) {
 665 #ifdef DEBUGGING
 666                         if (debug & 1)
 667                                 say("Offset changing from %ld to %ld\n",
 668                                     last_offset, offset);
 669 #endif
 670                         last_offset = offset;
 671                         return first_guess + offset;
 672                 } else if (check_before && patch_match(first_guess, -offset, fuzz)) {
 673 #ifdef DEBUGGING
 674                         if (debug & 1)
 675                                 say("Offset changing from %ld to %ld\n",
 676                                     last_offset, -offset);
 677 #endif
 678                         last_offset = -offset;
 679                         return first_guess - offset;
 680                 } else if (!check_before && !check_after)
 681                         return 0;
 682         }
 683 }
 684
 685 /* We did not find the pattern, dump out the hunk so they can handle it. */
 686
 687 static void
 688 abort_context_hunk(void)
 689 {
 690         LINENUM i;
 691         const LINENUM   pat_end = pch_end();
 692         /*
 693          * add in last_offset to guess the same as the previous successful
 694          * hunk
 695          */
 696         const LINENUM   oldfirst = pch_first() + last_offset;
 697         const LINENUM   newfirst = pch_newfirst() + last_offset;
 698         const LINENUM   oldlast = oldfirst + pch_ptrn_lines() - 1;
 699         const LINENUM   newlast = newfirst + pch_repl_lines() - 1;
 700         const char      *stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
 701         const char      *minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
 702
 703         fprintf(rejfp, "***************\n");
 704         for (i = 0; i <= pat_end; i++) {
 705                 switch (pch_char(i)) {
 706                 case '*':
 707                         if (oldlast < oldfirst)
 708                                 fprintf(rejfp, "*** 0%s\n", stars);
 709                         else if (oldlast == oldfirst)
 710                                 fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
 711                         else
 712                                 fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
 713                                     oldlast, stars);
 714                         break;
 715                 case '=':
 716                         if (newlast < newfirst)
 717                                 fprintf(rejfp, "--- 0%s\n", minuses);
 718                         else if (newlast == newfirst)
 719                                 fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
 720                         else
 721                                 fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
 722                                     newlast, minuses);
 723                         break;
 724                 case '\n':
 725                         fprintf(rejfp, "%s", pfetch(i));
 726                         break;
 727                 case ' ':
 728                 case '-':
 729                 case '+':
 730                 case '!':
 731                         fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
 732                         break;
 733                 default:
 734                         fatal("fatal internal error in abort_context_hunk\n");
 735                 }
 736         }
 737 }
 738
 739 static void
 740 rej_line(int ch, LINENUM i)
 741 {
 742         size_t len;
 743         const char *line = pfetch(i);
 744
 745         len = strlen(line);
 746
 747         fprintf(rejfp, "%c%s", ch, line);
 748         if (len == 0 || line[len-1] != '\n')
 749                 fprintf(rejfp, "\n\\ No newline at end of file\n");
 750 }
 751
 752 static void
 753 abort_hunk(void)
 754 {
 755         LINENUM         i, j, split;
 756         int             ch1, ch2;
 757         const LINENUM   pat_end = pch_end();
 758         const LINENUM   oldfirst = pch_first() + last_offset;
 759         const LINENUM   newfirst = pch_newfirst() + last_offset;
 760
 761         if (diff_type != UNI_DIFF) {
 762                 abort_context_hunk();
 763                 return;
 764         }
 765         split = -1;
 766         for (i = 0; i <= pat_end; i++) {
 767                 if (pch_char(i) == '=') {
 768                         split = i;
 769                         break;
 770                 }
 771         }
 772         if (split == -1) {
 773                 fprintf(rejfp, "malformed hunk: no split found\n");
 774                 return;
 775         }
 776         i = 0;
 777         j = split + 1;
 778         fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
 779             pch_ptrn_lines() ? oldfirst : 0,
 780             pch_ptrn_lines(), newfirst, pch_repl_lines());
 781         while (i < split || j <= pat_end) {
 782                 ch1 = i < split ? pch_char(i) : -1;
 783                 ch2 = j <= pat_end ? pch_char(j) : -1;
 784                 if (ch1 == '-') {
 785                         rej_line('-', i);
 786                         i++;
 787                 } else if (ch1 == ' ' && ch2 == ' ') {
 788                         rej_line(' ', i);
 789                         i++;
 790                         j++;
 791                 } else if (ch1 == '!' && ch2 == '!') {
 792                         while (i < split && ch1 == '!') {
 793                                 rej_line('-', i);
 794                                 i++;
 795                                 ch1 = i < split ? pch_char(i) : -1;
 796                         }
 797                         while (j <= pat_end && ch2 == '!') {
 798                                 rej_line('+', j);
 799                                 j++;
 800                                 ch2 = j <= pat_end ? pch_char(j) : -1;
 801                         }
 802                 } else if (ch1 == '*') {
 803                         i++;
 804                 } else if (ch2 == '+' || ch2 == ' ') {
 805                         rej_line(ch2, j);
 806                         j++;
 807                 } else {
 808                         fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
 809                             i, split, j);
 810                         rej_line(ch1, i);
 811                         rej_line(ch2, j);
 812                         return;
 813                 }
 814         }
 815 }
 816
 817 /* We found where to apply it (we hope), so do it. */
 818
 819 static void
 820 apply_hunk(LINENUM where)
 821 {
 822         LINENUM         old = 1;
 823         const LINENUM   lastline = pch_ptrn_lines();
 824         LINENUM         new = lastline + 1;
 825 #define OUTSIDE 0
 826 #define IN_IFNDEF 1
 827 #define IN_IFDEF 2
 828 #define IN_ELSE 3
 829         int             def_state = OUTSIDE;
 830         const LINENUM   pat_end = pch_end();
 831
 832         where--;
 833         while (pch_char(new) == '=' || pch_char(new) == '\n')
 834                 new++;
 835
 836         while (old <= lastline) {
 837                 if (pch_char(old) == '-') {
 838                         copy_till(where + old - 1, false);
 839                         if (do_defines) {
 840                                 if (def_state == OUTSIDE) {
 841                                         fputs(not_defined, ofp);
 842                                         def_state = IN_IFNDEF;
 843                                 } else if (def_state == IN_IFDEF) {
 844                                         fputs(else_defined, ofp);
 845                                         def_state = IN_ELSE;
 846                                 }
 847                                 fputs(pfetch(old), ofp);
 848                         }
 849                         last_frozen_line++;
 850                         old++;
 851                 } else if (new > pat_end) {
 852                         break;
 853                 } else if (pch_char(new) == '+') {
 854                         copy_till(where + old - 1, false);
 855                         if (do_defines) {
 856                                 if (def_state == IN_IFNDEF) {
 857                                         fputs(else_defined, ofp);
 858                                         def_state = IN_ELSE;
 859                                 } else if (def_state == OUTSIDE) {
 860                                         fputs(if_defined, ofp);
 861                                         def_state = IN_IFDEF;
 862                                 }
 863                         }
 864                         fputs(pfetch(new), ofp);
 865                         new++;
 866                 } else if (pch_char(new) != pch_char(old)) {
 867                         say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
 868                             pch_hunk_beg() + old,
 869                             pch_hunk_beg() + new);
 870 #ifdef DEBUGGING
 871                         say("oldchar = '%c', newchar = '%c'\n",
 872                             pch_char(old), pch_char(new));
 873 #endif
 874                         my_exit(2);
 875                 } else if (pch_char(new) == '!') {
 876                         copy_till(where + old - 1, false);
 877                         if (do_defines) {
 878                                 fputs(not_defined, ofp);
 879                                 def_state = IN_IFNDEF;
 880                         }
 881                         while (pch_char(old) == '!') {
 882                                 if (do_defines) {
 883                                         fputs(pfetch(old), ofp);
 884                                 }
 885                                 last_frozen_line++;
 886                                 old++;
 887                         }
 888                         if (do_defines) {
 889                                 fputs(else_defined, ofp);
 890                                 def_state = IN_ELSE;
 891                         }
 892                         while (pch_char(new) == '!') {
 893                                 fputs(pfetch(new), ofp);
 894                                 new++;
 895                         }
 896                 } else {
 897                         if (pch_char(new) != ' ')
 898                                 fatal("Internal error: expected ' '\n");
 899                         old++;
 900                         new++;
 901                         if (do_defines && def_state != OUTSIDE) {
 902                                 fputs(end_defined, ofp);
 903                                 def_state = OUTSIDE;
 904                         }
 905                 }
 906         }
 907         if (new <= pat_end && pch_char(new) == '+') {
 908                 copy_till(where + old - 1, false);
 909                 if (do_defines) {
 910                         if (def_state == OUTSIDE) {
 911                                 fputs(if_defined, ofp);
 912                                 def_state = IN_IFDEF;
 913                         } else if (def_state == IN_IFNDEF) {
 914                                 fputs(else_defined, ofp);
 915                                 def_state = IN_ELSE;
 916                         }
 917                 }
 918                 while (new <= pat_end && pch_char(new) == '+') {
 919                         fputs(pfetch(new), ofp);
 920                         new++;
 921                 }
 922         }
 923         if (do_defines && def_state != OUTSIDE) {
 924                 fputs(end_defined, ofp);
 925         }
 926 }
 927
 928 /*
 929  * Open the new file.
 930  */
 931 static void
 932 init_output(const char *name)
 933 {
 934         ofp = fopen(name, "w");
 935         if (ofp == NULL)
 936                 pfatal("can't create %s", name);
 937 }
 938
 939 /*
 940  * Open a file to put hunks we can't locate.
 941  */
 942 static void
 943 init_reject(const char *name)
 944 {
 945         rejfp = fopen(name, "w");
 946         if (rejfp == NULL)
 947                 pfatal("can't create %s", name);
 948 }
 949
 950 /*
 951  * Copy input file to output, up to wherever hunk is to be applied.
 952  * If endoffile is true, treat the last line specially since it may
 953  * lack a newline.
 954  */
 955 static void
 956 copy_till(LINENUM lastline, bool endoffile)
 957 {
 958         if (last_frozen_line > lastline)
 959                 fatal("misordered hunks! output would be garbled\n");
 960         while (last_frozen_line < lastline) {
 961                 if (++last_frozen_line == lastline && endoffile)
 962                         dump_line(last_frozen_line, !last_line_missing_eol);
 963                 else
 964                         dump_line(last_frozen_line, true);
 965         }
 966 }
 967
 968 /*
 969  * Finish copying the input file to the output file.
 970  */
 971 static bool
 972 spew_output(void)
 973 {
 974         int rv;
 975
 976 #ifdef DEBUGGING
 977         if (debug & 256)
 978                 say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
 979 #endif
 980         if (input_lines)
 981                 copy_till(input_lines, true);   /* dump remainder of file */
 982         rv = ferror(ofp) == 0 && fclose(ofp) == 0;
 983         ofp = NULL;
 984         return rv;
 985 }
 986
 987 /*
 988  * Copy one line from input to output.
 989  */
 990 static void
 991 dump_line(LINENUM line, bool write_newline)
 992 {
 993         char    *s;
 994
 995         s = ifetch(line, 0);
 996         if (s == NULL)
 997                 return;
 998         /* Note: string is not NUL terminated. */
 999         for (; *s != '\n'; s++)
1000                 putc(*s, ofp);
1001         if (write_newline)
1002                 putc('\n', ofp);
1003 }
1004
1005 /*
1006  * Does the patch pattern match at line base+offset?
1007  */
1008 static bool
1009 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1010 {
1011         LINENUM         pline = 1 + fuzz;
1012         LINENUM         iline;
1013         LINENUM         pat_lines = pch_ptrn_lines() - fuzz;
1014         const char      *ilineptr;
1015         const char      *plineptr;
1016         short           plinelen;
1017
1018         for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1019                 ilineptr = ifetch(iline, offset >= 0);
1020                 if (ilineptr == NULL)
1021                         return false;
1022                 plineptr = pfetch(pline);
1023                 plinelen = pch_line_len(pline);
1024                 if (canonicalize) {
1025                         if (!similar(ilineptr, plineptr, plinelen))
1026                                 return false;
1027                 } else if (strnNE(ilineptr, plineptr, plinelen))
1028                         return false;
1029                 if (iline == input_lines) {
1030                         /*
1031                          * We are looking at the last line of the file.
1032                          * If the file has no eol, the patch line should
1033                          * not have one either and vice-versa. Note that
1034                          * plinelen > 0.
1035                          */
1036                         if (last_line_missing_eol) {
1037                                 if (plineptr[plinelen - 1] == '\n')
1038                                         return false;
1039                         } else {
1040                                 if (plineptr[plinelen - 1] != '\n')
1041                                         return false;
1042                         }
1043                 }
1044         }
1045         return true;
1046 }
1047
1048 /*
1049  * Do two lines match with canonicalized white space?
1050  */
1051 static bool
1052 similar(const char *a, const char *b, int len)
1053 {
1054         while (len) {
1055                 if (isspace((unsigned char)*b)) {       /* whitespace (or \n) to match? */
1056                         if (!isspace((unsigned char)*a))        /* no corresponding whitespace? */
1057                                 return false;
1058                         while (len && isspace((unsigned char)*b) && *b != '\n')
1059                                 b++, len--;     /* skip pattern whitespace */
1060                         while (isspace((unsigned char)*a) && *a != '\n')
1061                                 a++;    /* skip target whitespace */
1062                         if (*a == '\n' || *b == '\n')
1063                                 return (*a == *b);      /* should end in sync */
1064                 } else if (*a++ != *b++)        /* match non-whitespace chars */
1065                         return false;
1066                 else
1067                         len--;  /* probably not necessary */
1068         }
1069         return true;            /* actually, this is not reached */
1070         /* since there is always a \n */
1071 }