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: head/usr.bin/patch/patch.c 255894 2013-09-26 18:00:45Z delphij $
  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, reverse_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                 reverse_seen = false;
 251                 out_of_mem = false;
 252                 while (another_hunk()) {
 253                         hunk++;
 254                         fuzz = 0;
 255                         mymaxfuzz = pch_context();
 256                         if (maxfuzz < mymaxfuzz)
 257                                 mymaxfuzz = maxfuzz;
 258                         if (!skip_rest_of_patch) {
 259                                 do {
 260                                         where = locate_hunk(fuzz);
 261                                         if (hunk == 1 && where == 0 && !force && !reverse_seen) {
 262                                                 /* dwim for reversed patch? */
 263                                                 if (!pch_swap()) {
 264                                                         if (fuzz == 0)
 265                                                                 say("Not enough memory to try swapped hunk!  Assuming unswapped.\n");
 266                                                         continue;
 267                                                 }
 268                                                 reverse = !reverse;
 269                                                 /* try again */
 270                                                 where = locate_hunk(fuzz);
 271                                                 if (where == 0) {
 272                                                         /* didn't find it swapped */
 273                                                         if (!pch_swap())
 274                                                                 /* put it back to normal */
 275                                                                 fatal("lost hunk on alloc error!\n");
 276                                                         reverse = !reverse;
 277                                                 } else if (noreverse) {
 278                                                         if (!pch_swap())
 279                                                                 /* put it back to normal */
 280                                                                 fatal("lost hunk on alloc error!\n");
 281                                                         reverse = !reverse;
 282                                                         say("Ignoring previously applied (or reversed) patch.\n");
 283                                                         skip_rest_of_patch = true;
 284                                                 } else if (batch) {
 285                                                         if (verbose)
 286                                                                 say("%seversed (or previously applied) patch detected!  %s -R.",
 287                                                                     reverse ? "R" : "Unr",
 288                                                                     reverse ? "Assuming" : "Ignoring");
 289                                                 } else {
 290                                                         ask("%seversed (or previously applied) patch detected!  %s -R? [y] ",
 291                                                             reverse ? "R" : "Unr",
 292                                                             reverse ? "Assume" : "Ignore");
 293                                                         if (*buf == 'n') {
 294                                                                 ask("Apply anyway? [n] ");
 295                                                                 if (*buf != 'y')
 296                                                                         skip_rest_of_patch = true;
 297                                                                 else
 298                                                                         reverse_seen = true;
 299                                                                 where = 0;
 300                                                                 reverse = !reverse;
 301                                                                 if (!pch_swap())
 302                                                                         /* put it back to normal */
 303                                                                         fatal("lost hunk on alloc error!\n");
 304                                                         }
 305                                                 }
 306                                         }
 307                                 } while (!skip_rest_of_patch && where == 0 &&
 308                                     ++fuzz <= mymaxfuzz);
 309
 310                                 if (skip_rest_of_patch) {       /* just got decided */
 311                                         if (ferror(ofp) || fclose(ofp)) {
 312                                                 say("Error writing %s\n",
 313                                                     TMPOUTNAME);
 314                                                 error = 1;
 315                                         }
 316                                         ofp = NULL;
 317                                 }
 318                         }
 319                         newwhere = pch_newfirst() + last_offset;
 320                         if (skip_rest_of_patch) {
 321                                 abort_hunk();
 322                                 failed++;
 323                                 if (verbose)
 324                                         say("Hunk #%d ignored at %ld.\n",
 325                                             hunk, newwhere);
 326                         } else if (where == 0) {
 327                                 abort_hunk();
 328                                 failed++;
 329                                 if (verbose)
 330                                         say("Hunk #%d failed at %ld.\n",
 331                                             hunk, newwhere);
 332                         } else {
 333                                 apply_hunk(where);
 334                                 if (verbose) {
 335                                         say("Hunk #%d succeeded at %ld",
 336                                             hunk, newwhere);
 337                                         if (fuzz != 0)
 338                                                 say(" with fuzz %ld", fuzz);
 339                                         if (last_offset)
 340                                                 say(" (offset %ld line%s)",
 341                                                     last_offset,
 342                                                     last_offset == 1L ? "" : "s");
 343                                         say(".\n");
 344                                 }
 345                         }
 346                 }
 347
 348                 if (out_of_mem && using_plan_a) {
 349                         Argc = Argc_last;
 350                         Argv = Argv_last;
 351                         say("\n\nRan out of memory using Plan A--trying again...\n\n");
 352                         if (ofp)
 353                                 fclose(ofp);
 354                         ofp = NULL;
 355                         if (rejfp)
 356                                 fclose(rejfp);
 357                         rejfp = NULL;
 358                         continue;
 359                 }
 360                 if (hunk == 0)
 361                         fatal("Internal error: hunk should not be 0\n");
 362
 363                 /* finish spewing out the new file */
 364                 if (!skip_rest_of_patch && !spew_output()) {
 365                         say("Can't write %s\n", TMPOUTNAME);
 366                         error = 1;
 367                 }
 368
 369                 /* and put the output where desired */
 370                 ignore_signals();
 371                 if (!skip_rest_of_patch) {
 372                         struct stat     statbuf;
 373                         char    *realout = outname;
 374
 375                         if (!check_only) {
 376                                 if (move_file(TMPOUTNAME, outname) < 0) {
 377                                         toutkeep = true;
 378                                         realout = TMPOUTNAME;
 379                                         chmod(TMPOUTNAME, filemode);
 380                                 } else
 381                                         chmod(outname, filemode);
 382
 383                                 if (remove_empty_files &&
 384                                     stat(realout, &statbuf) == 0 &&
 385                                     statbuf.st_size == 0) {
 386                                         if (verbose)
 387                                                 say("Removing %s (empty after patching).\n",
 388                                                     realout);
 389                                         unlink(realout);
 390                                 }
 391                         }
 392                 }
 393                 if (ferror(rejfp) || fclose(rejfp)) {
 394                         say("Error writing %s\n", rejname);
 395                         error = 1;
 396                 }
 397                 rejfp = NULL;
 398                 if (failed) {
 399                         error = 1;
 400                         if (*rejname == '\0') {
 401                                 if (strlcpy(rejname, outname,
 402                                     sizeof(rejname)) >= sizeof(rejname))
 403                                         fatal("filename %s is too long\n", outname);
 404                                 if (strlcat(rejname, REJEXT,
 405                                     sizeof(rejname)) >= sizeof(rejname))
 406                                         fatal("filename %s is too long\n", outname);
 407                         }
 408                         if (!check_only)
 409                                 say("%d out of %d hunks %s--saving rejects to %s\n",
 410                                     failed, hunk, skip_rest_of_patch ? "ignored" : "failed", rejname);
 411                         else
 412                                 say("%d out of %d hunks %s while patching %s\n",
 413                                     failed, hunk, skip_rest_of_patch ? "ignored" : "failed", filearg[0]);
 414                         if (!check_only && move_file(TMPREJNAME, rejname) < 0)
 415                                 trejkeep = true;
 416                 }
 417                 set_signals(1);
 418         }
 419
 420         if (!patch_seen)
 421                 error = 2;
 422
 423         my_exit(error);
 424         /* NOTREACHED */
 425 }
 426
 427 /* Prepare to find the next patch to do in the patch file. */
 428
 429 static void
 430 reinitialize_almost_everything(void)
 431 {
 432         re_patch();
 433         re_input();
 434
 435         input_lines = 0;
 436         last_frozen_line = 0;
 437
 438         filec = 0;
 439         if (!out_of_mem) {
 440                 free(filearg[0]);
 441                 filearg[0] = NULL;
 442         }
 443
 444         free(outname);
 445         outname = NULL;
 446
 447         last_offset = 0;
 448         diff_type = 0;
 449
 450         free(revision);
 451         revision = NULL;
 452
 453         reverse = reverse_flag_specified;
 454         skip_rest_of_patch = false;
 455
 456         get_some_switches();
 457 }
 458
 459 /* Process switches and filenames. */
 460
 461 static void
 462 get_some_switches(void)
 463 {
 464         const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
 465         static struct option longopts[] = {
 466                 {"backup",              no_argument,            0,      'b'},
 467                 {"batch",               no_argument,            0,      't'},
 468                 {"check",               no_argument,            0,      'C'},
 469                 {"context",             no_argument,            0,      'c'},
 470                 {"debug",               required_argument,      0,      'x'},
 471                 {"directory",           required_argument,      0,      'd'},
 472                 {"ed",                  no_argument,            0,      'e'},
 473                 {"force",               no_argument,            0,      'f'},
 474                 {"forward",             no_argument,            0,      'N'},
 475                 {"fuzz",                required_argument,      0,      'F'},
 476                 {"ifdef",               required_argument,      0,      'D'},
 477                 {"input",               required_argument,      0,      'i'},
 478                 {"ignore-whitespace",   no_argument,            0,      'l'},
 479                 {"normal",              no_argument,            0,      'n'},
 480                 {"output",              required_argument,      0,      'o'},
 481                 {"prefix",              required_argument,      0,      'B'},
 482                 {"quiet",               no_argument,            0,      's'},
 483                 {"reject-file",         required_argument,      0,      'r'},
 484                 {"remove-empty-files",  no_argument,            0,      'E'},
 485                 {"reverse",             no_argument,            0,      'R'},
 486                 {"silent",              no_argument,            0,      's'},
 487                 {"strip",               required_argument,      0,      'p'},
 488                 {"suffix",              required_argument,      0,      'z'},
 489                 {"unified",             no_argument,            0,      'u'},
 490                 {"version",             no_argument,            0,      'v'},
 491                 {"version-control",     required_argument,      0,      'V'},
 492                 {"posix",               no_argument,            &posix, 1},
 493                 {NULL,                  0,                      0,      0}
 494         };
 495         int ch;
 496
 497         rejname[0] = '\0';
 498         Argc_last = Argc;
 499         Argv_last = Argv;
 500         if (!Argc)
 501                 return;
 502         optreset = optind = 1;
 503         while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
 504                 switch (ch) {
 505                 case 'b':
 506                         if (backup_type == none)
 507                                 backup_type = numbered_existing;
 508                         if (optarg == NULL)
 509                                 break;
 510                         if (verbose)
 511                                 say("Warning, the ``-b suffix'' option has been"
 512                                     " obsoleted by the -z option.\n");
 513                         /* FALLTHROUGH */
 514                 case 'z':
 515                         /* must directly follow 'b' case for backwards compat */
 516                         simple_backup_suffix = savestr(optarg);
 517                         break;
 518                 case 'B':
 519                         origprae = savestr(optarg);
 520                         break;
 521                 case 'c':
 522                         diff_type = CONTEXT_DIFF;
 523                         break;
 524                 case 'C':
 525                         check_only = true;
 526                         break;
 527                 case 'd':
 528                         if (chdir(optarg) < 0)
 529                                 pfatal("can't cd to %s", optarg);
 530                         break;
 531                 case 'D':
 532                         do_defines = true;
 533                         if (!isalpha((unsigned char)*optarg) && *optarg != '_')
 534                                 fatal("argument to -D is not an identifier\n");
 535                         snprintf(if_defined, sizeof if_defined,
 536                             "#ifdef %s\n", optarg);
 537                         snprintf(not_defined, sizeof not_defined,
 538                             "#ifndef %s\n", optarg);
 539                         snprintf(end_defined, sizeof end_defined,
 540                             "#endif /* %s */\n", optarg);
 541                         break;
 542                 case 'e':
 543                         diff_type = ED_DIFF;
 544                         break;
 545                 case 'E':
 546                         remove_empty_files = true;
 547                         break;
 548                 case 'f':
 549                         force = true;
 550                         break;
 551                 case 'F':
 552                         maxfuzz = atoi(optarg);
 553                         break;
 554                 case 'i':
 555                         if (++filec == MAXFILEC)
 556                                 fatal("too many file arguments\n");
 557                         filearg[filec] = savestr(optarg);
 558                         break;
 559                 case 'l':
 560                         canonicalize = true;
 561                         break;
 562                 case 'n':
 563                         diff_type = NORMAL_DIFF;
 564                         break;
 565                 case 'N':
 566                         noreverse = true;
 567                         break;
 568                 case 'o':
 569                         outname = savestr(optarg);
 570                         break;
 571                 case 'p':
 572                         strippath = atoi(optarg);
 573                         break;
 574                 case 'r':
 575                         if (strlcpy(rejname, optarg,
 576                             sizeof(rejname)) >= sizeof(rejname))
 577                                 fatal("argument for -r is too long\n");
 578                         break;
 579                 case 'R':
 580                         reverse = true;
 581                         reverse_flag_specified = true;
 582                         break;
 583                 case 's':
 584                         verbose = false;
 585                         break;
 586                 case 't':
 587                         batch = true;
 588                         break;
 589                 case 'u':
 590                         diff_type = UNI_DIFF;
 591                         break;
 592                 case 'v':
 593                         version();
 594                         break;
 595                 case 'V':
 596                         backup_type = get_version(optarg);
 597                         break;
 598 #ifdef DEBUGGING
 599                 case 'x':
 600                         debug = atoi(optarg);
 601                         break;
 602 #endif
 603                 default:
 604                         if (ch != '\0')
 605                                 usage();
 606                         break;
 607                 }
 608         }
 609         Argc -= optind;
 610         Argv += optind;
 611
 612         if (Argc > 0) {
 613                 filearg[0] = savestr(*Argv++);
 614                 Argc--;
 615                 while (Argc > 0) {
 616                         if (++filec == MAXFILEC)
 617                                 fatal("too many file arguments\n");
 618                         filearg[filec] = savestr(*Argv++);
 619                         Argc--;
 620                 }
 621         }
 622
 623         if (getenv("POSIXLY_CORRECT") != NULL)
 624                 posix = 1;
 625 }
 626
 627 static void
 628 usage(void)
 629 {
 630         fprintf(stderr,
 631 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
 632 "             [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
 633 "             [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
 634 "             [--posix] [origfile [patchfile]]\n"
 635 "       patch <patchfile\n");
 636         my_exit(EXIT_SUCCESS);
 637 }
 638
 639 /*
 640  * Attempt to find the right place to apply this hunk of patch.
 641  */
 642 static LINENUM
 643 locate_hunk(LINENUM fuzz)
 644 {
 645         LINENUM first_guess = pch_first() + last_offset;
 646         LINENUM offset;
 647         LINENUM pat_lines = pch_ptrn_lines();
 648         LINENUM max_pos_offset = input_lines - first_guess - pat_lines + 1;
 649         LINENUM max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
 650
 651         if (pat_lines == 0) {           /* null range matches always */
 652                 if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
 653                     || diff_type == NEW_CONTEXT_DIFF
 654                     || diff_type == UNI_DIFF)) {
 655                         say("Empty context always matches.\n");
 656                 }
 657                 return (first_guess);
 658         }
 659         if (max_neg_offset >= first_guess)      /* do not try lines < 0 */
 660                 max_neg_offset = first_guess - 1;
 661         if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
 662                 return first_guess;
 663         for (offset = 1; ; offset++) {
 664                 bool    check_after = (offset <= max_pos_offset);
 665                 bool    check_before = (offset <= max_neg_offset);
 666
 667                 if (check_after && patch_match(first_guess, offset, fuzz)) {
 668 #ifdef DEBUGGING
 669                         if (debug & 1)
 670                                 say("Offset changing from %ld to %ld\n",
 671                                     last_offset, offset);
 672 #endif
 673                         last_offset = offset;
 674                         return first_guess + offset;
 675                 } else if (check_before && patch_match(first_guess, -offset, fuzz)) {
 676 #ifdef DEBUGGING
 677                         if (debug & 1)
 678                                 say("Offset changing from %ld to %ld\n",
 679                                     last_offset, -offset);
 680 #endif
 681                         last_offset = -offset;
 682                         return first_guess - offset;
 683                 } else if (!check_before && !check_after)
 684                         return 0;
 685         }
 686 }
 687
 688 /* We did not find the pattern, dump out the hunk so they can handle it. */
 689
 690 static void
 691 abort_context_hunk(void)
 692 {
 693         LINENUM i;
 694         const LINENUM   pat_end = pch_end();
 695         /*
 696          * add in last_offset to guess the same as the previous successful
 697          * hunk
 698          */
 699         const LINENUM   oldfirst = pch_first() + last_offset;
 700         const LINENUM   newfirst = pch_newfirst() + last_offset;
 701         const LINENUM   oldlast = oldfirst + pch_ptrn_lines() - 1;
 702         const LINENUM   newlast = newfirst + pch_repl_lines() - 1;
 703         const char      *stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
 704         const char      *minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
 705
 706         fprintf(rejfp, "***************\n");
 707         for (i = 0; i <= pat_end; i++) {
 708                 switch (pch_char(i)) {
 709                 case '*':
 710                         if (oldlast < oldfirst)
 711                                 fprintf(rejfp, "*** 0%s\n", stars);
 712                         else if (oldlast == oldfirst)
 713                                 fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
 714                         else
 715                                 fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
 716                                     oldlast, stars);
 717                         break;
 718                 case '=':
 719                         if (newlast < newfirst)
 720                                 fprintf(rejfp, "--- 0%s\n", minuses);
 721                         else if (newlast == newfirst)
 722                                 fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
 723                         else
 724                                 fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
 725                                     newlast, minuses);
 726                         break;
 727                 case '\n':
 728                         fprintf(rejfp, "%s", pfetch(i));
 729                         break;
 730                 case ' ':
 731                 case '-':
 732                 case '+':
 733                 case '!':
 734                         fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
 735                         break;
 736                 default:
 737                         fatal("fatal internal error in abort_context_hunk\n");
 738                 }
 739         }
 740 }
 741
 742 static void
 743 rej_line(int ch, LINENUM i)
 744 {
 745         size_t len;
 746         const char *line = pfetch(i);
 747
 748         len = strlen(line);
 749
 750         fprintf(rejfp, "%c%s", ch, line);
 751         if (len == 0 || line[len-1] != '\n')
 752                 fprintf(rejfp, "\n\\ No newline at end of file\n");
 753 }
 754
 755 static void
 756 abort_hunk(void)
 757 {
 758         LINENUM         i, j, split;
 759         int             ch1, ch2;
 760         const LINENUM   pat_end = pch_end();
 761         const LINENUM   oldfirst = pch_first() + last_offset;
 762         const LINENUM   newfirst = pch_newfirst() + last_offset;
 763
 764         if (diff_type != UNI_DIFF) {
 765                 abort_context_hunk();
 766                 return;
 767         }
 768         split = -1;
 769         for (i = 0; i <= pat_end; i++) {
 770                 if (pch_char(i) == '=') {
 771                         split = i;
 772                         break;
 773                 }
 774         }
 775         if (split == -1) {
 776                 fprintf(rejfp, "malformed hunk: no split found\n");
 777                 return;
 778         }
 779         i = 0;
 780         j = split + 1;
 781         fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
 782             pch_ptrn_lines() ? oldfirst : 0,
 783             pch_ptrn_lines(), newfirst, pch_repl_lines());
 784         while (i < split || j <= pat_end) {
 785                 ch1 = i < split ? pch_char(i) : -1;
 786                 ch2 = j <= pat_end ? pch_char(j) : -1;
 787                 if (ch1 == '-') {
 788                         rej_line('-', i);
 789                         i++;
 790                 } else if (ch1 == ' ' && ch2 == ' ') {
 791                         rej_line(' ', i);
 792                         i++;
 793                         j++;
 794                 } else if (ch1 == '!' && ch2 == '!') {
 795                         while (i < split && ch1 == '!') {
 796                                 rej_line('-', i);
 797                                 i++;
 798                                 ch1 = i < split ? pch_char(i) : -1;
 799                         }
 800                         while (j <= pat_end && ch2 == '!') {
 801                                 rej_line('+', j);
 802                                 j++;
 803                                 ch2 = j <= pat_end ? pch_char(j) : -1;
 804                         }
 805                 } else if (ch1 == '*') {
 806                         i++;
 807                 } else if (ch2 == '+' || ch2 == ' ') {
 808                         rej_line(ch2, j);
 809                         j++;
 810                 } else {
 811                         fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
 812                             i, split, j);
 813                         rej_line(ch1, i);
 814                         rej_line(ch2, j);
 815                         return;
 816                 }
 817         }
 818 }
 819
 820 /* We found where to apply it (we hope), so do it. */
 821
 822 static void
 823 apply_hunk(LINENUM where)
 824 {
 825         LINENUM         old = 1;
 826         const LINENUM   lastline = pch_ptrn_lines();
 827         LINENUM         new = lastline + 1;
 828 #define OUTSIDE 0
 829 #define IN_IFNDEF 1
 830 #define IN_IFDEF 2
 831 #define IN_ELSE 3
 832         int             def_state = OUTSIDE;
 833         const LINENUM   pat_end = pch_end();
 834
 835         where--;
 836         while (pch_char(new) == '=' || pch_char(new) == '\n')
 837                 new++;
 838
 839         while (old <= lastline) {
 840                 if (pch_char(old) == '-') {
 841                         copy_till(where + old - 1, false);
 842                         if (do_defines) {
 843                                 if (def_state == OUTSIDE) {
 844                                         fputs(not_defined, ofp);
 845                                         def_state = IN_IFNDEF;
 846                                 } else if (def_state == IN_IFDEF) {
 847                                         fputs(else_defined, ofp);
 848                                         def_state = IN_ELSE;
 849                                 }
 850                                 fputs(pfetch(old), ofp);
 851                         }
 852                         last_frozen_line++;
 853                         old++;
 854                 } else if (new > pat_end) {
 855                         break;
 856                 } else if (pch_char(new) == '+') {
 857                         copy_till(where + old - 1, false);
 858                         if (do_defines) {
 859                                 if (def_state == IN_IFNDEF) {
 860                                         fputs(else_defined, ofp);
 861                                         def_state = IN_ELSE;
 862                                 } else if (def_state == OUTSIDE) {
 863                                         fputs(if_defined, ofp);
 864                                         def_state = IN_IFDEF;
 865                                 }
 866                         }
 867                         fputs(pfetch(new), ofp);
 868                         new++;
 869                 } else if (pch_char(new) != pch_char(old)) {
 870                         say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
 871                             pch_hunk_beg() + old,
 872                             pch_hunk_beg() + new);
 873 #ifdef DEBUGGING
 874                         say("oldchar = '%c', newchar = '%c'\n",
 875                             pch_char(old), pch_char(new));
 876 #endif
 877                         my_exit(2);
 878                 } else if (pch_char(new) == '!') {
 879                         copy_till(where + old - 1, false);
 880                         if (do_defines) {
 881                                 fputs(not_defined, ofp);
 882                                 def_state = IN_IFNDEF;
 883                         }
 884                         while (pch_char(old) == '!') {
 885                                 if (do_defines) {
 886                                         fputs(pfetch(old), ofp);
 887                                 }
 888                                 last_frozen_line++;
 889                                 old++;
 890                         }
 891                         if (do_defines) {
 892                                 fputs(else_defined, ofp);
 893                                 def_state = IN_ELSE;
 894                         }
 895                         while (pch_char(new) == '!') {
 896                                 fputs(pfetch(new), ofp);
 897                                 new++;
 898                         }
 899                 } else {
 900                         if (pch_char(new) != ' ')
 901                                 fatal("Internal error: expected ' '\n");
 902                         old++;
 903                         new++;
 904                         if (do_defines && def_state != OUTSIDE) {
 905                                 fputs(end_defined, ofp);
 906                                 def_state = OUTSIDE;
 907                         }
 908                 }
 909         }
 910         if (new <= pat_end && pch_char(new) == '+') {
 911                 copy_till(where + old - 1, false);
 912                 if (do_defines) {
 913                         if (def_state == OUTSIDE) {
 914                                 fputs(if_defined, ofp);
 915                                 def_state = IN_IFDEF;
 916                         } else if (def_state == IN_IFNDEF) {
 917                                 fputs(else_defined, ofp);
 918                                 def_state = IN_ELSE;
 919                         }
 920                 }
 921                 while (new <= pat_end && pch_char(new) == '+') {
 922                         fputs(pfetch(new), ofp);
 923                         new++;
 924                 }
 925         }
 926         if (do_defines && def_state != OUTSIDE) {
 927                 fputs(end_defined, ofp);
 928         }
 929 }
 930
 931 /*
 932  * Open the new file.
 933  */
 934 static void
 935 init_output(const char *name)
 936 {
 937         ofp = fopen(name, "w");
 938         if (ofp == NULL)
 939                 pfatal("can't create %s", name);
 940 }
 941
 942 /*
 943  * Open a file to put hunks we can't locate.
 944  */
 945 static void
 946 init_reject(const char *name)
 947 {
 948         rejfp = fopen(name, "w");
 949         if (rejfp == NULL)
 950                 pfatal("can't create %s", name);
 951 }
 952
 953 /*
 954  * Copy input file to output, up to wherever hunk is to be applied.
 955  * If endoffile is true, treat the last line specially since it may
 956  * lack a newline.
 957  */
 958 static void
 959 copy_till(LINENUM lastline, bool endoffile)
 960 {
 961         if (last_frozen_line > lastline)
 962                 fatal("misordered hunks! output would be garbled\n");
 963         while (last_frozen_line < lastline) {
 964                 if (++last_frozen_line == lastline && endoffile)
 965                         dump_line(last_frozen_line, !last_line_missing_eol);
 966                 else
 967                         dump_line(last_frozen_line, true);
 968         }
 969 }
 970
 971 /*
 972  * Finish copying the input file to the output file.
 973  */
 974 static bool
 975 spew_output(void)
 976 {
 977         int rv;
 978
 979 #ifdef DEBUGGING
 980         if (debug & 256)
 981                 say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
 982 #endif
 983         if (input_lines)
 984                 copy_till(input_lines, true);   /* dump remainder of file */
 985         rv = ferror(ofp) == 0 && fclose(ofp) == 0;
 986         ofp = NULL;
 987         return rv;
 988 }
 989
 990 /*
 991  * Copy one line from input to output.
 992  */
 993 static void
 994 dump_line(LINENUM line, bool write_newline)
 995 {
 996         char    *s;
 997
 998         s = ifetch(line, 0);
 999         if (s == NULL)
1000                 return;
1001         /* Note: string is not NUL terminated. */
1002         for (; *s != '\n'; s++)
1003                 putc(*s, ofp);
1004         if (write_newline)
1005                 putc('\n', ofp);
1006 }
1007
1008 /*
1009  * Does the patch pattern match at line base+offset?
1010  */
1011 static bool
1012 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1013 {
1014         LINENUM         pline = 1 + fuzz;
1015         LINENUM         iline;
1016         LINENUM         pat_lines = pch_ptrn_lines() - fuzz;
1017         const char      *ilineptr;
1018         const char      *plineptr;
1019         short           plinelen;
1020
1021         for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1022                 ilineptr = ifetch(iline, offset >= 0);
1023                 if (ilineptr == NULL)
1024                         return false;
1025                 plineptr = pfetch(pline);
1026                 plinelen = pch_line_len(pline);
1027                 if (canonicalize) {
1028                         if (!similar(ilineptr, plineptr, plinelen))
1029                                 return false;
1030                 } else if (strnNE(ilineptr, plineptr, plinelen))
1031                         return false;
1032                 if (iline == input_lines) {
1033                         /*
1034                          * We are looking at the last line of the file.
1035                          * If the file has no eol, the patch line should
1036                          * not have one either and vice-versa. Note that
1037                          * plinelen > 0.
1038                          */
1039                         if (last_line_missing_eol) {
1040                                 if (plineptr[plinelen - 1] == '\n')
1041                                         return false;
1042                         } else {
1043                                 if (plineptr[plinelen - 1] != '\n')
1044                                         return false;
1045                         }
1046                 }
1047         }
1048         return true;
1049 }
1050
1051 /*
1052  * Do two lines match with canonicalized white space?
1053  */
1054 static bool
1055 similar(const char *a, const char *b, int len)
1056 {
1057         while (len) {
1058                 if (isspace((unsigned char)*b)) {       /* whitespace (or \n) to match? */
1059                         if (!isspace((unsigned char)*a))        /* no corresponding whitespace? */
1060                                 return false;
1061                         while (len && isspace((unsigned char)*b) && *b != '\n')
1062                                 b++, len--;     /* skip pattern whitespace */
1063                         while (isspace((unsigned char)*a) && *a != '\n')
1064                                 a++;    /* skip target whitespace */
1065                         if (*a == '\n' || *b == '\n')
1066                                 return (*a == *b);      /* should end in sync */
1067                 } else if (*a++ != *b++)        /* match non-whitespace chars */
1068                         return false;
1069                 else
1070                         len--;  /* probably not necessary */
1071         }
1072         return true;            /* actually, this is not reached */
1073         /* since there is always a \n */
1074 }