usr.bin/patch/pch.c

   1
   2 /*-
   3  * Copyright 1986, Larry Wall
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following condition is met:
   7  * 1. Redistributions of source code must retain the above copyright notice,
   8  * this condition and the following disclaimer.
   9  *
  10  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  11  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  12  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  13  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  14  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  15  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  16  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  17  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  18  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  19  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  20  * SUCH DAMAGE.
  21  *
  22  * patch - a program to apply diffs to original files
  23  *
  24  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  25  * behaviour
  26  *
  27  * $OpenBSD: pch.c,v 1.43 2014/11/18 17:03:35 tobias Exp $
  28  * $FreeBSD$
  29  */
  30
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33
  34 #include <ctype.h>
  35 #include <libgen.h>
  36 #include <limits.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                         ask("No file found--skip this patch? [n] ");
 220                         if (*buf != 'y')
 221                                 continue;
 222                         if (verbose)
 223                                 say("Skipping patch...\n");
 224                         free(filearg[0]);
 225                         filearg[0] = fetchname(bestguess, &exists, 0);
 226                         skip_rest_of_patch = true;
 227                         return true;
 228                 }
 229         }
 230         return true;
 231 }
 232
 233 static void
 234 p4_fetchname(struct file_name *name, char *str)
 235 {
 236         char *t, *h;
 237
 238         /* Skip leading whitespace. */
 239         while (isspace((unsigned char)*str))
 240                 str++;
 241
 242         /* Remove the file revision number. */
 243         for (t = str, h = NULL; *t != '\0' && !isspace((unsigned char)*t); t++)
 244                 if (*t == '#')
 245                         h = t;
 246         if (h != NULL)
 247                 *h = '\0';
 248
 249         name->path = fetchname(str, &name->exists, strippath);
 250 }
 251
 252 /* Determine what kind of diff is in the remaining part of the patch file. */
 253
 254 static int
 255 intuit_diff_type(void)
 256 {
 257         off_t   this_line = 0, previous_line;
 258         off_t   first_command_line = -1;
 259         LINENUM fcl_line = -1;
 260         bool    last_line_was_command = false, this_is_a_command = false;
 261         bool    stars_last_line = false, stars_this_line = false;
 262         char    *s, *t;
 263         int     indent, retval;
 264         struct file_name names[MAX_FILE];
 265
 266         memset(names, 0, sizeof(names));
 267         ok_to_create_file = false;
 268         fseeko(pfp, p_base, SEEK_SET);
 269         p_input_line = p_bline - 1;
 270         for (;;) {
 271                 previous_line = this_line;
 272                 last_line_was_command = this_is_a_command;
 273                 stars_last_line = stars_this_line;
 274                 this_line = ftello(pfp);
 275                 indent = 0;
 276                 p_input_line++;
 277                 if (pgets(false) == 0) {
 278                         if (first_command_line >= 0) {
 279                                 /* nothing but deletes!? */
 280                                 p_start = first_command_line;
 281                                 p_sline = fcl_line;
 282                                 retval = ED_DIFF;
 283                                 goto scan_exit;
 284                         } else {
 285                                 p_start = this_line;
 286                                 p_sline = p_input_line;
 287                                 retval = 0;
 288                                 goto scan_exit;
 289                         }
 290                 }
 291                 for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
 292                         if (*s == '\t')
 293                                 indent += 8 - (indent % 8);
 294                         else
 295                                 indent++;
 296                 }
 297                 for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
 298                         ;
 299                 this_is_a_command = (isdigit((unsigned char)*s) &&
 300                     (*t == 'd' || *t == 'c' || *t == 'a'));
 301                 if (first_command_line < 0 && this_is_a_command) {
 302                         first_command_line = this_line;
 303                         fcl_line = p_input_line;
 304                         p_indent = indent;      /* assume this for now */
 305                 }
 306                 if (!stars_last_line && strnEQ(s, "*** ", 4))
 307                         names[OLD_FILE].path = fetchname(s + 4,
 308                             &names[OLD_FILE].exists, strippath);
 309                 else if (strnEQ(s, "--- ", 4))
 310                         names[NEW_FILE].path = fetchname(s + 4,
 311                             &names[NEW_FILE].exists, strippath);
 312                 else if (strnEQ(s, "+++ ", 4))
 313                         /* pretend it is the old name */
 314                         names[OLD_FILE].path = fetchname(s + 4,
 315                             &names[OLD_FILE].exists, strippath);
 316                 else if (strnEQ(s, "Index:", 6))
 317                         names[INDEX_FILE].path = fetchname(s + 6,
 318                             &names[INDEX_FILE].exists, strippath);
 319                 else if (strnEQ(s, "Prereq:", 7)) {
 320                         for (t = s + 7; isspace((unsigned char)*t); t++)
 321                                 ;
 322                         revision = xstrdup(t);
 323                         for (t = revision;
 324                              *t && !isspace((unsigned char)*t); t++)
 325                                 ;
 326                         *t = '\0';
 327                         if (*revision == '\0') {
 328                                 free(revision);
 329                                 revision = NULL;
 330                         }
 331                 } else if (strnEQ(s, "==== ", 5)) {
 332                         /* Perforce-style diffs. */
 333                         if ((t = strstr(s + 5, " - ")) != NULL)
 334                                 p4_fetchname(&names[NEW_FILE], t + 3);
 335                         p4_fetchname(&names[OLD_FILE], s + 5);
 336                 }
 337                 if ((!diff_type || diff_type == ED_DIFF) &&
 338                     first_command_line >= 0 &&
 339                     strEQ(s, ".\n")) {
 340                         p_indent = indent;
 341                         p_start = first_command_line;
 342                         p_sline = fcl_line;
 343                         retval = ED_DIFF;
 344                         goto scan_exit;
 345                 }
 346                 if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
 347                         if (strnEQ(s + 4, "0,0", 3))
 348                                 ok_to_create_file = true;
 349                         p_indent = indent;
 350                         p_start = this_line;
 351                         p_sline = p_input_line;
 352                         retval = UNI_DIFF;
 353                         goto scan_exit;
 354                 }
 355                 stars_this_line = strnEQ(s, "********", 8);
 356                 if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
 357                     strnEQ(s, "*** ", 4)) {
 358                         if (strtolinenum(s + 4, &s) == 0)
 359                                 ok_to_create_file = true;
 360                         /*
 361                          * If this is a new context diff the character just
 362                          * at the end of the line is a '*'.
 363                          */
 364                         while (*s && *s != '\n')
 365                                 s++;
 366                         p_indent = indent;
 367                         p_start = previous_line;
 368                         p_sline = p_input_line - 1;
 369                         retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
 370                         goto scan_exit;
 371                 }
 372                 if ((!diff_type || diff_type == NORMAL_DIFF) &&
 373                     last_line_was_command &&
 374                     (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
 375                         p_start = previous_line;
 376                         p_sline = p_input_line - 1;
 377                         p_indent = indent;
 378                         retval = NORMAL_DIFF;
 379                         goto scan_exit;
 380                 }
 381         }
 382 scan_exit:
 383         if (retval == UNI_DIFF) {
 384                 /* unswap old and new */
 385                 struct file_name tmp = names[OLD_FILE];
 386                 names[OLD_FILE] = names[NEW_FILE];
 387                 names[NEW_FILE] = tmp;
 388         }
 389         if (filearg[0] == NULL) {
 390                 if (posix)
 391                         filearg[0] = posix_name(names, ok_to_create_file);
 392                 else {
 393                         /* Ignore the Index: name for context diffs, like GNU */
 394                         if (names[OLD_FILE].path != NULL ||
 395                             names[NEW_FILE].path != NULL) {
 396                                 free(names[INDEX_FILE].path);
 397                                 names[INDEX_FILE].path = NULL;
 398                         }
 399                         filearg[0] = best_name(names, ok_to_create_file);
 400                 }
 401         }
 402
 403         free(bestguess);
 404         bestguess = NULL;
 405         if (filearg[0] != NULL)
 406                 bestguess = xstrdup(filearg[0]);
 407         else if (!ok_to_create_file) {
 408                 /*
 409                  * We don't want to create a new file but we need a
 410                  * filename to set bestguess.  Avoid setting filearg[0]
 411                  * so the file is not created automatically.
 412                  */
 413                 if (posix)
 414                         bestguess = posix_name(names, true);
 415                 else
 416                         bestguess = best_name(names, true);
 417         }
 418         free(names[OLD_FILE].path);
 419         free(names[NEW_FILE].path);
 420         free(names[INDEX_FILE].path);
 421         return retval;
 422 }
 423
 424 /*
 425  * Remember where this patch ends so we know where to start up again.
 426  */
 427 static void
 428 next_intuit_at(off_t file_pos, LINENUM file_line)
 429 {
 430         p_base = file_pos;
 431         p_bline = file_line;
 432 }
 433
 434 /*
 435  * Basically a verbose fseeko() to the actual diff listing.
 436  */
 437 static void
 438 skip_to(off_t file_pos, LINENUM file_line)
 439 {
 440         size_t  len;
 441
 442         if (p_base > file_pos)
 443                 fatal("Internal error: seek %lld>%lld\n",
 444                    (long long)p_base, (long long)file_pos);
 445         if (verbose && p_base < file_pos) {
 446                 fseeko(pfp, p_base, SEEK_SET);
 447                 say("The text leading up to this was:\n--------------------------\n");
 448                 while (ftello(pfp) < file_pos) {
 449                         len = pgets(false);
 450                         if (len == 0)
 451                                 fatal("Unexpected end of file\n");
 452                         say("|%s", buf);
 453                 }
 454                 say("--------------------------\n");
 455         } else
 456                 fseeko(pfp, file_pos, SEEK_SET);
 457         p_input_line = file_line - 1;
 458 }
 459
 460 /* Make this a function for better debugging.  */
 461 static void
 462 malformed(void)
 463 {
 464         fatal("malformed patch at line %ld: %s", p_input_line, buf);
 465         /* about as informative as "Syntax error" in C */
 466 }
 467
 468 /*
 469  * True if the line has been discarded (i.e. it is a line saying
 470  *  "\ No newline at end of file".)
 471  */
 472 static bool
 473 remove_special_line(void)
 474 {
 475         int     c;
 476
 477         c = fgetc(pfp);
 478         if (c == '\\') {
 479                 do {
 480                         c = fgetc(pfp);
 481                 } while (c != EOF && c != '\n');
 482
 483                 return true;
 484         }
 485         if (c != EOF)
 486                 fseeko(pfp, -1, SEEK_CUR);
 487
 488         return false;
 489 }
 490
 491 /*
 492  * True if there is more of the current diff listing to process.
 493  */
 494 bool
 495 another_hunk(void)
 496 {
 497         off_t   line_beginning;                 /* file pos of the current line */
 498         LINENUM repl_beginning;                 /* index of --- line */
 499         LINENUM fillcnt;                        /* #lines of missing ptrn or repl */
 500         LINENUM fillsrc;                        /* index of first line to copy */
 501         LINENUM filldst;                        /* index of first missing line */
 502         bool    ptrn_spaces_eaten;              /* ptrn was slightly misformed */
 503         bool    repl_could_be_missing;          /* no + or ! lines in this hunk */
 504         bool    repl_missing;                   /* we are now backtracking */
 505         off_t   repl_backtrack_position;        /* file pos of first repl line */
 506         LINENUM repl_patch_line;                /* input line number for same */
 507         LINENUM ptrn_copiable;                  /* # of copiable lines in ptrn */
 508         char    *s;
 509         size_t  len;
 510         int     context = 0;
 511
 512         while (p_end >= 0) {
 513                 if (p_end == p_efake)
 514                         p_end = p_bfake;        /* don't free twice */
 515                 else
 516                         free(p_line[p_end]);
 517                 p_end--;
 518         }
 519         p_efake = -1;
 520
 521         p_max = hunkmax;        /* gets reduced when --- found */
 522         if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
 523                 line_beginning = ftello(pfp);
 524                 repl_beginning = 0;
 525                 fillcnt = 0;
 526                 fillsrc = 0;
 527                 filldst = 0;
 528                 ptrn_spaces_eaten = false;
 529                 repl_could_be_missing = true;
 530                 repl_missing = false;
 531                 repl_backtrack_position = 0;
 532                 repl_patch_line = 0;
 533                 ptrn_copiable = 0;
 534
 535                 len = pgets(true);
 536                 p_input_line++;
 537                 if (len == 0 || strnNE(buf, "********", 8)) {
 538                         next_intuit_at(line_beginning, p_input_line);
 539                         return false;
 540                 }
 541                 p_context = 100;
 542                 p_hunk_beg = p_input_line + 1;
 543                 while (p_end < p_max) {
 544                         line_beginning = ftello(pfp);
 545                         len = pgets(true);
 546                         p_input_line++;
 547                         if (len == 0) {
 548                                 if (p_max - p_end < 4) {
 549                                         /* assume blank lines got chopped */
 550                                         strlcpy(buf, "  \n", buf_size);
 551                                 } else {
 552                                         if (repl_beginning && repl_could_be_missing) {
 553                                                 repl_missing = true;
 554                                                 goto hunk_done;
 555                                         }
 556                                         fatal("unexpected end of file in patch\n");
 557                                 }
 558                         }
 559                         p_end++;
 560                         if (p_end >= hunkmax)
 561                                 fatal("Internal error: hunk larger than hunk "
 562                                     "buffer size");
 563                         p_char[p_end] = *buf;
 564                         p_line[p_end] = NULL;
 565                         switch (*buf) {
 566                         case '*':
 567                                 if (strnEQ(buf, "********", 8)) {
 568                                         if (repl_beginning && repl_could_be_missing) {
 569                                                 repl_missing = true;
 570                                                 goto hunk_done;
 571                                         } else
 572                                                 fatal("unexpected end of hunk "
 573                                                     "at line %ld\n",
 574                                                     p_input_line);
 575                                 }
 576                                 if (p_end != 0) {
 577                                         if (repl_beginning && repl_could_be_missing) {
 578                                                 repl_missing = true;
 579                                                 goto hunk_done;
 580                                         }
 581                                         fatal("unexpected *** at line %ld: %s",
 582                                             p_input_line, buf);
 583                                 }
 584                                 context = 0;
 585                                 p_line[p_end] = savestr(buf);
 586                                 if (out_of_mem) {
 587                                         p_end--;
 588                                         return false;
 589                                 }
 590                                 for (s = buf;
 591                                      *s && !isdigit((unsigned char)*s); s++)
 592                                         ;
 593                                 if (!*s)
 594                                         malformed();
 595                                 if (strnEQ(s, "0,0", 3))
 596                                         memmove(s, s + 2, strlen(s + 2) + 1);
 597                                 p_first = strtolinenum(s, &s);
 598                                 if (*s == ',') {
 599                                         for (;
 600                                              *s && !isdigit((unsigned char)*s); s++)
 601                                                 ;
 602                                         if (!*s)
 603                                                 malformed();
 604                                         p_ptrn_lines = strtolinenum(s, &s) - p_first + 1;
 605                                         if (p_ptrn_lines < 0)
 606                                                 malformed();
 607                                 } else if (p_first)
 608                                         p_ptrn_lines = 1;
 609                                 else {
 610                                         p_ptrn_lines = 0;
 611                                         p_first = 1;
 612                                 }
 613                                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 614                                     p_ptrn_lines >= LINENUM_MAX - 6)
 615                                         malformed();
 616
 617                                 /* we need this much at least */
 618                                 p_max = p_ptrn_lines + 6;
 619                                 while (p_max >= hunkmax)
 620                                         grow_hunkmax();
 621                                 p_max = hunkmax;
 622                                 break;
 623                         case '-':
 624                                 if (buf[1] == '-') {
 625                                         if (repl_beginning ||
 626                                             (p_end != p_ptrn_lines + 1 +
 627                                             (p_char[p_end - 1] == '\n'))) {
 628                                                 if (p_end == 1) {
 629                                                         /*
 630                                                          * `old' lines were omitted;
 631                                                          * set up to fill them in
 632                                                          * from 'new' context lines.
 633                                                          */
 634                                                         p_end = p_ptrn_lines + 1;
 635                                                         fillsrc = p_end + 1;
 636                                                         filldst = 1;
 637                                                         fillcnt = p_ptrn_lines;
 638                                                 } else {
 639                                                         if (repl_beginning) {
 640                                                                 if (repl_could_be_missing) {
 641                                                                         repl_missing = true;
 642                                                                         goto hunk_done;
 643                                                                 }
 644                                                                 fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
 645                                                                     p_input_line, p_hunk_beg + repl_beginning);
 646                                                         } else {
 647                                                                 fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
 648                                                                     (p_end <= p_ptrn_lines
 649                                                                     ? "Premature"
 650                                                                     : "Overdue"),
 651                                                                     p_input_line, p_hunk_beg);
 652                                                         }
 653                                                 }
 654                                         }
 655                                         repl_beginning = p_end;
 656                                         repl_backtrack_position = ftello(pfp);
 657                                         repl_patch_line = p_input_line;
 658                                         p_line[p_end] = savestr(buf);
 659                                         if (out_of_mem) {
 660                                                 p_end--;
 661                                                 return false;
 662                                         }
 663                                         p_char[p_end] = '=';
 664                                         for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 665                                                 ;
 666                                         if (!*s)
 667                                                 malformed();
 668                                         p_newfirst = strtolinenum(s, &s);
 669                                         if (*s == ',') {
 670                                                 for (; *s && !isdigit((unsigned char)*s); s++)
 671                                                         ;
 672                                                 if (!*s)
 673                                                         malformed();
 674                                                 p_repl_lines = strtolinenum(s, &s) -
 675                                                     p_newfirst + 1;
 676                                                 if (p_repl_lines < 0)
 677                                                         malformed();
 678                                         } else if (p_newfirst)
 679                                                 p_repl_lines = 1;
 680                                         else {
 681                                                 p_repl_lines = 0;
 682                                                 p_newfirst = 1;
 683                                         }
 684                                         if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
 685                                             p_repl_lines >= LINENUM_MAX - p_end)
 686                                                 malformed();
 687                                         p_max = p_repl_lines + p_end;
 688                                         if (p_max > MAXHUNKSIZE)
 689                                                 fatal("hunk too large (%ld lines) at line %ld: %s",
 690                                                     p_max, p_input_line, buf);
 691                                         while (p_max >= hunkmax)
 692                                                 grow_hunkmax();
 693                                         if (p_repl_lines != ptrn_copiable &&
 694                                             (p_context != 0 || p_repl_lines != 1))
 695                                                 repl_could_be_missing = false;
 696                                         break;
 697                                 }
 698                                 goto change_line;
 699                         case '+':
 700                         case '!':
 701                                 repl_could_be_missing = false;
 702                 change_line:
 703                                 if (buf[1] == '\n' && canonicalize)
 704                                         strlcpy(buf + 1, " \n", buf_size - 1);
 705                                 if (!isspace((unsigned char)buf[1]) &&
 706                                     buf[1] != '>' && buf[1] != '<' &&
 707                                     repl_beginning && repl_could_be_missing) {
 708                                         repl_missing = true;
 709                                         goto hunk_done;
 710                                 }
 711                                 if (context >= 0) {
 712                                         if (context < p_context)
 713                                                 p_context = context;
 714                                         context = -1000;
 715                                 }
 716                                 p_line[p_end] = savestr(buf + 2);
 717                                 if (out_of_mem) {
 718                                         p_end--;
 719                                         return false;
 720                                 }
 721                                 if (p_end == p_ptrn_lines) {
 722                                         if (remove_special_line()) {
 723                                                 int     l;
 724
 725                                                 l = strlen(p_line[p_end]) - 1;
 726                                                 (p_line[p_end])[l] = 0;
 727                                         }
 728                                 }
 729                                 break;
 730                         case '\t':
 731                         case '\n':      /* assume the 2 spaces got eaten */
 732                                 if (repl_beginning && repl_could_be_missing &&
 733                                     (!ptrn_spaces_eaten ||
 734                                     diff_type == NEW_CONTEXT_DIFF)) {
 735                                         repl_missing = true;
 736                                         goto hunk_done;
 737                                 }
 738                                 p_line[p_end] = savestr(buf);
 739                                 if (out_of_mem) {
 740                                         p_end--;
 741                                         return false;
 742                                 }
 743                                 if (p_end != p_ptrn_lines + 1) {
 744                                         ptrn_spaces_eaten |= (repl_beginning != 0);
 745                                         context++;
 746                                         if (!repl_beginning)
 747                                                 ptrn_copiable++;
 748                                         p_char[p_end] = ' ';
 749                                 }
 750                                 break;
 751                         case ' ':
 752                                 if (!isspace((unsigned char)buf[1]) &&
 753                                     repl_beginning && repl_could_be_missing) {
 754                                         repl_missing = true;
 755                                         goto hunk_done;
 756                                 }
 757                                 context++;
 758                                 if (!repl_beginning)
 759                                         ptrn_copiable++;
 760                                 p_line[p_end] = savestr(buf + 2);
 761                                 if (out_of_mem) {
 762                                         p_end--;
 763                                         return false;
 764                                 }
 765                                 break;
 766                         default:
 767                                 if (repl_beginning && repl_could_be_missing) {
 768                                         repl_missing = true;
 769                                         goto hunk_done;
 770                                 }
 771                                 malformed();
 772                         }
 773                         /* set up p_len for strncmp() so we don't have to */
 774                         /* assume null termination */
 775                         if (p_line[p_end])
 776                                 p_len[p_end] = strlen(p_line[p_end]);
 777                         else
 778                                 p_len[p_end] = 0;
 779                 }
 780
 781 hunk_done:
 782                 if (p_end >= 0 && !repl_beginning)
 783                         fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
 784
 785                 if (repl_missing) {
 786
 787                         /* reset state back to just after --- */
 788                         p_input_line = repl_patch_line;
 789                         for (p_end--; p_end > repl_beginning; p_end--)
 790                                 free(p_line[p_end]);
 791                         fseeko(pfp, repl_backtrack_position, SEEK_SET);
 792
 793                         /* redundant 'new' context lines were omitted - set */
 794                         /* up to fill them in from the old file context */
 795                         if (!p_context && p_repl_lines == 1) {
 796                                 p_repl_lines = 0;
 797                                 p_max--;
 798                         }
 799                         fillsrc = 1;
 800                         filldst = repl_beginning + 1;
 801                         fillcnt = p_repl_lines;
 802                         p_end = p_max;
 803                 } else if (!p_context && fillcnt == 1) {
 804                         /* the first hunk was a null hunk with no context */
 805                         /* and we were expecting one line -- fix it up. */
 806                         while (filldst < p_end) {
 807                                 p_line[filldst] = p_line[filldst + 1];
 808                                 p_char[filldst] = p_char[filldst + 1];
 809                                 p_len[filldst] = p_len[filldst + 1];
 810                                 filldst++;
 811                         }
 812 #if 0
 813                         repl_beginning--;       /* this doesn't need to be fixed */
 814 #endif
 815                         p_end--;
 816                         p_first++;      /* do append rather than insert */
 817                         fillcnt = 0;
 818                         p_ptrn_lines = 0;
 819                 }
 820                 if (diff_type == CONTEXT_DIFF &&
 821                     (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
 822                         if (verbose)
 823                                 say("%s\n%s\n%s\n",
 824                                     "(Fascinating--this is really a new-style context diff but without",
 825                                     "the telltale extra asterisks on the *** line that usually indicate",
 826                                     "the new style...)");
 827                         diff_type = NEW_CONTEXT_DIFF;
 828                 }
 829                 /* if there were omitted context lines, fill them in now */
 830                 if (fillcnt) {
 831                         p_bfake = filldst;      /* remember where not to free() */
 832                         p_efake = filldst + fillcnt - 1;
 833                         while (fillcnt-- > 0) {
 834                                 while (fillsrc <= p_end && p_char[fillsrc] != ' ')
 835                                         fillsrc++;
 836                                 if (fillsrc > p_end)
 837                                         fatal("replacement text or line numbers mangled in hunk at line %ld\n",
 838                                             p_hunk_beg);
 839                                 p_line[filldst] = p_line[fillsrc];
 840                                 p_char[filldst] = p_char[fillsrc];
 841                                 p_len[filldst] = p_len[fillsrc];
 842                                 fillsrc++;
 843                                 filldst++;
 844                         }
 845                         while (fillsrc <= p_end && fillsrc != repl_beginning &&
 846                             p_char[fillsrc] != ' ')
 847                                 fillsrc++;
 848 #ifdef DEBUGGING
 849                         if (debug & 64)
 850                                 printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
 851                                 fillsrc, filldst, repl_beginning, p_end + 1);
 852 #endif
 853                         if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
 854                                 malformed();
 855                         if (filldst != p_end + 1 && filldst != repl_beginning)
 856                                 malformed();
 857                 }
 858                 if (p_line[p_end] != NULL) {
 859                         if (remove_special_line()) {
 860                                 p_len[p_end] -= 1;
 861                                 (p_line[p_end])[p_len[p_end]] = 0;
 862                         }
 863                 }
 864         } else if (diff_type == UNI_DIFF) {
 865                 LINENUM fillold;        /* index of old lines */
 866                 LINENUM fillnew;        /* index of new lines */
 867                 char    ch;
 868
 869                 line_beginning = ftello(pfp); /* file pos of the current line */
 870                 len = pgets(true);
 871                 p_input_line++;
 872                 if (len == 0 || strnNE(buf, "@@ -", 4)) {
 873                         next_intuit_at(line_beginning, p_input_line);
 874                         return false;
 875                 }
 876                 s = buf + 4;
 877                 if (!*s)
 878                         malformed();
 879                 p_first = strtolinenum(s, &s);
 880                 if (*s == ',') {
 881                         p_ptrn_lines = strtolinenum(s + 1, &s);
 882                 } else
 883                         p_ptrn_lines = 1;
 884                 if (*s == ' ')
 885                         s++;
 886                 if (*s != '+' || !*++s)
 887                         malformed();
 888                 p_newfirst = strtolinenum(s, &s);
 889                 if (*s == ',') {
 890                         p_repl_lines = strtolinenum(s + 1, &s);
 891                 } else
 892                         p_repl_lines = 1;
 893                 if (*s == ' ')
 894                         s++;
 895                 if (*s != '@')
 896                         malformed();
 897                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 898                     p_newfirst > LINENUM_MAX - p_repl_lines ||
 899                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
 900                         malformed();
 901                 if (!p_ptrn_lines)
 902                         p_first++;      /* do append rather than insert */
 903                 p_max = p_ptrn_lines + p_repl_lines + 1;
 904                 while (p_max >= hunkmax)
 905                         grow_hunkmax();
 906                 fillold = 1;
 907                 fillnew = fillold + p_ptrn_lines;
 908                 p_end = fillnew + p_repl_lines;
 909                 snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
 910                     p_first + p_ptrn_lines - 1);
 911                 p_line[0] = savestr(buf);
 912                 if (out_of_mem) {
 913                         p_end = -1;
 914                         return false;
 915                 }
 916                 p_char[0] = '*';
 917                 snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
 918                     p_newfirst + p_repl_lines - 1);
 919                 p_line[fillnew] = savestr(buf);
 920                 if (out_of_mem) {
 921                         p_end = 0;
 922                         return false;
 923                 }
 924                 p_char[fillnew++] = '=';
 925                 p_context = 100;
 926                 context = 0;
 927                 p_hunk_beg = p_input_line + 1;
 928                 while (fillold <= p_ptrn_lines || fillnew <= p_end) {
 929                         line_beginning = ftello(pfp);
 930                         len = pgets(true);
 931                         p_input_line++;
 932                         if (len == 0) {
 933                                 if (p_max - fillnew < 3) {
 934                                         /* assume blank lines got chopped */
 935                                         strlcpy(buf, " \n", buf_size);
 936                                 } else {
 937                                         fatal("unexpected end of file in patch\n");
 938                                 }
 939                         }
 940                         if (*buf == '\t' || *buf == '\n') {
 941                                 ch = ' ';       /* assume the space got eaten */
 942                                 s = savestr(buf);
 943                         } else {
 944                                 ch = *buf;
 945                                 s = savestr(buf + 1);
 946                         }
 947                         if (out_of_mem) {
 948                                 while (--fillnew > p_ptrn_lines)
 949                                         free(p_line[fillnew]);
 950                                 p_end = fillold - 1;
 951                                 return false;
 952                         }
 953                         switch (ch) {
 954                         case '-':
 955                                 if (fillold > p_ptrn_lines) {
 956                                         free(s);
 957                                         p_end = fillnew - 1;
 958                                         malformed();
 959                                 }
 960                                 p_char[fillold] = ch;
 961                                 p_line[fillold] = s;
 962                                 p_len[fillold++] = strlen(s);
 963                                 if (fillold > p_ptrn_lines) {
 964                                         if (remove_special_line()) {
 965                                                 p_len[fillold - 1] -= 1;
 966                                                 s[p_len[fillold - 1]] = 0;
 967                                         }
 968                                 }
 969                                 break;
 970                         case '=':
 971                                 ch = ' ';
 972                                 /* FALL THROUGH */
 973                         case ' ':
 974                                 if (fillold > p_ptrn_lines) {
 975                                         free(s);
 976                                         while (--fillnew > p_ptrn_lines)
 977                                                 free(p_line[fillnew]);
 978                                         p_end = fillold - 1;
 979                                         malformed();
 980                                 }
 981                                 context++;
 982                                 p_char[fillold] = ch;
 983                                 p_line[fillold] = s;
 984                                 p_len[fillold++] = strlen(s);
 985                                 s = savestr(s);
 986                                 if (out_of_mem) {
 987                                         while (--fillnew > p_ptrn_lines)
 988                                                 free(p_line[fillnew]);
 989                                         p_end = fillold - 1;
 990                                         return false;
 991                                 }
 992                                 if (fillold > p_ptrn_lines) {
 993                                         if (remove_special_line()) {
 994                                                 p_len[fillold - 1] -= 1;
 995                                                 s[p_len[fillold - 1]] = 0;
 996                                         }
 997                                 }
 998                                 /* FALL THROUGH */
 999                         case '+':
1000                                 if (fillnew > p_end) {
1001                                         free(s);
1002                                         while (--fillnew > p_ptrn_lines)
1003                                                 free(p_line[fillnew]);
1004                                         p_end = fillold - 1;
1005                                         malformed();
1006                                 }
1007                                 p_char[fillnew] = ch;
1008                                 p_line[fillnew] = s;
1009                                 p_len[fillnew++] = strlen(s);
1010                                 if (fillold > p_ptrn_lines) {
1011                                         if (remove_special_line()) {
1012                                                 p_len[fillnew - 1] -= 1;
1013                                                 s[p_len[fillnew - 1]] = 0;
1014                                         }
1015                                 }
1016                                 break;
1017                         default:
1018                                 p_end = fillnew;
1019                                 malformed();
1020                         }
1021                         if (ch != ' ' && context > 0) {
1022                                 if (context < p_context)
1023                                         p_context = context;
1024                                 context = -1000;
1025                         }
1026                 }               /* while */
1027         } else {                /* normal diff--fake it up */
1028                 char    hunk_type;
1029                 int     i;
1030                 LINENUM min, max;
1031
1032                 line_beginning = ftello(pfp);
1033                 p_context = 0;
1034                 len = pgets(true);
1035                 p_input_line++;
1036                 if (len == 0 || !isdigit((unsigned char)*buf)) {
1037                         next_intuit_at(line_beginning, p_input_line);
1038                         return false;
1039                 }
1040                 p_first = strtolinenum(buf, &s);
1041                 if (*s == ',') {
1042                         p_ptrn_lines = strtolinenum(s + 1, &s) - p_first + 1;
1043                         if (p_ptrn_lines < 0)
1044                                 malformed();
1045                 } else
1046                         p_ptrn_lines = (*s != 'a');
1047                 hunk_type = *s;
1048                 if (hunk_type == 'a')
1049                         p_first++;      /* do append rather than insert */
1050                 min = strtolinenum(s + 1, &s);
1051                 if (*s == ',')
1052                         max = strtolinenum(s + 1, &s);
1053                 else
1054                         max = min;
1055                 if (min < 0 || min > max || max - min == LINENUM_MAX)
1056                         malformed();
1057                 if (hunk_type == 'd')
1058                         min++;
1059                 p_newfirst = min;
1060                 p_repl_lines = max - min + 1;
1061                 if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1062                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1063                         malformed();
1064                 p_end = p_ptrn_lines + p_repl_lines + 1;
1065                 if (p_end > MAXHUNKSIZE)
1066                         fatal("hunk too large (%ld lines) at line %ld: %s",
1067                             p_end, p_input_line, buf);
1068                 while (p_end >= hunkmax)
1069                         grow_hunkmax();
1070                 snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1071                     p_first + p_ptrn_lines - 1);
1072                 p_line[0] = savestr(buf);
1073                 if (out_of_mem) {
1074                         p_end = -1;
1075                         return false;
1076                 }
1077                 p_char[0] = '*';
1078                 for (i = 1; i <= p_ptrn_lines; i++) {
1079                         len = pgets(true);
1080                         p_input_line++;
1081                         if (len == 0)
1082                                 fatal("unexpected end of file in patch at line %ld\n",
1083                                     p_input_line);
1084                         if (*buf != '<')
1085                                 fatal("< expected at line %ld of patch\n",
1086                                     p_input_line);
1087                         p_line[i] = savestr(buf + 2);
1088                         if (out_of_mem) {
1089                                 p_end = i - 1;
1090                                 return false;
1091                         }
1092                         p_len[i] = strlen(p_line[i]);
1093                         p_char[i] = '-';
1094                 }
1095
1096                 if (remove_special_line()) {
1097                         p_len[i - 1] -= 1;
1098                         (p_line[i - 1])[p_len[i - 1]] = 0;
1099                 }
1100                 if (hunk_type == 'c') {
1101                         len = pgets(true);
1102                         p_input_line++;
1103                         if (len == 0)
1104                                 fatal("unexpected end of file in patch at line %ld\n",
1105                                     p_input_line);
1106                         if (*buf != '-')
1107                                 fatal("--- expected at line %ld of patch\n",
1108                                     p_input_line);
1109                 }
1110                 snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1111                 p_line[i] = savestr(buf);
1112                 if (out_of_mem) {
1113                         p_end = i - 1;
1114                         return false;
1115                 }
1116                 p_char[i] = '=';
1117                 for (i++; i <= p_end; i++) {
1118                         len = pgets(true);
1119                         p_input_line++;
1120                         if (len == 0)
1121                                 fatal("unexpected end of file in patch at line %ld\n",
1122                                     p_input_line);
1123                         if (*buf != '>')
1124                                 fatal("> expected at line %ld of patch\n",
1125                                     p_input_line);
1126                         p_line[i] = savestr(buf + 2);
1127                         if (out_of_mem) {
1128                                 p_end = i - 1;
1129                                 return false;
1130                         }
1131                         p_len[i] = strlen(p_line[i]);
1132                         p_char[i] = '+';
1133                 }
1134
1135                 if (remove_special_line()) {
1136                         p_len[i - 1] -= 1;
1137                         (p_line[i - 1])[p_len[i - 1]] = 0;
1138                 }
1139         }
1140         if (reverse)            /* backwards patch? */
1141                 if (!pch_swap())
1142                         say("Not enough memory to swap next hunk!\n");
1143 #ifdef DEBUGGING
1144         if (debug & 2) {
1145                 int     i;
1146                 char    special;
1147
1148                 for (i = 0; i <= p_end; i++) {
1149                         if (i == p_ptrn_lines)
1150                                 special = '^';
1151                         else
1152                                 special = ' ';
1153                         fprintf(stderr, "%3d %c %c %s", i, p_char[i],
1154                             special, p_line[i]);
1155                         fflush(stderr);
1156                 }
1157         }
1158 #endif
1159         if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1160                 p_char[p_end + 1] = '^';        /* add a stopper for apply_hunk */
1161         return true;
1162 }
1163
1164 /*
1165  * Input a line from the patch file.
1166  * Worry about indentation if do_indent is true.
1167  * The line is read directly into the buf global variable which
1168  * is resized if necessary in order to hold the complete line.
1169  * Returns the number of characters read including the terminating
1170  * '\n', if any.
1171  */
1172 size_t
1173 pgets(bool do_indent)
1174 {
1175         char *line;
1176         size_t len;
1177         int indent = 0, skipped = 0;
1178
1179         line = fgetln(pfp, &len);
1180         if (line != NULL) {
1181                 if (len + 1 > buf_size) {
1182                         while (len + 1 > buf_size)
1183                                 buf_size *= 2;
1184                         free(buf);
1185                         buf = malloc(buf_size);
1186                         if (buf == NULL)
1187                                 fatal("out of memory\n");
1188                 }
1189                 if (do_indent == 1 && p_indent) {
1190                         for (;
1191                             indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1192                             line++, skipped++) {
1193                                 if (*line == '\t')
1194                                         indent += 8 - (indent %7);
1195                                 else
1196                                         indent++;
1197                         }
1198                 }
1199                 memcpy(buf, line, len - skipped);
1200                 buf[len - skipped] = '\0';
1201         }
1202         return len;
1203 }
1204
1205
1206 /*
1207  * Reverse the old and new portions of the current hunk.
1208  */
1209 bool
1210 pch_swap(void)
1211 {
1212         char    **tp_line;      /* the text of the hunk */
1213         unsigned short  *tp_len;/* length of each line */
1214         char    *tp_char;       /* +, -, and ! */
1215         LINENUM i;
1216         LINENUM n;
1217         bool    blankline = false;
1218         char    *s;
1219
1220         i = p_first;
1221         p_first = p_newfirst;
1222         p_newfirst = i;
1223
1224         /* make a scratch copy */
1225
1226         tp_line = p_line;
1227         tp_len = p_len;
1228         tp_char = p_char;
1229         p_line = NULL;  /* force set_hunkmax to allocate again */
1230         p_len = NULL;
1231         p_char = NULL;
1232         set_hunkmax();
1233         if (p_line == NULL || p_len == NULL || p_char == NULL) {
1234
1235                 free(p_line);
1236                 p_line = tp_line;
1237                 free(p_len);
1238                 p_len = tp_len;
1239                 free(p_char);
1240                 p_char = tp_char;
1241                 return false;   /* not enough memory to swap hunk! */
1242         }
1243         /* now turn the new into the old */
1244
1245         i = p_ptrn_lines + 1;
1246         if (tp_char[i] == '\n') {       /* account for possible blank line */
1247                 blankline = true;
1248                 i++;
1249         }
1250         if (p_efake >= 0) {     /* fix non-freeable ptr range */
1251                 if (p_efake <= i)
1252                         n = p_end - i + 1;
1253                 else
1254                         n = -i;
1255                 p_efake += n;
1256                 p_bfake += n;
1257         }
1258         for (n = 0; i <= p_end; i++, n++) {
1259                 p_line[n] = tp_line[i];
1260                 p_char[n] = tp_char[i];
1261                 if (p_char[n] == '+')
1262                         p_char[n] = '-';
1263                 p_len[n] = tp_len[i];
1264         }
1265         if (blankline) {
1266                 i = p_ptrn_lines + 1;
1267                 p_line[n] = tp_line[i];
1268                 p_char[n] = tp_char[i];
1269                 p_len[n] = tp_len[i];
1270                 n++;
1271         }
1272         if (p_char[0] != '=')
1273                 fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1274                     p_input_line, p_char[0]);
1275         p_char[0] = '*';
1276         for (s = p_line[0]; *s; s++)
1277                 if (*s == '-')
1278                         *s = '*';
1279
1280         /* now turn the old into the new */
1281
1282         if (p_char[0] != '*')
1283                 fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1284                     p_input_line, p_char[0]);
1285         tp_char[0] = '=';
1286         for (s = tp_line[0]; *s; s++)
1287                 if (*s == '*')
1288                         *s = '-';
1289         for (i = 0; n <= p_end; i++, n++) {
1290                 p_line[n] = tp_line[i];
1291                 p_char[n] = tp_char[i];
1292                 if (p_char[n] == '-')
1293                         p_char[n] = '+';
1294                 p_len[n] = tp_len[i];
1295         }
1296
1297         if (i != p_ptrn_lines + 1)
1298                 fatal("Malformed patch at line %ld: expected %ld lines, "
1299                     "got %ld\n",
1300                     p_input_line, p_ptrn_lines + 1, i);
1301
1302         i = p_ptrn_lines;
1303         p_ptrn_lines = p_repl_lines;
1304         p_repl_lines = i;
1305
1306         free(tp_line);
1307         free(tp_len);
1308         free(tp_char);
1309
1310         return true;
1311 }
1312
1313 /*
1314  * Return the specified line position in the old file of the old context.
1315  */
1316 LINENUM
1317 pch_first(void)
1318 {
1319         return p_first;
1320 }
1321
1322 /*
1323  * Return the number of lines of old context.
1324  */
1325 LINENUM
1326 pch_ptrn_lines(void)
1327 {
1328         return p_ptrn_lines;
1329 }
1330
1331 /*
1332  * Return the probable line position in the new file of the first line.
1333  */
1334 LINENUM
1335 pch_newfirst(void)
1336 {
1337         return p_newfirst;
1338 }
1339
1340 /*
1341  * Return the number of lines in the replacement text including context.
1342  */
1343 LINENUM
1344 pch_repl_lines(void)
1345 {
1346         return p_repl_lines;
1347 }
1348
1349 /*
1350  * Return the number of lines in the whole hunk.
1351  */
1352 LINENUM
1353 pch_end(void)
1354 {
1355         return p_end;
1356 }
1357
1358 /*
1359  * Return the number of context lines before the first changed line.
1360  */
1361 LINENUM
1362 pch_context(void)
1363 {
1364         return p_context;
1365 }
1366
1367 /*
1368  * Return the length of a particular patch line.
1369  */
1370 unsigned short
1371 pch_line_len(LINENUM line)
1372 {
1373         return p_len[line];
1374 }
1375
1376 /*
1377  * Return the control character (+, -, *, !, etc) for a patch line.
1378  */
1379 char
1380 pch_char(LINENUM line)
1381 {
1382         return p_char[line];
1383 }
1384
1385 /*
1386  * Return a pointer to a particular patch line.
1387  */
1388 char *
1389 pfetch(LINENUM line)
1390 {
1391         return p_line[line];
1392 }
1393
1394 /*
1395  * Return where in the patch file this hunk began, for error messages.
1396  */
1397 LINENUM
1398 pch_hunk_beg(void)
1399 {
1400         return p_hunk_beg;
1401 }
1402
1403 /*
1404  * Apply an ed script by feeding ed itself.
1405  */
1406 void
1407 do_ed_script(void)
1408 {
1409         char    *t;
1410         off_t   beginning_of_this_line;
1411         FILE    *pipefp = NULL;
1412
1413         if (!skip_rest_of_patch) {
1414                 if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1415                         unlink(TMPOUTNAME);
1416                         fatal("can't create temp file %s", TMPOUTNAME);
1417                 }
1418                 snprintf(buf, buf_size, "%s%s%s", _PATH_ED,
1419                     verbose ? " " : " -s ", TMPOUTNAME);
1420                 pipefp = popen(buf, "w");
1421         }
1422         for (;;) {
1423                 beginning_of_this_line = ftello(pfp);
1424                 if (pgets(true) == 0) {
1425                         next_intuit_at(beginning_of_this_line, p_input_line);
1426                         break;
1427                 }
1428                 p_input_line++;
1429                 for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1430                         ;
1431                 /* POSIX defines allowed commands as {a,c,d,i,s} */
1432                 if (isdigit((unsigned char)*buf) &&
1433                     (*t == 'a' || *t == 'c' || *t == 'd' || *t == 'i' || *t == 's')) {
1434                         if (pipefp != NULL)
1435                                 fputs(buf, pipefp);
1436                         if (*t != 'd') {
1437                                 while (pgets(true)) {
1438                                         p_input_line++;
1439                                         if (pipefp != NULL)
1440                                                 fputs(buf, pipefp);
1441                                         if (strEQ(buf, ".\n"))
1442                                                 break;
1443                                 }
1444                         }
1445                 } else {
1446                         next_intuit_at(beginning_of_this_line, p_input_line);
1447                         break;
1448                 }
1449         }
1450         if (pipefp == NULL)
1451                 return;
1452         fprintf(pipefp, "w\n");
1453         fprintf(pipefp, "q\n");
1454         fflush(pipefp);
1455         pclose(pipefp);
1456         ignore_signals();
1457         if (!check_only) {
1458                 if (move_file(TMPOUTNAME, outname) < 0) {
1459                         toutkeep = true;
1460                         chmod(TMPOUTNAME, filemode);
1461                 } else
1462                         chmod(outname, filemode);
1463         }
1464         set_signals(1);
1465 }
1466
1467 /*
1468  * Choose the name of the file to be patched based on POSIX rules.
1469  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1470  *       if the user specified --posix or set POSIXLY_CORRECT.
1471  */
1472 static char *
1473 posix_name(const struct file_name *names, bool assume_exists)
1474 {
1475         char *path = NULL;
1476         int i;
1477
1478         /*
1479          * POSIX states that the filename will be chosen from one
1480          * of the old, new and index names (in that order) if
1481          * the file exists relative to CWD after -p stripping.
1482          */
1483         for (i = 0; i < MAX_FILE; i++) {
1484                 if (names[i].path != NULL && names[i].exists) {
1485                         path = names[i].path;
1486                         break;
1487                 }
1488         }
1489         if (path == NULL && !assume_exists) {
1490                 /*
1491                  * No files found, look for something we can checkout from
1492                  * RCS/SCCS dirs.  Same order as above.
1493                  */
1494                 for (i = 0; i < MAX_FILE; i++) {
1495                         if (names[i].path != NULL &&
1496                             (path = checked_in(names[i].path)) != NULL)
1497                                 break;
1498                 }
1499                 /*
1500                  * Still no match?  Check to see if the diff could be creating
1501                  * a new file.
1502                  */
1503                 if (path == NULL && ok_to_create_file &&
1504                     names[NEW_FILE].path != NULL)
1505                         path = names[NEW_FILE].path;
1506         }
1507
1508         return path ? xstrdup(path) : NULL;
1509 }
1510
1511 static char *
1512 compare_names(const struct file_name *names, bool assume_exists, int phase)
1513 {
1514         size_t min_components, min_baselen, min_len, tmp;
1515         char *best = NULL;
1516         char *path;
1517         int i;
1518
1519         /*
1520          * The "best" name is the one with the fewest number of path
1521          * components, the shortest basename length, and the shortest
1522          * overall length (in that order).  We only use the Index: file
1523          * if neither of the old or new files could be intuited from
1524          * the diff header.
1525          */
1526         min_components = min_baselen = min_len = SIZE_MAX;
1527         for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1528                 path = names[i].path;
1529                 if (path == NULL ||
1530                     (phase == 1 && !names[i].exists && !assume_exists) ||
1531                     (phase == 2 && checked_in(path) == NULL))
1532                         continue;
1533                 if ((tmp = num_components(path)) > min_components)
1534                         continue;
1535                 if (tmp < min_components) {
1536                         min_components = tmp;
1537                         best = path;
1538                 }
1539                 if ((tmp = strlen(basename(path))) > min_baselen)
1540                         continue;
1541                 if (tmp < min_baselen) {
1542                         min_baselen = tmp;
1543                         best = path;
1544                 }
1545                 if ((tmp = strlen(path)) > min_len)
1546                         continue;
1547                 min_len = tmp;
1548                 best = path;
1549         }
1550         return best;
1551 }
1552
1553 /*
1554  * Choose the name of the file to be patched based the "best" one
1555  * available.
1556  */
1557 static char *
1558 best_name(const struct file_name *names, bool assume_exists)
1559 {
1560         char *best;
1561
1562         best = compare_names(names, assume_exists, 1);
1563         if (best == NULL) {
1564                 best = compare_names(names, assume_exists, 2);
1565                 /*
1566                  * Still no match?  Check to see if the diff could be creating
1567                  * a new file.
1568                  */
1569                 if (best == NULL && ok_to_create_file &&
1570                     names[NEW_FILE].path != NULL)
1571                         best = names[NEW_FILE].path;
1572         }
1573
1574         return best ? xstrdup(best) : NULL;
1575 }
1576
1577 static size_t
1578 num_components(const char *path)
1579 {
1580         size_t n;
1581         const char *cp;
1582
1583         for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1584                 while (*cp == '/')
1585                         cp++;           /* skip consecutive slashes */
1586         }
1587         return n;
1588 }
1589
1590 /*
1591  * Convert number at NPTR into LINENUM and save address of first
1592  * character that is not a digit in ENDPTR.  If conversion is not
1593  * possible, call fatal.
1594  */
1595 static LINENUM
1596 strtolinenum(char *nptr, char **endptr)
1597 {
1598         LINENUM rv;
1599         char c;
1600         char *p;
1601         const char *errstr;
1602
1603         for (p = nptr; isdigit((unsigned char)*p); p++)
1604                 ;
1605
1606         if (p == nptr)
1607                 malformed();
1608
1609         c = *p;
1610         *p = '\0';
1611
1612         rv = strtonum(nptr, 0, LINENUM_MAX, &errstr);
1613         if (errstr != NULL)
1614                 fatal("invalid line number at line %ld: `%s' is %s\n",
1615                     p_input_line, nptr, errstr);
1616
1617         *p = c;
1618         *endptr = p;
1619
1620         return rv;
1621 }