usr.bin/patch/pch.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: pch.c,v 1.43 2014/11/18 17:03:35 tobias Exp $
  27  * $FreeBSD$
  28  */
  29
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32
  33 #include <ctype.h>
  34 #include <libgen.h>
  35 #include <limits.h>
  36 #include <stdint.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42 #include "common.h"
  43 #include "util.h"
  44 #include "pch.h"
  45 #include "pathnames.h"
  46
  47 /* Patch (diff listing) abstract type. */
  48
  49 static off_t    p_filesize;     /* size of the patch file */
  50 static LINENUM  p_first;        /* 1st line number */
  51 static LINENUM  p_newfirst;     /* 1st line number of replacement */
  52 static LINENUM  p_ptrn_lines;   /* # lines in pattern */
  53 static LINENUM  p_repl_lines;   /* # lines in replacement text */
  54 static LINENUM  p_end = -1;     /* last line in hunk */
  55 static LINENUM  p_max;          /* max allowed value of p_end */
  56 static LINENUM  p_context = 3;  /* # of context lines */
  57 static LINENUM  p_input_line = 0;       /* current line # from patch file */
  58 static char     **p_line = NULL;/* the text of the hunk */
  59 static unsigned short   *p_len = NULL; /* length of each line */
  60 static char     *p_char = NULL; /* +, -, and ! */
  61 static int      hunkmax = INITHUNKMAX;  /* size of above arrays to begin with */
  62 static int      p_indent;       /* indent to patch */
  63 static off_t    p_base;         /* where to intuit this time */
  64 static LINENUM  p_bline;        /* line # of p_base */
  65 static off_t    p_start;        /* where intuit found a patch */
  66 static LINENUM  p_sline;        /* and the line number for it */
  67 static LINENUM  p_hunk_beg;     /* line number of current hunk */
  68 static LINENUM  p_efake = -1;   /* end of faked up lines--don't free */
  69 static LINENUM  p_bfake = -1;   /* beg of faked up lines */
  70 static FILE     *pfp = NULL;    /* patch file pointer */
  71 static char     *bestguess = NULL;      /* guess at correct filename */
  72
  73 static void     grow_hunkmax(void);
  74 static int      intuit_diff_type(void);
  75 static void     next_intuit_at(off_t, LINENUM);
  76 static void     skip_to(off_t, LINENUM);
  77 static size_t   pgets(bool _do_indent);
  78 static char     *best_name(const struct file_name *, bool);
  79 static char     *posix_name(const struct file_name *, bool);
  80 static size_t   num_components(const char *);
  81 static LINENUM  strtolinenum(char *, char **);
  82
  83 /*
  84  * Prepare to look for the next patch in the patch file.
  85  */
  86 void
  87 re_patch(void)
  88 {
  89         p_first = 0;
  90         p_newfirst = 0;
  91         p_ptrn_lines = 0;
  92         p_repl_lines = 0;
  93         p_end = (LINENUM) - 1;
  94         p_max = 0;
  95         p_indent = 0;
  96 }
  97
  98 /*
  99  * Open the patch file at the beginning of time.
 100  */
 101 void
 102 open_patch_file(const char *filename)
 103 {
 104         struct stat filestat;
 105         int nr, nw;
 106
 107         if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
 108                 pfp = fopen(TMPPATNAME, "w");
 109                 if (pfp == NULL)
 110                         pfatal("can't create %s", TMPPATNAME);
 111                 while ((nr = fread(buf, 1, buf_size, stdin)) > 0) {
 112                         nw = fwrite(buf, 1, nr, pfp);
 113                         if (nr != nw)
 114                                 pfatal("write error to %s", TMPPATNAME);
 115                 }
 116                 if (ferror(pfp) || fclose(pfp))
 117                         pfatal("can't write %s", TMPPATNAME);
 118                 filename = TMPPATNAME;
 119         }
 120         pfp = fopen(filename, "r");
 121         if (pfp == NULL)
 122                 pfatal("patch file %s not found", filename);
 123         if (fstat(fileno(pfp), &filestat))
 124                 pfatal("can't stat %s", filename);
 125         p_filesize = filestat.st_size;
 126         next_intuit_at(0, 1L);  /* start at the beginning */
 127         set_hunkmax();
 128 }
 129
 130 /*
 131  * Make sure our dynamically realloced tables are malloced to begin with.
 132  */
 133 void
 134 set_hunkmax(void)
 135 {
 136         if (p_line == NULL)
 137                 p_line = malloc(hunkmax * sizeof(char *));
 138         if (p_len == NULL)
 139                 p_len = malloc(hunkmax * sizeof(unsigned short));
 140         if (p_char == NULL)
 141                 p_char = malloc(hunkmax * sizeof(char));
 142 }
 143
 144 /*
 145  * Enlarge the arrays containing the current hunk of patch.
 146  */
 147 static void
 148 grow_hunkmax(void)
 149 {
 150         int new_hunkmax = hunkmax * 2;
 151
 152         if (p_line == NULL || p_len == NULL || p_char == NULL)
 153                 fatal("Internal memory allocation error\n");
 154
 155         p_line = reallocf(p_line, new_hunkmax * sizeof(char *));
 156         p_len = reallocf(p_len, new_hunkmax * sizeof(unsigned short));
 157         p_char = reallocf(p_char, new_hunkmax * sizeof(char));
 158
 159         if (p_line != NULL && p_len != NULL && p_char != NULL) {
 160                 hunkmax = new_hunkmax;
 161                 return;
 162         }
 163
 164         if (!using_plan_a)
 165                 fatal("out of memory\n");
 166         out_of_mem = true;      /* whatever is null will be allocated again */
 167                                 /* from within plan_a(), of all places */
 168 }
 169
 170 /* True if the remainder of the patch file contains a diff of some sort. */
 171
 172 bool
 173 there_is_another_patch(void)
 174 {
 175         bool exists = false;
 176
 177         if (p_base != 0 && p_base >= p_filesize) {
 178                 if (verbose)
 179                         say("done\n");
 180                 return false;
 181         }
 182         if (verbose)
 183                 say("Hmm...");
 184         diff_type = intuit_diff_type();
 185         if (!diff_type) {
 186                 if (p_base != 0) {
 187                         if (verbose)
 188                                 say("  Ignoring the trailing garbage.\ndone\n");
 189                 } else
 190                         say("  I can't seem to find a patch in there anywhere.\n");
 191                 return false;
 192         }
 193         if (verbose)
 194                 say("  %sooks like %s to me...\n",
 195                     (p_base == 0 ? "L" : "The next patch l"),
 196                     diff_type == UNI_DIFF ? "a unified diff" :
 197                     diff_type == CONTEXT_DIFF ? "a context diff" :
 198                 diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
 199                     diff_type == NORMAL_DIFF ? "a normal diff" :
 200                     "an ed script");
 201         if (p_indent && verbose)
 202                 say("(Patch is indented %d space%s.)\n", p_indent,
 203                     p_indent == 1 ? "" : "s");
 204         skip_to(p_start, p_sline);
 205         while (filearg[0] == NULL) {
 206                 if (force || batch) {
 207                         say("No file to patch.  Skipping...\n");
 208                         filearg[0] = xstrdup(bestguess);
 209                         skip_rest_of_patch = true;
 210                         return true;
 211                 }
 212                 ask("File to patch: ");
 213                 if (*buf != '\n') {
 214                         free(bestguess);
 215                         bestguess = xstrdup(buf);
 216                         filearg[0] = fetchname(buf, &exists, 0);
 217                 }
 218                 if (!exists) {
 219                         int def_skip = *bestguess == '\0';
 220                         ask("No file found--skip this patch? [%c] ",
 221                             def_skip  ? 'y' : 'n');
 222                         if (*buf == 'n' || (!def_skip && *buf != 'y'))
 223                                 continue;
 224                         if (verbose)
 225                                 say("Skipping patch...\n");
 226                         free(filearg[0]);
 227                         filearg[0] = fetchname(bestguess, &exists, 0);
 228                         skip_rest_of_patch = true;
 229                         return true;
 230                 }
 231         }
 232         return true;
 233 }
 234
 235 static void
 236 p4_fetchname(struct file_name *name, char *str)
 237 {
 238         char *t, *h;
 239
 240         /* Skip leading whitespace. */
 241         while (isspace((unsigned char)*str))
 242                 str++;
 243
 244         /* Remove the file revision number. */
 245         for (t = str, h = NULL; *t != '\0' && !isspace((unsigned char)*t); t++)
 246                 if (*t == '#')
 247                         h = t;
 248         if (h != NULL)
 249                 *h = '\0';
 250
 251         name->path = fetchname(str, &name->exists, strippath);
 252 }
 253
 254 /* Determine what kind of diff is in the remaining part of the patch file. */
 255
 256 static int
 257 intuit_diff_type(void)
 258 {
 259         off_t   this_line = 0, previous_line;
 260         off_t   first_command_line = -1;
 261         LINENUM fcl_line = -1;
 262         bool    last_line_was_command = false, this_is_a_command = false;
 263         bool    stars_last_line = false, stars_this_line = false;
 264         char    *s, *t;
 265         int     indent, retval;
 266         struct file_name names[MAX_FILE];
 267
 268         memset(names, 0, sizeof(names));
 269         ok_to_create_file = false;
 270         fseeko(pfp, p_base, SEEK_SET);
 271         p_input_line = p_bline - 1;
 272         for (;;) {
 273                 previous_line = this_line;
 274                 last_line_was_command = this_is_a_command;
 275                 stars_last_line = stars_this_line;
 276                 this_line = ftello(pfp);
 277                 indent = 0;
 278                 p_input_line++;
 279                 if (pgets(false) == 0) {
 280                         if (first_command_line >= 0) {
 281                                 /* nothing but deletes!? */
 282                                 p_start = first_command_line;
 283                                 p_sline = fcl_line;
 284                                 retval = ED_DIFF;
 285                                 goto scan_exit;
 286                         } else {
 287                                 p_start = this_line;
 288                                 p_sline = p_input_line;
 289                                 retval = 0;
 290                                 goto scan_exit;
 291                         }
 292                 }
 293                 for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
 294                         if (*s == '\t')
 295                                 indent += 8 - (indent % 8);
 296                         else
 297                                 indent++;
 298                 }
 299                 for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
 300                         ;
 301                 this_is_a_command = (isdigit((unsigned char)*s) &&
 302                     (*t == 'd' || *t == 'c' || *t == 'a'));
 303                 if (first_command_line < 0 && this_is_a_command) {
 304                         first_command_line = this_line;
 305                         fcl_line = p_input_line;
 306                         p_indent = indent;      /* assume this for now */
 307                 }
 308                 if (!stars_last_line && strnEQ(s, "*** ", 4))
 309                         names[OLD_FILE].path = fetchname(s + 4,
 310                             &names[OLD_FILE].exists, strippath);
 311                 else if (strnEQ(s, "--- ", 4))
 312                         names[NEW_FILE].path = fetchname(s + 4,
 313                             &names[NEW_FILE].exists, strippath);
 314                 else if (strnEQ(s, "+++ ", 4))
 315                         /* pretend it is the old name */
 316                         names[OLD_FILE].path = fetchname(s + 4,
 317                             &names[OLD_FILE].exists, strippath);
 318                 else if (strnEQ(s, "Index:", 6))
 319                         names[INDEX_FILE].path = fetchname(s + 6,
 320                             &names[INDEX_FILE].exists, strippath);
 321                 else if (strnEQ(s, "Prereq:", 7)) {
 322                         for (t = s + 7; isspace((unsigned char)*t); t++)
 323                                 ;
 324                         revision = xstrdup(t);
 325                         for (t = revision;
 326                              *t && !isspace((unsigned char)*t); t++)
 327                                 ;
 328                         *t = '\0';
 329                         if (*revision == '\0') {
 330                                 free(revision);
 331                                 revision = NULL;
 332                         }
 333                 } else if (strnEQ(s, "==== ", 5)) {
 334                         /* Perforce-style diffs. */
 335                         if ((t = strstr(s + 5, " - ")) != NULL)
 336                                 p4_fetchname(&names[NEW_FILE], t + 3);
 337                         p4_fetchname(&names[OLD_FILE], s + 5);
 338                 }
 339                 if ((!diff_type || diff_type == ED_DIFF) &&
 340                     first_command_line >= 0 &&
 341                     strEQ(s, ".\n")) {
 342                         p_indent = indent;
 343                         p_start = first_command_line;
 344                         p_sline = fcl_line;
 345                         retval = ED_DIFF;
 346                         goto scan_exit;
 347                 }
 348                 if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
 349                         if (strnEQ(s + 4, "0,0", 3))
 350                                 ok_to_create_file = true;
 351                         p_indent = indent;
 352                         p_start = this_line;
 353                         p_sline = p_input_line;
 354                         retval = UNI_DIFF;
 355                         goto scan_exit;
 356                 }
 357                 stars_this_line = strnEQ(s, "********", 8);
 358                 if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
 359                     strnEQ(s, "*** ", 4)) {
 360                         if (strtolinenum(s + 4, &s) == 0)
 361                                 ok_to_create_file = true;
 362                         /*
 363                          * If this is a new context diff the character just
 364                          * at the end of the line is a '*'.
 365                          */
 366                         while (*s && *s != '\n')
 367                                 s++;
 368                         p_indent = indent;
 369                         p_start = previous_line;
 370                         p_sline = p_input_line - 1;
 371                         retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
 372                         goto scan_exit;
 373                 }
 374                 if ((!diff_type || diff_type == NORMAL_DIFF) &&
 375                     last_line_was_command &&
 376                     (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
 377                         p_start = previous_line;
 378                         p_sline = p_input_line - 1;
 379                         p_indent = indent;
 380                         retval = NORMAL_DIFF;
 381                         goto scan_exit;
 382                 }
 383         }
 384 scan_exit:
 385         if (retval == UNI_DIFF) {
 386                 /* unswap old and new */
 387                 struct file_name tmp = names[OLD_FILE];
 388                 names[OLD_FILE] = names[NEW_FILE];
 389                 names[NEW_FILE] = tmp;
 390         }
 391         if (filearg[0] == NULL) {
 392                 if (posix)
 393                         filearg[0] = posix_name(names, ok_to_create_file);
 394                 else {
 395                         /* Ignore the Index: name for context diffs, like GNU */
 396                         if (names[OLD_FILE].path != NULL ||
 397                             names[NEW_FILE].path != NULL) {
 398                                 free(names[INDEX_FILE].path);
 399                                 names[INDEX_FILE].path = NULL;
 400                         }
 401                         filearg[0] = best_name(names, ok_to_create_file);
 402                 }
 403         }
 404
 405         free(bestguess);
 406         bestguess = NULL;
 407         if (filearg[0] != NULL)
 408                 bestguess = xstrdup(filearg[0]);
 409         else if (!ok_to_create_file) {
 410                 /*
 411                  * We don't want to create a new file but we need a
 412                  * filename to set bestguess.  Avoid setting filearg[0]
 413                  * so the file is not created automatically.
 414                  */
 415                 if (posix)
 416                         bestguess = posix_name(names, true);
 417                 else
 418                         bestguess = best_name(names, true);
 419         }
 420         free(names[OLD_FILE].path);
 421         free(names[NEW_FILE].path);
 422         free(names[INDEX_FILE].path);
 423         return retval;
 424 }
 425
 426 /*
 427  * Remember where this patch ends so we know where to start up again.
 428  */
 429 static void
 430 next_intuit_at(off_t file_pos, LINENUM file_line)
 431 {
 432         p_base = file_pos;
 433         p_bline = file_line;
 434 }
 435
 436 /*
 437  * Basically a verbose fseeko() to the actual diff listing.
 438  */
 439 static void
 440 skip_to(off_t file_pos, LINENUM file_line)
 441 {
 442         size_t  len;
 443
 444         if (p_base > file_pos)
 445                 fatal("Internal error: seek %lld>%lld\n",
 446                    (long long)p_base, (long long)file_pos);
 447         if (verbose && p_base < file_pos) {
 448                 fseeko(pfp, p_base, SEEK_SET);
 449                 say("The text leading up to this was:\n--------------------------\n");
 450                 while (ftello(pfp) < file_pos) {
 451                         len = pgets(false);
 452                         if (len == 0)
 453                                 fatal("Unexpected end of file\n");
 454                         say("|%s", buf);
 455                 }
 456                 say("--------------------------\n");
 457         } else
 458                 fseeko(pfp, file_pos, SEEK_SET);
 459         p_input_line = file_line - 1;
 460 }
 461
 462 /* Make this a function for better debugging.  */
 463 static void
 464 malformed(void)
 465 {
 466         fatal("malformed patch at line %ld: %s", p_input_line, buf);
 467         /* about as informative as "Syntax error" in C */
 468 }
 469
 470 /*
 471  * True if the line has been discarded (i.e. it is a line saying
 472  *  "\ No newline at end of file".)
 473  */
 474 static bool
 475 remove_special_line(void)
 476 {
 477         int     c;
 478
 479         c = fgetc(pfp);
 480         if (c == '\\') {
 481                 do {
 482                         c = fgetc(pfp);
 483                 } while (c != EOF && c != '\n');
 484
 485                 return true;
 486         }
 487         if (c != EOF)
 488                 fseeko(pfp, -1, SEEK_CUR);
 489
 490         return false;
 491 }
 492
 493 /*
 494  * True if there is more of the current diff listing to process.
 495  */
 496 bool
 497 another_hunk(void)
 498 {
 499         off_t   line_beginning;                 /* file pos of the current line */
 500         LINENUM repl_beginning;                 /* index of --- line */
 501         LINENUM fillcnt;                        /* #lines of missing ptrn or repl */
 502         LINENUM fillsrc;                        /* index of first line to copy */
 503         LINENUM filldst;                        /* index of first missing line */
 504         bool    ptrn_spaces_eaten;              /* ptrn was slightly malformed */
 505         bool    repl_could_be_missing;          /* no + or ! lines in this hunk */
 506         bool    repl_missing;                   /* we are now backtracking */
 507         off_t   repl_backtrack_position;        /* file pos of first repl line */
 508         LINENUM repl_patch_line;                /* input line number for same */
 509         LINENUM ptrn_copiable;                  /* # of copiable lines in ptrn */
 510         char    *s;
 511         size_t  len;
 512         int     context = 0;
 513
 514         while (p_end >= 0) {
 515                 if (p_end == p_efake)
 516                         p_end = p_bfake;        /* don't free twice */
 517                 else
 518                         free(p_line[p_end]);
 519                 p_end--;
 520         }
 521         p_efake = -1;
 522
 523         p_max = hunkmax;        /* gets reduced when --- found */
 524         if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
 525                 line_beginning = ftello(pfp);
 526                 repl_beginning = 0;
 527                 fillcnt = 0;
 528                 fillsrc = 0;
 529                 filldst = 0;
 530                 ptrn_spaces_eaten = false;
 531                 repl_could_be_missing = true;
 532                 repl_missing = false;
 533                 repl_backtrack_position = 0;
 534                 repl_patch_line = 0;
 535                 ptrn_copiable = 0;
 536
 537                 len = pgets(true);
 538                 p_input_line++;
 539                 if (len == 0 || strnNE(buf, "********", 8)) {
 540                         next_intuit_at(line_beginning, p_input_line);
 541                         return false;
 542                 }
 543                 p_context = 100;
 544                 p_hunk_beg = p_input_line + 1;
 545                 while (p_end < p_max) {
 546                         line_beginning = ftello(pfp);
 547                         len = pgets(true);
 548                         p_input_line++;
 549                         if (len == 0) {
 550                                 if (p_max - p_end < 4) {
 551                                         /* assume blank lines got chopped */
 552                                         strlcpy(buf, "  \n", buf_size);
 553                                 } else {
 554                                         if (repl_beginning && repl_could_be_missing) {
 555                                                 repl_missing = true;
 556                                                 goto hunk_done;
 557                                         }
 558                                         fatal("unexpected end of file in patch\n");
 559                                 }
 560                         }
 561                         p_end++;
 562                         if (p_end >= hunkmax)
 563                                 fatal("Internal error: hunk larger than hunk "
 564                                     "buffer size");
 565                         p_char[p_end] = *buf;
 566                         p_line[p_end] = NULL;
 567                         switch (*buf) {
 568                         case '*':
 569                                 if (strnEQ(buf, "********", 8)) {
 570                                         if (repl_beginning && repl_could_be_missing) {
 571                                                 repl_missing = true;
 572                                                 goto hunk_done;
 573                                         } else
 574                                                 fatal("unexpected end of hunk "
 575                                                     "at line %ld\n",
 576                                                     p_input_line);
 577                                 }
 578                                 if (p_end != 0) {
 579                                         if (repl_beginning && repl_could_be_missing) {
 580                                                 repl_missing = true;
 581                                                 goto hunk_done;
 582                                         }
 583                                         fatal("unexpected *** at line %ld: %s",
 584                                             p_input_line, buf);
 585                                 }
 586                                 context = 0;
 587                                 p_line[p_end] = savestr(buf);
 588                                 if (out_of_mem) {
 589                                         p_end--;
 590                                         return false;
 591                                 }
 592                                 for (s = buf;
 593                                      *s && !isdigit((unsigned char)*s); s++)
 594                                         ;
 595                                 if (!*s)
 596                                         malformed();
 597                                 if (strnEQ(s, "0,0", 3))
 598                                         memmove(s, s + 2, strlen(s + 2) + 1);
 599                                 p_first = strtolinenum(s, &s);
 600                                 if (*s == ',') {
 601                                         for (;
 602                                              *s && !isdigit((unsigned char)*s); s++)
 603                                                 ;
 604                                         if (!*s)
 605                                                 malformed();
 606                                         p_ptrn_lines = strtolinenum(s, &s) - p_first + 1;
 607                                         if (p_ptrn_lines < 0)
 608                                                 malformed();
 609                                 } else if (p_first)
 610                                         p_ptrn_lines = 1;
 611                                 else {
 612                                         p_ptrn_lines = 0;
 613                                         p_first = 1;
 614                                 }
 615                                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 616                                     p_ptrn_lines >= LINENUM_MAX - 6)
 617                                         malformed();
 618
 619                                 /* we need this much at least */
 620                                 p_max = p_ptrn_lines + 6;
 621                                 while (p_max >= hunkmax)
 622                                         grow_hunkmax();
 623                                 p_max = hunkmax;
 624                                 break;
 625                         case '-':
 626                                 if (buf[1] == '-') {
 627                                         if (repl_beginning ||
 628                                             (p_end != p_ptrn_lines + 1 +
 629                                             (p_char[p_end - 1] == '\n'))) {
 630                                                 if (p_end == 1) {
 631                                                         /*
 632                                                          * `old' lines were omitted;
 633                                                          * set up to fill them in
 634                                                          * from 'new' context lines.
 635                                                          */
 636                                                         p_end = p_ptrn_lines + 1;
 637                                                         fillsrc = p_end + 1;
 638                                                         filldst = 1;
 639                                                         fillcnt = p_ptrn_lines;
 640                                                 } else {
 641                                                         if (repl_beginning) {
 642                                                                 if (repl_could_be_missing) {
 643                                                                         repl_missing = true;
 644                                                                         goto hunk_done;
 645                                                                 }
 646                                                                 fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
 647                                                                     p_input_line, p_hunk_beg + repl_beginning);
 648                                                         } else {
 649                                                                 fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
 650                                                                     (p_end <= p_ptrn_lines
 651                                                                     ? "Premature"
 652                                                                     : "Overdue"),
 653                                                                     p_input_line, p_hunk_beg);
 654                                                         }
 655                                                 }
 656                                         }
 657                                         repl_beginning = p_end;
 658                                         repl_backtrack_position = ftello(pfp);
 659                                         repl_patch_line = p_input_line;
 660                                         p_line[p_end] = savestr(buf);
 661                                         if (out_of_mem) {
 662                                                 p_end--;
 663                                                 return false;
 664                                         }
 665                                         p_char[p_end] = '=';
 666                                         for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 667                                                 ;
 668                                         if (!*s)
 669                                                 malformed();
 670                                         p_newfirst = strtolinenum(s, &s);
 671                                         if (*s == ',') {
 672                                                 for (; *s && !isdigit((unsigned char)*s); s++)
 673                                                         ;
 674                                                 if (!*s)
 675                                                         malformed();
 676                                                 p_repl_lines = strtolinenum(s, &s) -
 677                                                     p_newfirst + 1;
 678                                                 if (p_repl_lines < 0)
 679                                                         malformed();
 680                                         } else if (p_newfirst)
 681                                                 p_repl_lines = 1;
 682                                         else {
 683                                                 p_repl_lines = 0;
 684                                                 p_newfirst = 1;
 685                                         }
 686                                         if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
 687                                             p_repl_lines >= LINENUM_MAX - p_end)
 688                                                 malformed();
 689                                         p_max = p_repl_lines + p_end;
 690                                         if (p_max > MAXHUNKSIZE)
 691                                                 fatal("hunk too large (%ld lines) at line %ld: %s",
 692                                                     p_max, p_input_line, buf);
 693                                         while (p_max >= hunkmax)
 694                                                 grow_hunkmax();
 695                                         if (p_repl_lines != ptrn_copiable &&
 696                                             (p_context != 0 || p_repl_lines != 1))
 697                                                 repl_could_be_missing = false;
 698                                         break;
 699                                 }
 700                                 goto change_line;
 701                         case '+':
 702                         case '!':
 703                                 repl_could_be_missing = false;
 704                 change_line:
 705                                 if (buf[1] == '\n' && canonicalize)
 706                                         strlcpy(buf + 1, " \n", buf_size - 1);
 707                                 if (!isspace((unsigned char)buf[1]) &&
 708                                     buf[1] != '>' && buf[1] != '<' &&
 709                                     repl_beginning && repl_could_be_missing) {
 710                                         repl_missing = true;
 711                                         goto hunk_done;
 712                                 }
 713                                 if (context >= 0) {
 714                                         if (context < p_context)
 715                                                 p_context = context;
 716                                         context = -1000;
 717                                 }
 718                                 p_line[p_end] = savestr(buf + 2);
 719                                 if (out_of_mem) {
 720                                         p_end--;
 721                                         return false;
 722                                 }
 723                                 if (p_end == p_ptrn_lines) {
 724                                         if (remove_special_line()) {
 725                                                 int     l;
 726
 727                                                 l = strlen(p_line[p_end]) - 1;
 728                                                 (p_line[p_end])[l] = 0;
 729                                         }
 730                                 }
 731                                 break;
 732                         case '\t':
 733                         case '\n':      /* assume the 2 spaces got eaten */
 734                                 if (repl_beginning && repl_could_be_missing &&
 735                                     (!ptrn_spaces_eaten ||
 736                                     diff_type == NEW_CONTEXT_DIFF)) {
 737                                         repl_missing = true;
 738                                         goto hunk_done;
 739                                 }
 740                                 p_line[p_end] = savestr(buf);
 741                                 if (out_of_mem) {
 742                                         p_end--;
 743                                         return false;
 744                                 }
 745                                 if (p_end != p_ptrn_lines + 1) {
 746                                         ptrn_spaces_eaten |= (repl_beginning != 0);
 747                                         context++;
 748                                         if (!repl_beginning)
 749                                                 ptrn_copiable++;
 750                                         p_char[p_end] = ' ';
 751                                 }
 752                                 break;
 753                         case ' ':
 754                                 if (!isspace((unsigned char)buf[1]) &&
 755                                     repl_beginning && repl_could_be_missing) {
 756                                         repl_missing = true;
 757                                         goto hunk_done;
 758                                 }
 759                                 context++;
 760                                 if (!repl_beginning)
 761                                         ptrn_copiable++;
 762                                 p_line[p_end] = savestr(buf + 2);
 763                                 if (out_of_mem) {
 764                                         p_end--;
 765                                         return false;
 766                                 }
 767                                 break;
 768                         default:
 769                                 if (repl_beginning && repl_could_be_missing) {
 770                                         repl_missing = true;
 771                                         goto hunk_done;
 772                                 }
 773                                 malformed();
 774                         }
 775                         /* set up p_len for strncmp() so we don't have to */
 776                         /* assume null termination */
 777                         if (p_line[p_end])
 778                                 p_len[p_end] = strlen(p_line[p_end]);
 779                         else
 780                                 p_len[p_end] = 0;
 781                 }
 782
 783 hunk_done:
 784                 if (p_end >= 0 && !repl_beginning)
 785                         fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
 786
 787                 if (repl_missing) {
 788
 789                         /* reset state back to just after --- */
 790                         p_input_line = repl_patch_line;
 791                         for (p_end--; p_end > repl_beginning; p_end--)
 792                                 free(p_line[p_end]);
 793                         fseeko(pfp, repl_backtrack_position, SEEK_SET);
 794
 795                         /* redundant 'new' context lines were omitted - set */
 796                         /* up to fill them in from the old file context */
 797                         if (!p_context && p_repl_lines == 1) {
 798                                 p_repl_lines = 0;
 799                                 p_max--;
 800                         }
 801                         fillsrc = 1;
 802                         filldst = repl_beginning + 1;
 803                         fillcnt = p_repl_lines;
 804                         p_end = p_max;
 805                 } else if (!p_context && fillcnt == 1) {
 806                         /* the first hunk was a null hunk with no context */
 807                         /* and we were expecting one line -- fix it up. */
 808                         while (filldst < p_end) {
 809                                 p_line[filldst] = p_line[filldst + 1];
 810                                 p_char[filldst] = p_char[filldst + 1];
 811                                 p_len[filldst] = p_len[filldst + 1];
 812                                 filldst++;
 813                         }
 814 #if 0
 815                         repl_beginning--;       /* this doesn't need to be fixed */
 816 #endif
 817                         p_end--;
 818                         p_first++;      /* do append rather than insert */
 819                         fillcnt = 0;
 820                         p_ptrn_lines = 0;
 821                 }
 822                 if (diff_type == CONTEXT_DIFF &&
 823                     (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
 824                         if (verbose)
 825                                 say("%s\n%s\n%s\n",
 826                                     "(Fascinating--this is really a new-style context diff but without",
 827                                     "the telltale extra asterisks on the *** line that usually indicate",
 828                                     "the new style...)");
 829                         diff_type = NEW_CONTEXT_DIFF;
 830                 }
 831                 /* if there were omitted context lines, fill them in now */
 832                 if (fillcnt) {
 833                         p_bfake = filldst;      /* remember where not to free() */
 834                         p_efake = filldst + fillcnt - 1;
 835                         while (fillcnt-- > 0) {
 836                                 while (fillsrc <= p_end && p_char[fillsrc] != ' ')
 837                                         fillsrc++;
 838                                 if (fillsrc > p_end)
 839                                         fatal("replacement text or line numbers mangled in hunk at line %ld\n",
 840                                             p_hunk_beg);
 841                                 p_line[filldst] = p_line[fillsrc];
 842                                 p_char[filldst] = p_char[fillsrc];
 843                                 p_len[filldst] = p_len[fillsrc];
 844                                 fillsrc++;
 845                                 filldst++;
 846                         }
 847                         while (fillsrc <= p_end && fillsrc != repl_beginning &&
 848                             p_char[fillsrc] != ' ')
 849                                 fillsrc++;
 850 #ifdef DEBUGGING
 851                         if (debug & 64)
 852                                 printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
 853                                 fillsrc, filldst, repl_beginning, p_end + 1);
 854 #endif
 855                         if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
 856                                 malformed();
 857                         if (filldst != p_end + 1 && filldst != repl_beginning)
 858                                 malformed();
 859                 }
 860                 if (p_line[p_end] != NULL) {
 861                         if (remove_special_line()) {
 862                                 p_len[p_end] -= 1;
 863                                 (p_line[p_end])[p_len[p_end]] = 0;
 864                         }
 865                 }
 866         } else if (diff_type == UNI_DIFF) {
 867                 LINENUM fillold;        /* index of old lines */
 868                 LINENUM fillnew;        /* index of new lines */
 869                 char    ch;
 870
 871                 line_beginning = ftello(pfp); /* file pos of the current line */
 872                 len = pgets(true);
 873                 p_input_line++;
 874                 if (len == 0 || strnNE(buf, "@@ -", 4)) {
 875                         next_intuit_at(line_beginning, p_input_line);
 876                         return false;
 877                 }
 878                 s = buf + 4;
 879                 if (!*s)
 880                         malformed();
 881                 p_first = strtolinenum(s, &s);
 882                 if (*s == ',') {
 883                         p_ptrn_lines = strtolinenum(s + 1, &s);
 884                 } else
 885                         p_ptrn_lines = 1;
 886                 if (*s == ' ')
 887                         s++;
 888                 if (*s != '+' || !*++s)
 889                         malformed();
 890                 p_newfirst = strtolinenum(s, &s);
 891                 if (*s == ',') {
 892                         p_repl_lines = strtolinenum(s + 1, &s);
 893                 } else
 894                         p_repl_lines = 1;
 895                 if (*s == ' ')
 896                         s++;
 897                 if (*s != '@')
 898                         malformed();
 899                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 900                     p_newfirst > LINENUM_MAX - p_repl_lines ||
 901                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
 902                         malformed();
 903                 if (!p_ptrn_lines)
 904                         p_first++;      /* do append rather than insert */
 905                 p_max = p_ptrn_lines + p_repl_lines + 1;
 906                 while (p_max >= hunkmax)
 907                         grow_hunkmax();
 908                 fillold = 1;
 909                 fillnew = fillold + p_ptrn_lines;
 910                 p_end = fillnew + p_repl_lines;
 911                 snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
 912                     p_first + p_ptrn_lines - 1);
 913                 p_line[0] = savestr(buf);
 914                 if (out_of_mem) {
 915                         p_end = -1;
 916                         return false;
 917                 }
 918                 p_char[0] = '*';
 919                 snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
 920                     p_newfirst + p_repl_lines - 1);
 921                 p_line[fillnew] = savestr(buf);
 922                 if (out_of_mem) {
 923                         p_end = 0;
 924                         return false;
 925                 }
 926                 p_char[fillnew++] = '=';
 927                 p_context = 100;
 928                 context = 0;
 929                 p_hunk_beg = p_input_line + 1;
 930                 while (fillold <= p_ptrn_lines || fillnew <= p_end) {
 931                         line_beginning = ftello(pfp);
 932                         len = pgets(true);
 933                         p_input_line++;
 934                         if (len == 0) {
 935                                 if (p_max - fillnew < 3) {
 936                                         /* assume blank lines got chopped */
 937                                         strlcpy(buf, " \n", buf_size);
 938                                 } else {
 939                                         fatal("unexpected end of file in patch\n");
 940                                 }
 941                         }
 942                         if (*buf == '\t' || *buf == '\n') {
 943                                 ch = ' ';       /* assume the space got eaten */
 944                                 s = savestr(buf);
 945                         } else {
 946                                 ch = *buf;
 947                                 s = savestr(buf + 1);
 948                         }
 949                         if (out_of_mem) {
 950                                 while (--fillnew > p_ptrn_lines)
 951                                         free(p_line[fillnew]);
 952                                 p_end = fillold - 1;
 953                                 return false;
 954                         }
 955                         switch (ch) {
 956                         case '-':
 957                                 if (fillold > p_ptrn_lines) {
 958                                         free(s);
 959                                         p_end = fillnew - 1;
 960                                         malformed();
 961                                 }
 962                                 p_char[fillold] = ch;
 963                                 p_line[fillold] = s;
 964                                 p_len[fillold++] = strlen(s);
 965                                 if (fillold > p_ptrn_lines) {
 966                                         if (remove_special_line()) {
 967                                                 p_len[fillold - 1] -= 1;
 968                                                 s[p_len[fillold - 1]] = 0;
 969                                         }
 970                                 }
 971                                 break;
 972                         case '=':
 973                                 ch = ' ';
 974                                 /* FALL THROUGH */
 975                         case ' ':
 976                                 if (fillold > p_ptrn_lines) {
 977                                         free(s);
 978                                         while (--fillnew > p_ptrn_lines)
 979                                                 free(p_line[fillnew]);
 980                                         p_end = fillold - 1;
 981                                         malformed();
 982                                 }
 983                                 context++;
 984                                 p_char[fillold] = ch;
 985                                 p_line[fillold] = s;
 986                                 p_len[fillold++] = strlen(s);
 987                                 s = savestr(s);
 988                                 if (out_of_mem) {
 989                                         while (--fillnew > p_ptrn_lines)
 990                                                 free(p_line[fillnew]);
 991                                         p_end = fillold - 1;
 992                                         return false;
 993                                 }
 994                                 if (fillold > p_ptrn_lines) {
 995                                         if (remove_special_line()) {
 996                                                 p_len[fillold - 1] -= 1;
 997                                                 s[p_len[fillold - 1]] = 0;
 998                                         }
 999                                 }
1000                                 /* FALL THROUGH */
1001                         case '+':
1002                                 if (fillnew > p_end) {
1003                                         free(s);
1004                                         while (--fillnew > p_ptrn_lines)
1005                                                 free(p_line[fillnew]);
1006                                         p_end = fillold - 1;
1007                                         malformed();
1008                                 }
1009                                 p_char[fillnew] = ch;
1010                                 p_line[fillnew] = s;
1011                                 p_len[fillnew++] = strlen(s);
1012                                 if (fillold > p_ptrn_lines) {
1013                                         if (remove_special_line()) {
1014                                                 p_len[fillnew - 1] -= 1;
1015                                                 s[p_len[fillnew - 1]] = 0;
1016                                         }
1017                                 }
1018                                 break;
1019                         default:
1020                                 p_end = fillnew;
1021                                 malformed();
1022                         }
1023                         if (ch != ' ' && context > 0) {
1024                                 if (context < p_context)
1025                                         p_context = context;
1026                                 context = -1000;
1027                         }
1028                 }               /* while */
1029         } else {                /* normal diff--fake it up */
1030                 char    hunk_type;
1031                 int     i;
1032                 LINENUM min, max;
1033
1034                 line_beginning = ftello(pfp);
1035                 p_context = 0;
1036                 len = pgets(true);
1037                 p_input_line++;
1038                 if (len == 0 || !isdigit((unsigned char)*buf)) {
1039                         next_intuit_at(line_beginning, p_input_line);
1040                         return false;
1041                 }
1042                 p_first = strtolinenum(buf, &s);
1043                 if (*s == ',') {
1044                         p_ptrn_lines = strtolinenum(s + 1, &s) - p_first + 1;
1045                         if (p_ptrn_lines < 0)
1046                                 malformed();
1047                 } else
1048                         p_ptrn_lines = (*s != 'a');
1049                 hunk_type = *s;
1050                 if (hunk_type == 'a')
1051                         p_first++;      /* do append rather than insert */
1052                 min = strtolinenum(s + 1, &s);
1053                 if (*s == ',')
1054                         max = strtolinenum(s + 1, &s);
1055                 else
1056                         max = min;
1057                 if (min < 0 || min > max || max - min == LINENUM_MAX)
1058                         malformed();
1059                 if (hunk_type == 'd')
1060                         min++;
1061                 p_newfirst = min;
1062                 p_repl_lines = max - min + 1;
1063                 if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1064                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1065                         malformed();
1066                 p_end = p_ptrn_lines + p_repl_lines + 1;
1067                 if (p_end > MAXHUNKSIZE)
1068                         fatal("hunk too large (%ld lines) at line %ld: %s",
1069                             p_end, p_input_line, buf);
1070                 while (p_end >= hunkmax)
1071                         grow_hunkmax();
1072                 snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1073                     p_first + p_ptrn_lines - 1);
1074                 p_line[0] = savestr(buf);
1075                 if (out_of_mem) {
1076                         p_end = -1;
1077                         return false;
1078                 }
1079                 p_char[0] = '*';
1080                 for (i = 1; i <= p_ptrn_lines; i++) {
1081                         len = pgets(true);
1082                         p_input_line++;
1083                         if (len == 0)
1084                                 fatal("unexpected end of file in patch at line %ld\n",
1085                                     p_input_line);
1086                         if (*buf != '<')
1087                                 fatal("< expected at line %ld of patch\n",
1088                                     p_input_line);
1089                         p_line[i] = savestr(buf + 2);
1090                         if (out_of_mem) {
1091                                 p_end = i - 1;
1092                                 return false;
1093                         }
1094                         p_len[i] = strlen(p_line[i]);
1095                         p_char[i] = '-';
1096                 }
1097
1098                 if (remove_special_line()) {
1099                         p_len[i - 1] -= 1;
1100                         (p_line[i - 1])[p_len[i - 1]] = 0;
1101                 }
1102                 if (hunk_type == 'c') {
1103                         len = pgets(true);
1104                         p_input_line++;
1105                         if (len == 0)
1106                                 fatal("unexpected end of file in patch at line %ld\n",
1107                                     p_input_line);
1108                         if (*buf != '-')
1109                                 fatal("--- expected at line %ld of patch\n",
1110                                     p_input_line);
1111                 }
1112                 snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1113                 p_line[i] = savestr(buf);
1114                 if (out_of_mem) {
1115                         p_end = i - 1;
1116                         return false;
1117                 }
1118                 p_char[i] = '=';
1119                 for (i++; i <= p_end; i++) {
1120                         len = pgets(true);
1121                         p_input_line++;
1122                         if (len == 0)
1123                                 fatal("unexpected end of file in patch at line %ld\n",
1124                                     p_input_line);
1125                         if (*buf != '>')
1126                                 fatal("> expected at line %ld of patch\n",
1127                                     p_input_line);
1128                         p_line[i] = savestr(buf + 2);
1129                         if (out_of_mem) {
1130                                 p_end = i - 1;
1131                                 return false;
1132                         }
1133                         p_len[i] = strlen(p_line[i]);
1134                         p_char[i] = '+';
1135                 }
1136
1137                 if (remove_special_line()) {
1138                         p_len[i - 1] -= 1;
1139                         (p_line[i - 1])[p_len[i - 1]] = 0;
1140                 }
1141         }
1142         if (reverse)            /* backwards patch? */
1143                 if (!pch_swap())
1144                         say("Not enough memory to swap next hunk!\n");
1145 #ifdef DEBUGGING
1146         if (debug & 2) {
1147                 LINENUM i;
1148                 char    special;
1149
1150                 for (i = 0; i <= p_end; i++) {
1151                         if (i == p_ptrn_lines)
1152                                 special = '^';
1153                         else
1154                                 special = ' ';
1155                         fprintf(stderr, "%3ld %c %c %s", i, p_char[i],
1156                             special, p_line[i]);
1157                         fflush(stderr);
1158                 }
1159         }
1160 #endif
1161         if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1162                 p_char[p_end + 1] = '^';        /* add a stopper for apply_hunk */
1163         return true;
1164 }
1165
1166 /*
1167  * Input a line from the patch file.
1168  * Worry about indentation if do_indent is true.
1169  * The line is read directly into the buf global variable which
1170  * is resized if necessary in order to hold the complete line.
1171  * Returns the number of characters read including the terminating
1172  * '\n', if any.
1173  */
1174 size_t
1175 pgets(bool do_indent)
1176 {
1177         char *line;
1178         size_t len;
1179         int indent = 0, skipped = 0;
1180
1181         line = fgetln(pfp, &len);
1182         if (line != NULL) {
1183                 if (len + 1 > buf_size) {
1184                         while (len + 1 > buf_size)
1185                                 buf_size *= 2;
1186                         free(buf);
1187                         buf = malloc(buf_size);
1188                         if (buf == NULL)
1189                                 fatal("out of memory\n");
1190                 }
1191                 if (do_indent == 1 && p_indent) {
1192                         for (;
1193                             indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1194                             line++, skipped++) {
1195                                 if (*line == '\t')
1196                                         indent += 8 - (indent %7);
1197                                 else
1198                                         indent++;
1199                         }
1200                 }
1201                 memcpy(buf, line, len - skipped);
1202                 buf[len - skipped] = '\0';
1203         }
1204         return len;
1205 }
1206
1207
1208 /*
1209  * Reverse the old and new portions of the current hunk.
1210  */
1211 bool
1212 pch_swap(void)
1213 {
1214         char    **tp_line;      /* the text of the hunk */
1215         unsigned short  *tp_len;/* length of each line */
1216         char    *tp_char;       /* +, -, and ! */
1217         LINENUM i;
1218         LINENUM n;
1219         bool    blankline = false;
1220         char    *s;
1221
1222         i = p_first;
1223         p_first = p_newfirst;
1224         p_newfirst = i;
1225
1226         /* make a scratch copy */
1227
1228         tp_line = p_line;
1229         tp_len = p_len;
1230         tp_char = p_char;
1231         p_line = NULL;  /* force set_hunkmax to allocate again */
1232         p_len = NULL;
1233         p_char = NULL;
1234         set_hunkmax();
1235         if (p_line == NULL || p_len == NULL || p_char == NULL) {
1236
1237                 free(p_line);
1238                 p_line = tp_line;
1239                 free(p_len);
1240                 p_len = tp_len;
1241                 free(p_char);
1242                 p_char = tp_char;
1243                 return false;   /* not enough memory to swap hunk! */
1244         }
1245         /* now turn the new into the old */
1246
1247         i = p_ptrn_lines + 1;
1248         if (tp_char[i] == '\n') {       /* account for possible blank line */
1249                 blankline = true;
1250                 i++;
1251         }
1252         if (p_efake >= 0) {     /* fix non-freeable ptr range */
1253                 if (p_efake <= i)
1254                         n = p_end - i + 1;
1255                 else
1256                         n = -i;
1257                 p_efake += n;
1258                 p_bfake += n;
1259         }
1260         for (n = 0; i <= p_end; i++, n++) {
1261                 p_line[n] = tp_line[i];
1262                 p_char[n] = tp_char[i];
1263                 if (p_char[n] == '+')
1264                         p_char[n] = '-';
1265                 p_len[n] = tp_len[i];
1266         }
1267         if (blankline) {
1268                 i = p_ptrn_lines + 1;
1269                 p_line[n] = tp_line[i];
1270                 p_char[n] = tp_char[i];
1271                 p_len[n] = tp_len[i];
1272                 n++;
1273         }
1274         if (p_char[0] != '=')
1275                 fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1276                     p_input_line, p_char[0]);
1277         p_char[0] = '*';
1278         for (s = p_line[0]; *s; s++)
1279                 if (*s == '-')
1280                         *s = '*';
1281
1282         /* now turn the old into the new */
1283
1284         if (p_char[0] != '*')
1285                 fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1286                     p_input_line, p_char[0]);
1287         tp_char[0] = '=';
1288         for (s = tp_line[0]; *s; s++)
1289                 if (*s == '*')
1290                         *s = '-';
1291         for (i = 0; n <= p_end; i++, n++) {
1292                 p_line[n] = tp_line[i];
1293                 p_char[n] = tp_char[i];
1294                 if (p_char[n] == '-')
1295                         p_char[n] = '+';
1296                 p_len[n] = tp_len[i];
1297         }
1298
1299         if (i != p_ptrn_lines + 1)
1300                 fatal("Malformed patch at line %ld: expected %ld lines, "
1301                     "got %ld\n",
1302                     p_input_line, p_ptrn_lines + 1, i);
1303
1304         i = p_ptrn_lines;
1305         p_ptrn_lines = p_repl_lines;
1306         p_repl_lines = i;
1307
1308         free(tp_line);
1309         free(tp_len);
1310         free(tp_char);
1311
1312         return true;
1313 }
1314
1315 /*
1316  * Return the specified line position in the old file of the old context.
1317  */
1318 LINENUM
1319 pch_first(void)
1320 {
1321         return p_first;
1322 }
1323
1324 /*
1325  * Return the number of lines of old context.
1326  */
1327 LINENUM
1328 pch_ptrn_lines(void)
1329 {
1330         return p_ptrn_lines;
1331 }
1332
1333 /*
1334  * Return the probable line position in the new file of the first line.
1335  */
1336 LINENUM
1337 pch_newfirst(void)
1338 {
1339         return p_newfirst;
1340 }
1341
1342 /*
1343  * Return the number of lines in the replacement text including context.
1344  */
1345 LINENUM
1346 pch_repl_lines(void)
1347 {
1348         return p_repl_lines;
1349 }
1350
1351 /*
1352  * Return the number of lines in the whole hunk.
1353  */
1354 LINENUM
1355 pch_end(void)
1356 {
1357         return p_end;
1358 }
1359
1360 /*
1361  * Return the number of context lines before the first changed line.
1362  */
1363 LINENUM
1364 pch_context(void)
1365 {
1366         return p_context;
1367 }
1368
1369 /*
1370  * Return the length of a particular patch line.
1371  */
1372 unsigned short
1373 pch_line_len(LINENUM line)
1374 {
1375         return p_len[line];
1376 }
1377
1378 /*
1379  * Return the control character (+, -, *, !, etc) for a patch line.
1380  */
1381 char
1382 pch_char(LINENUM line)
1383 {
1384         return p_char[line];
1385 }
1386
1387 /*
1388  * Return a pointer to a particular patch line.
1389  */
1390 char *
1391 pfetch(LINENUM line)
1392 {
1393         return p_line[line];
1394 }
1395
1396 /*
1397  * Return where in the patch file this hunk began, for error messages.
1398  */
1399 LINENUM
1400 pch_hunk_beg(void)
1401 {
1402         return p_hunk_beg;
1403 }
1404
1405 /*
1406  * Apply an ed script by feeding ed itself.
1407  */
1408 void
1409 do_ed_script(void)
1410 {
1411         char    *t;
1412         off_t   beginning_of_this_line;
1413         FILE    *pipefp = NULL;
1414         int     continuation;
1415
1416         if (!skip_rest_of_patch) {
1417                 if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1418                         unlink(TMPOUTNAME);
1419                         fatal("can't create temp file %s", TMPOUTNAME);
1420                 }
1421                 snprintf(buf, buf_size, "%s%s%s", _PATH_RED,
1422                     verbose ? " " : " -s ", TMPOUTNAME);
1423                 pipefp = popen(buf, "w");
1424         }
1425         for (;;) {
1426                 beginning_of_this_line = ftello(pfp);
1427                 if (pgets(true) == 0) {
1428                         next_intuit_at(beginning_of_this_line, p_input_line);
1429                         break;
1430                 }
1431                 p_input_line++;
1432                 for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1433                         ;
1434                 /* POSIX defines allowed commands as {a,c,d,i,s} */
1435                 if (isdigit((unsigned char)*buf) &&
1436                     (*t == 'a' || *t == 'c' || *t == 'd' || *t == 'i' || *t == 's')) {
1437                         if (pipefp != NULL)
1438                                 fputs(buf, pipefp);
1439                         if (*t == 's') {
1440                                 for (;;) {
1441                                         continuation = 0;
1442                                         t = strchr(buf, '\0') - 1;
1443                                         while (--t >= buf && *t == '\\')
1444                                                 continuation = !continuation;
1445                                         if (!continuation ||
1446                                             pgets(true) == 0)
1447                                                 break;
1448                                         if (pipefp != NULL)
1449                                                 fputs(buf, pipefp);
1450                                 }
1451                         } else if (*t != 'd') {
1452                                 while (pgets(true)) {
1453                                         p_input_line++;
1454                                         if (pipefp != NULL)
1455                                                 fputs(buf, pipefp);
1456                                         if (strEQ(buf, ".\n"))
1457                                                 break;
1458                                 }
1459                         }
1460                 } else {
1461                         next_intuit_at(beginning_of_this_line, p_input_line);
1462                         break;
1463                 }
1464         }
1465         if (pipefp == NULL)
1466                 return;
1467         fprintf(pipefp, "w\n");
1468         fprintf(pipefp, "q\n");
1469         fflush(pipefp);
1470         pclose(pipefp);
1471         ignore_signals();
1472         if (!check_only) {
1473                 if (move_file(TMPOUTNAME, outname) < 0) {
1474                         toutkeep = true;
1475                         chmod(TMPOUTNAME, filemode);
1476                 } else
1477                         chmod(outname, filemode);
1478         }
1479         set_signals(1);
1480 }
1481
1482 /*
1483  * Choose the name of the file to be patched based on POSIX rules.
1484  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1485  *       if the user specified --posix or set POSIXLY_CORRECT.
1486  */
1487 static char *
1488 posix_name(const struct file_name *names, bool assume_exists)
1489 {
1490         char *path = NULL;
1491         int i;
1492
1493         /*
1494          * POSIX states that the filename will be chosen from one
1495          * of the old, new and index names (in that order) if
1496          * the file exists relative to CWD after -p stripping.
1497          */
1498         for (i = 0; i < MAX_FILE; i++) {
1499                 if (names[i].path != NULL && names[i].exists) {
1500                         path = names[i].path;
1501                         break;
1502                 }
1503         }
1504         if (path == NULL && !assume_exists) {
1505                 /*
1506                  * No files found, look for something we can checkout from
1507                  * RCS/SCCS dirs.  Same order as above.
1508                  */
1509                 for (i = 0; i < MAX_FILE; i++) {
1510                         if (names[i].path != NULL &&
1511                             (path = checked_in(names[i].path)) != NULL)
1512                                 break;
1513                 }
1514                 /*
1515                  * Still no match?  Check to see if the diff could be creating
1516                  * a new file.
1517                  */
1518                 if (path == NULL && ok_to_create_file &&
1519                     names[NEW_FILE].path != NULL)
1520                         path = names[NEW_FILE].path;
1521         }
1522
1523         return path ? xstrdup(path) : NULL;
1524 }
1525
1526 static char *
1527 compare_names(const struct file_name *names, bool assume_exists, int phase)
1528 {
1529         size_t min_components, min_baselen, min_len, tmp;
1530         char *best = NULL;
1531         char *path;
1532         int i;
1533
1534         /*
1535          * The "best" name is the one with the fewest number of path
1536          * components, the shortest basename length, and the shortest
1537          * overall length (in that order).  We only use the Index: file
1538          * if neither of the old or new files could be intuited from
1539          * the diff header.
1540          */
1541         min_components = min_baselen = min_len = SIZE_MAX;
1542         for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1543                 path = names[i].path;
1544                 if (path == NULL ||
1545                     (phase == 1 && !names[i].exists && !assume_exists) ||
1546                     (phase == 2 && checked_in(path) == NULL))
1547                         continue;
1548                 if ((tmp = num_components(path)) > min_components)
1549                         continue;
1550                 if (tmp < min_components) {
1551                         min_components = tmp;
1552                         best = path;
1553                 }
1554                 if ((tmp = strlen(basename(path))) > min_baselen)
1555                         continue;
1556                 if (tmp < min_baselen) {
1557                         min_baselen = tmp;
1558                         best = path;
1559                 }
1560                 if ((tmp = strlen(path)) > min_len)
1561                         continue;
1562                 min_len = tmp;
1563                 best = path;
1564         }
1565         return best;
1566 }
1567
1568 /*
1569  * Choose the name of the file to be patched based the "best" one
1570  * available.
1571  */
1572 static char *
1573 best_name(const struct file_name *names, bool assume_exists)
1574 {
1575         char *best;
1576
1577         best = compare_names(names, assume_exists, 1);
1578         if (best == NULL) {
1579                 best = compare_names(names, assume_exists, 2);
1580                 /*
1581                  * Still no match?  Check to see if the diff could be creating
1582                  * a new file.
1583                  */
1584                 if (best == NULL && ok_to_create_file &&
1585                     names[NEW_FILE].path != NULL)
1586                         best = names[NEW_FILE].path;
1587         }
1588
1589         return best ? xstrdup(best) : NULL;
1590 }
1591
1592 static size_t
1593 num_components(const char *path)
1594 {
1595         size_t n;
1596         const char *cp;
1597
1598         for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1599                 while (*cp == '/')
1600                         cp++;           /* skip consecutive slashes */
1601         }
1602         return n;
1603 }
1604
1605 /*
1606  * Convert number at NPTR into LINENUM and save address of first
1607  * character that is not a digit in ENDPTR.  If conversion is not
1608  * possible, call fatal.
1609  */
1610 static LINENUM
1611 strtolinenum(char *nptr, char **endptr)
1612 {
1613         LINENUM rv;
1614         char c;
1615         char *p;
1616         const char *errstr;
1617
1618         for (p = nptr; isdigit((unsigned char)*p); p++)
1619                 ;
1620
1621         if (p == nptr)
1622                 malformed();
1623
1624         c = *p;
1625         *p = '\0';
1626
1627         rv = strtonum(nptr, 0, LINENUM_MAX, &errstr);
1628         if (errstr != NULL)
1629                 fatal("invalid line number at line %ld: `%s' is %s\n",
1630                     p_input_line, nptr, errstr);
1631
1632         *p = c;
1633         *endptr = p;
1634
1635         return rv;
1636 }