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 1.54 2014/12/13 10:31:07 tobias 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 static bool     Vflag = false;
 113
 114 /* buffer holding the name of the rejected patch file. */
 115 static char     rejname[PATH_MAX];
 116
 117 /* how many input lines have been irretractibly output */
 118 static LINENUM  last_frozen_line = 0;
 119
 120 static int      Argc;           /* guess */
 121 static char     **Argv;
 122 static int      Argc_last;      /* for restarting plan_b */
 123 static char     **Argv_last;
 124
 125 static FILE     *ofp = NULL;    /* output file pointer */
 126 static FILE     *rejfp = NULL;  /* reject file pointer */
 127
 128 static int      filec = 0;      /* how many file arguments? */
 129 static LINENUM  last_offset = 0;
 130 static LINENUM  maxfuzz = 2;
 131
 132 /* patch using ifdef, ifndef, etc. */
 133 static bool             do_defines = false;
 134 /* #ifdef xyzzy */
 135 static char             if_defined[128];
 136 /* #ifndef xyzzy */
 137 static char             not_defined[128];
 138 /* #else */
 139 static const char       else_defined[] = "#else\n";
 140 /* #endif xyzzy */
 141 static char             end_defined[128];
 142
 143
 144 /* Apply a set of diffs as appropriate. */
 145
 146 int
 147 main(int argc, char *argv[])
 148 {
 149         int     error = 0, hunk, failed, i, fd;
 150         bool    patch_seen, reverse_seen;
 151         LINENUM where = 0, newwhere, fuzz, mymaxfuzz;
 152         const   char *tmpdir;
 153         char    *v;
 154
 155         setvbuf(stdout, NULL, _IOLBF, 0);
 156         setvbuf(stderr, NULL, _IOLBF, 0);
 157         for (i = 0; i < MAXFILEC; i++)
 158                 filearg[i] = NULL;
 159
 160         buf_size = INITLINELEN;
 161         buf = malloc((unsigned)(buf_size));
 162         if (buf == NULL)
 163                 fatal("out of memory\n");
 164
 165         /* Cons up the names of the temporary files.  */
 166         if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
 167                 tmpdir = _PATH_TMP;
 168         for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
 169                 ;
 170         i++;
 171         if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
 172                 fatal("cannot allocate memory");
 173         if ((fd = mkstemp(TMPOUTNAME)) < 0)
 174                 pfatal("can't create %s", TMPOUTNAME);
 175         close(fd);
 176
 177         if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
 178                 fatal("cannot allocate memory");
 179         if ((fd = mkstemp(TMPINNAME)) < 0)
 180                 pfatal("can't create %s", TMPINNAME);
 181         close(fd);
 182
 183         if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
 184                 fatal("cannot allocate memory");
 185         if ((fd = mkstemp(TMPREJNAME)) < 0)
 186                 pfatal("can't create %s", TMPREJNAME);
 187         close(fd);
 188
 189         if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
 190                 fatal("cannot allocate memory");
 191         if ((fd = mkstemp(TMPPATNAME)) < 0)
 192                 pfatal("can't create %s", TMPPATNAME);
 193         close(fd);
 194
 195         v = getenv("SIMPLE_BACKUP_SUFFIX");
 196         if (v)
 197                 simple_backup_suffix = v;
 198         else
 199                 simple_backup_suffix = ORIGEXT;
 200
 201         /* parse switches */
 202         Argc = argc;
 203         Argv = argv;
 204         get_some_switches();
 205
 206         if (!Vflag) {
 207                 if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
 208                         v = getenv("VERSION_CONTROL");
 209                 if (v != NULL || !posix)
 210                         backup_type = get_version(v);   /* OK to pass NULL. */
 211         }
 212
 213         /* make sure we clean up /tmp in case of disaster */
 214         set_signals(0);
 215
 216         patch_seen = false;
 217         for (open_patch_file(filearg[1]); there_is_another_patch();
 218             reinitialize_almost_everything()) {
 219                 /* for each patch in patch file */
 220
 221                 patch_seen = true;
 222
 223                 warn_on_invalid_line = true;
 224
 225                 if (outname == NULL)
 226                         outname = xstrdup(filearg[0]);
 227
 228                 /* for ed script just up and do it and exit */
 229                 if (diff_type == ED_DIFF) {
 230                         do_ed_script();
 231                         continue;
 232                 }
 233                 /* initialize the patched file */
 234                 if (!skip_rest_of_patch)
 235                         init_output(TMPOUTNAME);
 236
 237                 /* initialize reject file */
 238                 init_reject(TMPREJNAME);
 239
 240                 /* find out where all the lines are */
 241                 if (!skip_rest_of_patch)
 242                         scan_input(filearg[0]);
 243
 244                 /*
 245                  * from here on, open no standard i/o files, because
 246                  * malloc might misfire and we can't catch it easily
 247                  */
 248
 249                 /* apply each hunk of patch */
 250                 hunk = 0;
 251                 failed = 0;
 252                 reverse_seen = false;
 253                 out_of_mem = false;
 254                 while (another_hunk()) {
 255                         hunk++;
 256                         fuzz = 0;
 257                         mymaxfuzz = pch_context();
 258                         if (maxfuzz < mymaxfuzz)
 259                                 mymaxfuzz = maxfuzz;
 260                         if (!skip_rest_of_patch) {
 261                                 do {
 262                                         where = locate_hunk(fuzz);
 263                                         if (hunk == 1 && where == 0 && !force && !reverse_seen) {
 264                                                 /* dwim for reversed patch? */
 265                                                 if (!pch_swap()) {
 266                                                         if (fuzz == 0)
 267                                                                 say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
 268                                                         continue;
 269                                                 }
 270                                                 reverse = !reverse;
 271                                                 /* try again */
 272                                                 where = locate_hunk(fuzz);
 273                                                 if (where == 0) {
 274                                                         /* didn't find it swapped */
 275                                                         if (!pch_swap())
 276                                                                 /* put it back to normal */
 277                                                                 fatal("lost hunk on alloc error!\n");
 278                                                         reverse = !reverse;
 279                                                 } else if (noreverse) {
 280                                                         if (!pch_swap())
 281                                                                 /* put it back to normal */
 282                                                                 fatal("lost hunk on alloc error!\n");
 283                                                         reverse = !reverse;
 284                                                         say("Ignoring previously applied (or reversed) patch.\n");
 285                                                         skip_rest_of_patch = true;
 286                                                 } else if (batch) {
 287                                                         if (verbose)
 288                                                                 say("%seversed (or previously applied) patch detected!  %s -R.",
 289                                                                     reverse ? "R" : "Unr",
 290                                                                     reverse ? "Assuming" : "Ignoring");
 291                                                 } else {
 292                                                         ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
 293                                                             reverse ? "R" : "Unr",
 294                                                             reverse ? "Assume" : "Ignore");
 295                                                         if (*buf == 'n') {
 296                                                                 ask("Apply anyway? [n] ");
 297                                                                 if (*buf != 'y')
 298                                                                         skip_rest_of_patch = true;
 299                                                                 else
 300                                                                         reverse_seen = true;
 301                                                                 where = 0;
 302                                                                 reverse = !reverse;
 303                                                                 if (!pch_swap())
 304                                                                         /* put it back to normal */
 305                                                                         fatal("lost hunk on alloc error!\n");
 306                                                         }
 307                                                 }
 308                                         }
 309                                 } while (!skip_rest_of_patch && where == 0 &&
 310                                     ++fuzz <= mymaxfuzz);
 311
 312                                 if (skip_rest_of_patch) {       /* just got decided */
 313                                         if (ferror(ofp) || fclose(ofp)) {
 314                                                 say("Error writing %s\n",
 315                                                     TMPOUTNAME);
 316                                                 error = 1;
 317                                         }
 318                                         ofp = NULL;
 319                                 }
 320                         }
 321                         newwhere = pch_newfirst() + last_offset;
 322                         if (skip_rest_of_patch) {
 323                                 abort_hunk();
 324                                 failed++;
 325                                 if (verbose)
 326                                         say("Hunk #%d ignored at %ld.\n",
 327                                             hunk, newwhere);
 328                         } else if (where == 0) {
 329                                 abort_hunk();
 330                                 failed++;
 331                                 if (verbose)
 332                                         say("Hunk #%d failed at %ld.\n",
 333                                             hunk, newwhere);
 334                         } else {
 335                                 apply_hunk(where);
 336                                 if (verbose) {
 337                                         say("Hunk #%d succeeded at %ld",
 338                                             hunk, newwhere);
 339                                         if (fuzz != 0)
 340                                                 say(" with fuzz %ld", fuzz);
 341                                         if (last_offset)
 342                                                 say(" (offset %ld line%s)",
 343                                                     last_offset,
 344                                                     last_offset == 1L ? "" : "s");
 345                                         say(".\n");
 346                                 }
 347                         }
 348                 }
 349
 350                 if (out_of_mem && using_plan_a) {
 351                         Argc = Argc_last;
 352                         Argv = Argv_last;
 353                         say("\n\nRan out of memory using Plan A--trying again...\n\n");
 354                         if (ofp)
 355                                 fclose(ofp);
 356                         ofp = NULL;
 357                         if (rejfp)
 358                                 fclose(rejfp);
 359                         rejfp = NULL;
 360                         continue;
 361                 }
 362                 if (hunk == 0)
 363                         fatal("Internal error: hunk should not be 0\n");
 364
 365                 /* finish spewing out the new file */
 366                 if (!skip_rest_of_patch && !spew_output()) {
 367                         say("Can't write %s\n", TMPOUTNAME);
 368                         error = 1;
 369                 }
 370
 371                 /* and put the output where desired */
 372                 ignore_signals();
 373                 if (!skip_rest_of_patch) {
 374                         struct stat     statbuf;
 375                         char    *realout = outname;
 376
 377                         if (!check_only) {
 378                                 if (move_file(TMPOUTNAME, outname) < 0) {
 379                                         toutkeep = true;
 380                                         realout = TMPOUTNAME;
 381                                         chmod(TMPOUTNAME, filemode);
 382                                 } else
 383                                         chmod(outname, filemode);
 384
 385                                 if (remove_empty_files &&
 386                                     stat(realout, &statbuf) == 0 &&
 387                                     statbuf.st_size == 0) {
 388                                         if (verbose)
 389                                                 say("Removing %s (empty after patching).\n",
 390                                                     realout);
 391                                         unlink(realout);
 392                                 }
 393                         }
 394                 }
 395                 if (ferror(rejfp) || fclose(rejfp)) {
 396                         say("Error writing %s\n", rejname);
 397                         error = 1;
 398                 }
 399                 rejfp = NULL;
 400                 if (failed) {
 401                         error = 1;
 402                         if (*rejname == '\0') {
 403                                 if (strlcpy(rejname, outname,
 404                                     sizeof(rejname)) >= sizeof(rejname))
 405                                         fatal("filename %s is too long\n", outname);
 406                                 if (strlcat(rejname, REJEXT,
 407                                     sizeof(rejname)) >= sizeof(rejname))
 408                                         fatal("filename %s is too long\n", outname);
 409                         }
 410                         if (!check_only)
 411                                 say("%d out of %d hunks %s--saving rejects to %s\n",
 412                                     failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
 413                         else
 414                                 say("%d out of %d hunks %s while patching %s\n",
 415                                     failed, hunk, skip_rest_of_patch ? "ignored" : "failed", filearg[0]);
 416                         if (!check_only && move_file(TMPREJNAME, rejname) < 0)
 417                                 trejkeep = true;
 418                 }
 419                 set_signals(1);
 420         }
 421
 422         if (!patch_seen)
 423                 error = 2;
 424
 425         my_exit(error);
 426         /* NOTREACHED */
 427 }
 428
 429 /* Prepare to find the next patch to do in the patch file. */
 430
 431 static void
 432 reinitialize_almost_everything(void)
 433 {
 434         re_patch();
 435         re_input();
 436
 437         input_lines = 0;
 438         last_frozen_line = 0;
 439
 440         filec = 0;
 441         if (!out_of_mem) {
 442                 free(filearg[0]);
 443                 filearg[0] = NULL;
 444         }
 445
 446         free(outname);
 447         outname = NULL;
 448
 449         last_offset = 0;
 450         diff_type = 0;
 451
 452         free(revision);
 453         revision = NULL;
 454
 455         reverse = reverse_flag_specified;
 456         skip_rest_of_patch = false;
 457
 458         get_some_switches();
 459 }
 460
 461 /* Process switches and filenames. */
 462
 463 static void
 464 get_some_switches(void)
 465 {
 466         const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
 467         static struct option longopts[] = {
 468                 {"backup",              no_argument,            0,      'b'},
 469                 {"batch",               no_argument,            0,      't'},
 470                 {"check",               no_argument,            0,      'C'},
 471                 {"context",             no_argument,            0,      'c'},
 472                 {"debug",               required_argument,      0,      'x'},
 473                 {"directory",           required_argument,      0,      'd'},
 474                 {"dry-run",             no_argument,            0,      'C'},
 475                 {"ed",                  no_argument,            0,      'e'},
 476                 {"force",               no_argument,            0,      'f'},
 477                 {"forward",             no_argument,            0,      'N'},
 478                 {"fuzz",                required_argument,      0,      'F'},
 479                 {"ifdef",               required_argument,      0,      'D'},
 480                 {"input",               required_argument,      0,      'i'},
 481                 {"ignore-whitespace",   no_argument,            0,      'l'},
 482                 {"normal",              no_argument,            0,      'n'},
 483                 {"output",              required_argument,      0,      'o'},
 484                 {"prefix",              required_argument,      0,      'B'},
 485                 {"quiet",               no_argument,            0,      's'},
 486                 {"reject-file",         required_argument,      0,      'r'},
 487                 {"remove-empty-files",  no_argument,            0,      'E'},
 488                 {"reverse",             no_argument,            0,      'R'},
 489                 {"silent",              no_argument,            0,      's'},
 490                 {"strip",               required_argument,      0,      'p'},
 491                 {"suffix",              required_argument,      0,      'z'},
 492                 {"unified",             no_argument,            0,      'u'},
 493                 {"version",             no_argument,            0,      'v'},
 494                 {"version-control",     required_argument,      0,      'V'},
 495                 {"posix",               no_argument,            &posix, 1},
 496                 {NULL,                  0,                      0,      0}
 497         };
 498         int ch;
 499
 500         rejname[0] = '\0';
 501         Argc_last = Argc;
 502         Argv_last = Argv;
 503         if (!Argc)
 504                 return;
 505         optreset = optind = 1;
 506         while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
 507                 switch (ch) {
 508                 case 'b':
 509                         if (backup_type == none)
 510                                 backup_type = numbered_existing;
 511                         if (optarg == NULL)
 512                                 break;
 513                         if (verbose)
 514                                 say("Warning, the ``-b suffix'' option has been"
 515                                     " obsoleted by the -z option.\n");
 516                         /* FALLTHROUGH */
 517                 case 'z':
 518                         /* must directly follow 'b' case for backwards compat */
 519                         simple_backup_suffix = xstrdup(optarg);
 520                         break;
 521                 case 'B':
 522                         origprae = xstrdup(optarg);
 523                         break;
 524                 case 'c':
 525                         diff_type = CONTEXT_DIFF;
 526                         break;
 527                 case 'C':
 528                         check_only = true;
 529                         break;
 530                 case 'd':
 531                         if (chdir(optarg) < 0)
 532                                 pfatal("can't cd to %s", optarg);
 533                         break;
 534                 case 'D':
 535                         do_defines = true;
 536                         if (!isalpha((unsigned char)*optarg) && *optarg != '_')
 537                                 fatal("argument to -D is not an identifier\n");
 538                         snprintf(if_defined, sizeof if_defined,
 539                             "#ifdef %s\n", optarg);
 540                         snprintf(not_defined, sizeof not_defined,
 541                             "#ifndef %s\n", optarg);
 542                         snprintf(end_defined, sizeof end_defined,
 543                             "#endif /* %s */\n", optarg);
 544                         break;
 545                 case 'e':
 546                         diff_type = ED_DIFF;
 547                         break;
 548                 case 'E':
 549                         remove_empty_files = true;
 550                         break;
 551                 case 'f':
 552                         force = true;
 553                         break;
 554                 case 'F':
 555                         maxfuzz = atoi(optarg);
 556                         break;
 557                 case 'i':
 558                         if (++filec == MAXFILEC)
 559                                 fatal("too many file arguments\n");
 560                         filearg[filec] = xstrdup(optarg);
 561                         break;
 562                 case 'l':
 563                         canonicalize = true;
 564                         break;
 565                 case 'n':
 566                         diff_type = NORMAL_DIFF;
 567                         break;
 568                 case 'N':
 569                         noreverse = true;
 570                         break;
 571                 case 'o':
 572                         outname = xstrdup(optarg);
 573                         break;
 574                 case 'p':
 575                         strippath = atoi(optarg);
 576                         break;
 577                 case 'r':
 578                         if (strlcpy(rejname, optarg,
 579                             sizeof(rejname)) >= sizeof(rejname))
 580                                 fatal("argument for -r is too long\n");
 581                         break;
 582                 case 'R':
 583                         reverse = true;
 584                         reverse_flag_specified = true;
 585                         break;
 586                 case 's':
 587                         verbose = false;
 588                         break;
 589                 case 't':
 590                         batch = true;
 591                         break;
 592                 case 'u':
 593                         diff_type = UNI_DIFF;
 594                         break;
 595                 case 'v':
 596                         version();
 597                         break;
 598                 case 'V':
 599                         backup_type = get_version(optarg);
 600                         Vflag = true;
 601                         break;
 602 #ifdef DEBUGGING
 603                 case 'x':
 604                         debug = atoi(optarg);
 605                         break;
 606 #endif
 607                 default:
 608                         if (ch != '\0')
 609                                 usage();
 610                         break;
 611                 }
 612         }
 613         Argc -= optind;
 614         Argv += optind;
 615
 616         if (Argc > 0) {
 617                 filearg[0] = xstrdup(*Argv++);
 618                 Argc--;
 619                 while (Argc > 0) {
 620                         if (++filec == MAXFILEC)
 621                                 fatal("too many file arguments\n");
 622                         filearg[filec] = xstrdup(*Argv++);
 623                         Argc--;
 624                 }
 625         }
 626
 627         if (getenv("POSIXLY_CORRECT") != NULL)
 628                 posix = 1;
 629 }
 630
 631 static void
 632 usage(void)
 633 {
 634         fprintf(stderr,
 635 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
 636 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
 637 "             [-r rej-name] [-V t | nil | never | none] [-x number]\n"
 638 "             [-z backup-ext] [--posix] [origfile [patchfile]]\n"
 639 "       patch <patchfile\n");
 640         my_exit(EXIT_FAILURE);
 641 }
 642
 643 /*
 644  * Attempt to find the right place to apply this hunk of patch.
 645  */
 646 static LINENUM
 647 locate_hunk(LINENUM fuzz)
 648 {
 649         LINENUM first_guess = pch_first() + last_offset;
 650         LINENUM offset;
 651         LINENUM pat_lines = pch_ptrn_lines();
 652         LINENUM max_pos_offset = input_lines - first_guess - pat_lines + 1;
 653         LINENUM max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
 654
 655         if (pat_lines == 0) {           /* null range matches always */
 656                 if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
 657                     || diff_type == NEW_CONTEXT_DIFF
 658                     || diff_type == UNI_DIFF)) {
 659                         say("Empty context always matches.\n");
 660                 }
 661                 return (first_guess);
 662         }
 663         if (max_neg_offset >= first_guess)      /* do not try lines < 0 */
 664                 max_neg_offset = first_guess - 1;
 665         if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
 666                 return first_guess;
 667         for (offset = 1; ; offset++) {
 668                 bool    check_after = (offset <= max_pos_offset);
 669                 bool    check_before = (offset <= max_neg_offset);
 670
 671                 if (check_after && patch_match(first_guess, offset, fuzz)) {
 672 #ifdef DEBUGGING
 673                         if (debug & 1)
 674                                 say("Offset changing from %ld to %ld\n",
 675                                     last_offset, offset);
 676 #endif
 677                         last_offset = offset;
 678                         return first_guess + offset;
 679                 } else if (check_before && patch_match(first_guess, -offset, fuzz)) {
 680 #ifdef DEBUGGING
 681                         if (debug & 1)
 682                                 say("Offset changing from %ld to %ld\n",
 683                                     last_offset, -offset);
 684 #endif
 685                         last_offset = -offset;
 686                         return first_guess - offset;
 687                 } else if (!check_before && !check_after)
 688                         return 0;
 689         }
 690 }
 691
 692 /* We did not find the pattern, dump out the hunk so they can handle it. */
 693
 694 static void
 695 abort_context_hunk(void)
 696 {
 697         LINENUM i;
 698         const LINENUM   pat_end = pch_end();
 699         /*
 700          * add in last_offset to guess the same as the previous successful
 701          * hunk
 702          */
 703         const LINENUM   oldfirst = pch_first() + last_offset;
 704         const LINENUM   newfirst = pch_newfirst() + last_offset;
 705         const LINENUM   oldlast = oldfirst + pch_ptrn_lines() - 1;
 706         const LINENUM   newlast = newfirst + pch_repl_lines() - 1;
 707         const char      *stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
 708         const char      *minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
 709
 710         fprintf(rejfp, "***************\n");
 711         for (i = 0; i <= pat_end; i++) {
 712                 switch (pch_char(i)) {
 713                 case '*':
 714                         if (oldlast < oldfirst)
 715                                 fprintf(rejfp, "*** 0%s\n", stars);
 716                         else if (oldlast == oldfirst)
 717                                 fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
 718                         else
 719                                 fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
 720                                     oldlast, stars);
 721                         break;
 722                 case '=':
 723                         if (newlast < newfirst)
 724                                 fprintf(rejfp, "--- 0%s\n", minuses);
 725                         else if (newlast == newfirst)
 726                                 fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
 727                         else
 728                                 fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
 729                                     newlast, minuses);
 730                         break;
 731                 case '\n':
 732                         fprintf(rejfp, "%s", pfetch(i));
 733                         break;
 734                 case ' ':
 735                 case '-':
 736                 case '+':
 737                 case '!':
 738                         fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
 739                         break;
 740                 default:
 741                         fatal("fatal internal error in abort_context_hunk\n");
 742                 }
 743         }
 744 }
 745
 746 static void
 747 rej_line(int ch, LINENUM i)
 748 {
 749         size_t len;
 750         const char *line = pfetch(i);
 751
 752         len = strlen(line);
 753
 754         fprintf(rejfp, "%c%s", ch, line);
 755         if (len == 0 || line[len - 1] != '\n') {
 756                 if (len >= USHRT_MAX)
 757                         fprintf(rejfp, "\n\\ Line too long\n");
 758                 else
 759                         fprintf(rejfp, "\n\\ No newline at end of line\n");
 760         }
 761 }
 762
 763 static void
 764 abort_hunk(void)
 765 {
 766         LINENUM         i, j, split;
 767         int             ch1, ch2;
 768         const LINENUM   pat_end = pch_end();
 769         const LINENUM   oldfirst = pch_first() + last_offset;
 770         const LINENUM   newfirst = pch_newfirst() + last_offset;
 771
 772         if (diff_type != UNI_DIFF) {
 773                 abort_context_hunk();
 774                 return;
 775         }
 776         split = -1;
 777         for (i = 0; i <= pat_end; i++) {
 778                 if (pch_char(i) == '=') {
 779                         split = i;
 780                         break;
 781                 }
 782         }
 783         if (split == -1) {
 784                 fprintf(rejfp, "malformed hunk: no split found\n");
 785                 return;
 786         }
 787         i = 0;
 788         j = split + 1;
 789         fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
 790             pch_ptrn_lines() ? oldfirst : 0,
 791             pch_ptrn_lines(), newfirst, pch_repl_lines());
 792         while (i < split || j <= pat_end) {
 793                 ch1 = i < split ? pch_char(i) : -1;
 794                 ch2 = j <= pat_end ? pch_char(j) : -1;
 795                 if (ch1 == '-') {
 796                         rej_line('-', i);
 797                         i++;
 798                 } else if (ch1 == ' ' && ch2 == ' ') {
 799                         rej_line(' ', i);
 800                         i++;
 801                         j++;
 802                 } else if (ch1 == '!' && ch2 == '!') {
 803                         while (i < split && ch1 == '!') {
 804                                 rej_line('-', i);
 805                                 i++;
 806                                 ch1 = i < split ? pch_char(i) : -1;
 807                         }
 808                         while (j <= pat_end && ch2 == '!') {
 809                                 rej_line('+', j);
 810                                 j++;
 811                                 ch2 = j <= pat_end ? pch_char(j) : -1;
 812                         }
 813                 } else if (ch1 == '*') {
 814                         i++;
 815                 } else if (ch2 == '+' || ch2 == ' ') {
 816                         rej_line(ch2, j);
 817                         j++;
 818                 } else {
 819                         fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
 820                             i, split, j);
 821                         rej_line(ch1, i);
 822                         rej_line(ch2, j);
 823                         return;
 824                 }
 825         }
 826 }
 827
 828 /* We found where to apply it (we hope), so do it. */
 829
 830 static void
 831 apply_hunk(LINENUM where)
 832 {
 833         LINENUM         old = 1;
 834         const LINENUM   lastline = pch_ptrn_lines();
 835         LINENUM         new = lastline + 1;
 836 #define OUTSIDE 0
 837 #define IN_IFNDEF 1
 838 #define IN_IFDEF 2
 839 #define IN_ELSE 3
 840         int             def_state = OUTSIDE;
 841         const LINENUM   pat_end = pch_end();
 842
 843         where--;
 844         while (pch_char(new) == '=' || pch_char(new) == '\n')
 845                 new++;
 846
 847         while (old <= lastline) {
 848                 if (pch_char(old) == '-') {
 849                         copy_till(where + old - 1, false);
 850                         if (do_defines) {
 851                                 if (def_state == OUTSIDE) {
 852                                         fputs(not_defined, ofp);
 853                                         def_state = IN_IFNDEF;
 854                                 } else if (def_state == IN_IFDEF) {
 855                                         fputs(else_defined, ofp);
 856                                         def_state = IN_ELSE;
 857                                 }
 858                                 fputs(pfetch(old), ofp);
 859                         }
 860                         last_frozen_line++;
 861                         old++;
 862                 } else if (new > pat_end) {
 863                         break;
 864                 } else if (pch_char(new) == '+') {
 865                         copy_till(where + old - 1, false);
 866                         if (do_defines) {
 867                                 if (def_state == IN_IFNDEF) {
 868                                         fputs(else_defined, ofp);
 869                                         def_state = IN_ELSE;
 870                                 } else if (def_state == OUTSIDE) {
 871                                         fputs(if_defined, ofp);
 872                                         def_state = IN_IFDEF;
 873                                 }
 874                         }
 875                         fputs(pfetch(new), ofp);
 876                         new++;
 877                 } else if (pch_char(new) != pch_char(old)) {
 878                         say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
 879                             pch_hunk_beg() + old,
 880                             pch_hunk_beg() + new);
 881 #ifdef DEBUGGING
 882                         say("oldchar = '%c', newchar = '%c'\n",
 883                             pch_char(old), pch_char(new));
 884 #endif
 885                         my_exit(2);
 886                 } else if (pch_char(new) == '!') {
 887                         copy_till(where + old - 1, false);
 888                         if (do_defines) {
 889                                 fputs(not_defined, ofp);
 890                                 def_state = IN_IFNDEF;
 891                         }
 892                         while (pch_char(old) == '!') {
 893                                 if (do_defines) {
 894                                         fputs(pfetch(old), ofp);
 895                                 }
 896                                 last_frozen_line++;
 897                                 old++;
 898                         }
 899                         if (do_defines) {
 900                                 fputs(else_defined, ofp);
 901                                 def_state = IN_ELSE;
 902                         }
 903                         while (pch_char(new) == '!') {
 904                                 fputs(pfetch(new), ofp);
 905                                 new++;
 906                         }
 907                 } else {
 908                         if (pch_char(new) != ' ')
 909                                 fatal("Internal error: expected ' '\n");
 910                         old++;
 911                         new++;
 912                         if (do_defines && def_state != OUTSIDE) {
 913                                 fputs(end_defined, ofp);
 914                                 def_state = OUTSIDE;
 915                         }
 916                 }
 917         }
 918         if (new <= pat_end && pch_char(new) == '+') {
 919                 copy_till(where + old - 1, false);
 920                 if (do_defines) {
 921                         if (def_state == OUTSIDE) {
 922                                 fputs(if_defined, ofp);
 923                                 def_state = IN_IFDEF;
 924                         } else if (def_state == IN_IFNDEF) {
 925                                 fputs(else_defined, ofp);
 926                                 def_state = IN_ELSE;
 927                         }
 928                 }
 929                 while (new <= pat_end && pch_char(new) == '+') {
 930                         fputs(pfetch(new), ofp);
 931                         new++;
 932                 }
 933         }
 934         if (do_defines && def_state != OUTSIDE) {
 935                 fputs(end_defined, ofp);
 936         }
 937 }
 938
 939 /*
 940  * Open the new file.
 941  */
 942 static void
 943 init_output(const char *name)
 944 {
 945         ofp = fopen(name, "w");
 946         if (ofp == NULL)
 947                 pfatal("can't create %s", name);
 948 }
 949
 950 /*
 951  * Open a file to put hunks we can't locate.
 952  */
 953 static void
 954 init_reject(const char *name)
 955 {
 956         rejfp = fopen(name, "w");
 957         if (rejfp == NULL)
 958                 pfatal("can't create %s", name);
 959 }
 960
 961 /*
 962  * Copy input file to output, up to wherever hunk is to be applied.
 963  * If endoffile is true, treat the last line specially since it may
 964  * lack a newline.
 965  */
 966 static void
 967 copy_till(LINENUM lastline, bool endoffile)
 968 {
 969         if (last_frozen_line > lastline)
 970                 fatal("misordered hunks! output would be garbled\n");
 971         while (last_frozen_line < lastline) {
 972                 if (++last_frozen_line == lastline && endoffile)
 973                         dump_line(last_frozen_line, !last_line_missing_eol);
 974                 else
 975                         dump_line(last_frozen_line, true);
 976         }
 977 }
 978
 979 /*
 980  * Finish copying the input file to the output file.
 981  */
 982 static bool
 983 spew_output(void)
 984 {
 985         int rv;
 986
 987 #ifdef DEBUGGING
 988         if (debug & 256)
 989                 say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
 990 #endif
 991         if (input_lines)
 992                 copy_till(input_lines, true);   /* dump remainder of file */
 993         rv = ferror(ofp) == 0 && fclose(ofp) == 0;
 994         ofp = NULL;
 995         return rv;
 996 }
 997
 998 /*
 999  * Copy one line from input to output.
1000  */
1001 static void
1002 dump_line(LINENUM line, bool write_newline)
1003 {
1004         char    *s;
1005
1006         s = ifetch(line, 0);
1007         if (s == NULL)
1008                 return;
1009         /* Note: string is not NUL terminated. */
1010         for (; *s != '\n'; s++)
1011                 putc(*s, ofp);
1012         if (write_newline)
1013                 putc('\n', ofp);
1014 }
1015
1016 /*
1017  * Does the patch pattern match at line base+offset?
1018  */
1019 static bool
1020 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1021 {
1022         LINENUM         pline = 1 + fuzz;
1023         LINENUM         iline;
1024         LINENUM         pat_lines = pch_ptrn_lines() - fuzz;
1025         const char      *ilineptr;
1026         const char      *plineptr;
1027         unsigned short  plinelen;
1028
1029         /* Patch does not match if we don't have any more context to use */
1030         if (pline > pat_lines)
1031                 return false;
1032         for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1033                 ilineptr = ifetch(iline, offset >= 0);
1034                 if (ilineptr == NULL)
1035                         return false;
1036                 plineptr = pfetch(pline);
1037                 plinelen = pch_line_len(pline);
1038                 if (canonicalize) {
1039                         if (!similar(ilineptr, plineptr, plinelen))
1040                                 return false;
1041                 } else if (strnNE(ilineptr, plineptr, plinelen))
1042                         return false;
1043                 if (iline == input_lines) {
1044                         /*
1045                          * We are looking at the last line of the file.
1046                          * If the file has no eol, the patch line should
1047                          * not have one either and vice-versa. Note that
1048                          * plinelen > 0.
1049                          */
1050                         if (last_line_missing_eol) {
1051                                 if (plineptr[plinelen - 1] == '\n')
1052                                         return false;
1053                         } else {
1054                                 if (plineptr[plinelen - 1] != '\n')
1055                                         return false;
1056                         }
1057                 }
1058         }
1059         return true;
1060 }
1061
1062 /*
1063  * Do two lines match with canonicalized white space?
1064  */
1065 static bool
1066 similar(const char *a, const char *b, int len)
1067 {
1068         while (len) {
1069                 if (isspace((unsigned char)*b)) {       /* whitespace (or \n) to match? */
1070                         if (!isspace((unsigned char)*a))        /* no corresponding whitespace? */
1071                                 return false;
1072                         while (len && isspace((unsigned char)*b) && *b != '\n')
1073                                 b++, len--;     /* skip pattern whitespace */
1074                         while (isspace((unsigned char)*a) && *a != '\n')
1075                                 a++;    /* skip target whitespace */
1076                         if (*a == '\n' || *b == '\n')
1077                                 return (*a == *b);      /* should end in sync */
1078                 } else if (*a++ != *b++)        /* match non-whitespace chars */
1079                         return false;
1080                 else
1081                         len--;  /* probably not necessary */
1082         }
1083         return true;            /* actually, this is not reached */
1084         /* since there is always a \n */
1085 }