usr.bin/patch/pch.c

   1 /*
   2  * $OpenBSD: pch.c,v 1.35 2004/08/05 21:47:24 deraadt Exp $
   3  * $DragonFly: src/usr.bin/patch/pch.c,v 1.4 2006/04/18 22:11:35 joerg Exp $
   4  */
   5
   6 /*
   7  * patch - a program to apply diffs to original files
   8  *
   9  * Copyright 1986, Larry Wall
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following condition is met:
  13  * 1. Redistributions of source code must retain the above copyright notice,
  14  * this condition and the following disclaimer.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  17  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  18  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  19  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  20  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  22  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  23  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  29  * behaviour
  30  */
  31
  32 #include <sys/types.h>
  33 #include <sys/stat.h>
  34
  35 #include <ctype.h>
  36 #include <libgen.h>
  37 #include <limits.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <string.h>
  41 #include <unistd.h>
  42
  43 #include "common.h"
  44 #include "util.h"
  45 #include "pch.h"
  46 #include "pathnames.h"
  47
  48 /* Patch (diff listing) abstract type. */
  49
  50 static long     p_filesize;     /* size of the patch file */
  51 static LINENUM  p_first;        /* 1st line number */
  52 static LINENUM  p_newfirst;     /* 1st line number of replacement */
  53 static LINENUM  p_ptrn_lines;   /* # lines in pattern */
  54 static LINENUM  p_repl_lines;   /* # lines in replacement text */
  55 static LINENUM  p_end = -1;     /* last line in hunk */
  56 static LINENUM  p_max;          /* max allowed value of p_end */
  57 static LINENUM  p_context = 3;  /* # of context lines */
  58 static LINENUM  p_input_line = 0;       /* current line # from patch file */
  59 static char     **p_line = NULL;/* the text of the hunk */
  60 static short    *p_len = NULL;  /* length of each line */
  61 static char     *p_char = NULL; /* +, -, and ! */
  62 static int      hunkmax = INITHUNKMAX;  /* size of above arrays to begin with */
  63 static int      p_indent;       /* indent to patch */
  64 static LINENUM  p_base;         /* where to intuit this time */
  65 static LINENUM  p_bline;        /* line # of p_base */
  66 static LINENUM  p_start;        /* where intuit found a patch */
  67 static LINENUM  p_sline;        /* and the line number for it */
  68 static LINENUM  p_hunk_beg;     /* line number of current hunk */
  69 static LINENUM  p_efake = -1;   /* end of faked up lines--don't free */
  70 static LINENUM  p_bfake = -1;   /* beg of faked up lines */
  71 static FILE     *pfp = NULL;    /* patch file pointer */
  72 static char     *bestguess = NULL;      /* guess at correct filename */
  73
  74 static void     grow_hunkmax(void);
  75 static int      intuit_diff_type(void);
  76 static void     next_intuit_at(LINENUM, LINENUM);
  77 static void     skip_to(LINENUM, LINENUM);
  78 static char     *pgets(char *, int, FILE *);
  79 static char     *best_name(const struct file_name *, bool);
  80 static char     *posix_name(const struct file_name *, bool);
  81 static size_t   num_components(const 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
 106         if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
 107                 pfp = fopen(TMPPATNAME, "w");
 108                 if (pfp == NULL)
 109                         pfatal("can't create %s", TMPPATNAME);
 110                 while (fgets(buf, buf_len, stdin) != NULL)
 111                         fputs(buf, pfp);
 112                 fclose(pfp);
 113                 filename = TMPPATNAME;
 114         }
 115         pfp = fopen(filename, "r");
 116         if (pfp == NULL)
 117                 pfatal("patch file %s not found", filename);
 118         fstat(fileno(pfp), &filestat);
 119         p_filesize = filestat.st_size;
 120         next_intuit_at(0L, 1L); /* start at the beginning */
 121         set_hunkmax();
 122 }
 123
 124 /*
 125  * Make sure our dynamically realloced tables are malloced to begin with.
 126  */
 127 void
 128 set_hunkmax(void)
 129 {
 130         if (p_line == NULL)
 131                 p_line = malloc((size_t) hunkmax * sizeof(char *));
 132         if (p_len == NULL)
 133                 p_len = malloc((size_t) hunkmax * sizeof(short));
 134         if (p_char == NULL)
 135                 p_char = malloc((size_t) hunkmax * sizeof(char));
 136 }
 137
 138 /*
 139  * Enlarge the arrays containing the current hunk of patch.
 140  */
 141 static void
 142 grow_hunkmax(void)
 143 {
 144         int             new_hunkmax;
 145         char            **new_p_line;
 146         short           *new_p_len;
 147         char            *new_p_char;
 148
 149         new_hunkmax = hunkmax * 2;
 150
 151         if (p_line == NULL || p_len == NULL || p_char == NULL)
 152                 fatal("Internal memory allocation error\n");
 153
 154         new_p_line = realloc(p_line, new_hunkmax * sizeof(char *));
 155         if (new_p_line == NULL)
 156                 free(p_line);
 157
 158         new_p_len = realloc(p_len, new_hunkmax * sizeof(short));
 159         if (new_p_len == NULL)
 160                 free(p_len);
 161
 162         new_p_char = realloc(p_char, new_hunkmax * sizeof(char));
 163         if (new_p_char == NULL)
 164                 free(p_char);
 165
 166         p_char = new_p_char;
 167         p_len = new_p_len;
 168         p_line = new_p_line;
 169
 170         if (p_line != NULL && p_len != NULL && p_char != NULL) {
 171                 hunkmax = new_hunkmax;
 172                 return;
 173         }
 174
 175         if (!using_plan_a)
 176                 fatal("out of memory\n");
 177         out_of_mem = true;      /* whatever is null will be allocated again */
 178                                 /* from within plan_a(), of all places */
 179 }
 180
 181 /* True if the remainder of the patch file contains a diff of some sort. */
 182
 183 bool
 184 there_is_another_patch(void)
 185 {
 186         bool exists = false;
 187
 188         if (p_base != 0L && p_base >= p_filesize) {
 189                 if (verbose)
 190                         say("done\n");
 191                 return false;
 192         }
 193         if (verbose)
 194                 say("Hmm...");
 195         diff_type = intuit_diff_type();
 196         if (!diff_type) {
 197                 if (p_base != 0L) {
 198                         if (verbose)
 199                                 say("  Ignoring the trailing garbage.\ndone\n");
 200                 } else
 201                         say("  I can't seem to find a patch in there anywhere.\n");
 202                 return false;
 203         }
 204         if (verbose)
 205                 say("  %sooks like %s to me...\n",
 206                     (p_base == 0L ? "L" : "The next patch l"),
 207                     diff_type == UNI_DIFF ? "a unified diff" :
 208                     diff_type == CONTEXT_DIFF ? "a context diff" :
 209                 diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
 210                     diff_type == NORMAL_DIFF ? "a normal diff" :
 211                     "an ed script");
 212         if (p_indent && verbose)
 213                 say("(Patch is indented %d space%s.)\n", p_indent,
 214                     p_indent == 1 ? "" : "s");
 215         skip_to(p_start, p_sline);
 216         while (filearg[0] == NULL) {
 217                 if (force || batch) {
 218                         say("No file to patch.  Skipping...\n");
 219                         filearg[0] = savestr(bestguess);
 220                         skip_rest_of_patch = true;
 221                         return true;
 222                 }
 223                 ask("File to patch: ");
 224                 if (*buf != '\n') {
 225                         free(bestguess);
 226                         bestguess = savestr(buf);
 227                         filearg[0] = fetchname(buf, &exists, 0);
 228                 }
 229                 if (!exists) {
 230                         ask("No file found--skip this patch? [n] ");
 231                         if (*buf != 'y')
 232                                 continue;
 233                         if (verbose)
 234                                 say("Skipping patch...\n");
 235                         free(filearg[0]);
 236                         filearg[0] = fetchname(bestguess, &exists, 0);
 237                         skip_rest_of_patch = true;
 238                         return true;
 239                 }
 240         }
 241         return true;
 242 }
 243
 244 /* Determine what kind of diff is in the remaining part of the patch file. */
 245
 246 static int
 247 intuit_diff_type(void)
 248 {
 249         long    this_line = 0, previous_line;
 250         long    first_command_line = -1;
 251         LINENUM fcl_line = -1;
 252         bool    last_line_was_command = false, this_is_a_command = false;
 253         bool    stars_last_line = false, stars_this_line = false;
 254         char    *s, *t;
 255         int     indent, retval;
 256         struct file_name names[MAX_FILE];
 257
 258         memset(names, 0, sizeof(names));
 259         ok_to_create_file = false;
 260         fseek(pfp, p_base, SEEK_SET);
 261         p_input_line = p_bline - 1;
 262         for (;;) {
 263                 previous_line = this_line;
 264                 last_line_was_command = this_is_a_command;
 265                 stars_last_line = stars_this_line;
 266                 this_line = ftell(pfp);
 267                 indent = 0;
 268                 p_input_line++;
 269                 if (fgets(buf, buf_len, pfp) == NULL) {
 270                         if (first_command_line >= 0L) {
 271                                 /* nothing but deletes!? */
 272                                 p_start = first_command_line;
 273                                 p_sline = fcl_line;
 274                                 retval = ED_DIFF;
 275                                 goto scan_exit;
 276                         } else {
 277                                 p_start = this_line;
 278                                 p_sline = p_input_line;
 279                                 retval = 0;
 280                                 goto scan_exit;
 281                         }
 282                 }
 283                 for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
 284                         if (*s == '\t')
 285                                 indent += 8 - (indent % 8);
 286                         else
 287                                 indent++;
 288                 }
 289                 for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
 290                         ;
 291                 this_is_a_command = (isdigit((unsigned char)*s) &&
 292                     (*t == 'd' || *t == 'c' || *t == 'a'));
 293                 if (first_command_line < 0L && this_is_a_command) {
 294                         first_command_line = this_line;
 295                         fcl_line = p_input_line;
 296                         p_indent = indent;      /* assume this for now */
 297                 }
 298                 if (!stars_last_line && strnEQ(s, "*** ", 4))
 299                         names[OLD_FILE].path = fetchname(s + 4,
 300                             &names[OLD_FILE].exists, strippath);
 301                 else if (strnEQ(s, "--- ", 4))
 302                         names[NEW_FILE].path = fetchname(s + 4,
 303                             &names[NEW_FILE].exists, strippath);
 304                 else if (strnEQ(s, "+++ ", 4))
 305                         /* pretend it is the old name */
 306                         names[OLD_FILE].path = fetchname(s + 4,
 307                             &names[OLD_FILE].exists, strippath);
 308                 else if (strnEQ(s, "Index:", 6))
 309                         names[INDEX_FILE].path = fetchname(s + 6,
 310                             &names[INDEX_FILE].exists, strippath);
 311                 else if (strnEQ(s, "Prereq:", 7)) {
 312                         for (t = s + 7; isspace((unsigned char)*t); t++)
 313                                 ;
 314                         revision = savestr(t);
 315                         for (t = revision; *t && !isspace((unsigned char)*t); t++)
 316                                 ;
 317                         *t = '\0';
 318                         if (*revision == '\0') {
 319                                 free(revision);
 320                                 revision = NULL;
 321                         }
 322                 }
 323                 if ((!diff_type || diff_type == ED_DIFF) &&
 324                     first_command_line >= 0L &&
 325                     strEQ(s, ".\n")) {
 326                         p_indent = indent;
 327                         p_start = first_command_line;
 328                         p_sline = fcl_line;
 329                         retval = ED_DIFF;
 330                         goto scan_exit;
 331                 }
 332                 if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
 333                         if (strnEQ(s + 4, "0,0", 3))
 334                                 ok_to_create_file = true;
 335                         p_indent = indent;
 336                         p_start = this_line;
 337                         p_sline = p_input_line;
 338                         retval = UNI_DIFF;
 339                         goto scan_exit;
 340                 }
 341                 stars_this_line = strnEQ(s, "********", 8);
 342                 if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
 343                     strnEQ(s, "*** ", 4)) {
 344                         if (atol(s + 4) == 0)
 345                                 ok_to_create_file = true;
 346                         /*
 347                          * If this is a new context diff the character just
 348                          * before the newline is a '*'.
 349                          */
 350                         while (*s != '\n')
 351                                 s++;
 352                         p_indent = indent;
 353                         p_start = previous_line;
 354                         p_sline = p_input_line - 1;
 355                         retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
 356                         goto scan_exit;
 357                 }
 358                 if ((!diff_type || diff_type == NORMAL_DIFF) &&
 359                     last_line_was_command &&
 360                     (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
 361                         p_start = previous_line;
 362                         p_sline = p_input_line - 1;
 363                         p_indent = indent;
 364                         retval = NORMAL_DIFF;
 365                         goto scan_exit;
 366                 }
 367         }
 368 scan_exit:
 369         if (retval == UNI_DIFF) {
 370                 /* unswap old and new */
 371                 struct file_name tmp = names[OLD_FILE];
 372                 names[OLD_FILE] = names[NEW_FILE];
 373                 names[NEW_FILE] = tmp;
 374         }
 375         if (filearg[0] == NULL) {
 376                 if (posix)
 377                         filearg[0] = posix_name(names, ok_to_create_file);
 378                 else {
 379                         /* Ignore the Index: name for context diffs, like GNU */
 380                         if (names[OLD_FILE].path != NULL ||
 381                             names[NEW_FILE].path != NULL) {
 382                                 free(names[INDEX_FILE].path);
 383                                 names[INDEX_FILE].path = NULL;
 384                         }
 385                         filearg[0] = best_name(names, ok_to_create_file);
 386                 }
 387         }
 388
 389         free(bestguess);
 390         bestguess = NULL;
 391         if (filearg[0] != NULL)
 392                 bestguess = savestr(filearg[0]);
 393         else if (!ok_to_create_file) {
 394                 /*
 395                  * We don't want to create a new file but we need a
 396                  * filename to set bestguess.  Avoid setting filearg[0]
 397                  * so the file is not created automatically.
 398                  */
 399                 if (posix)
 400                         bestguess = posix_name(names, true);
 401                 else
 402                         bestguess = best_name(names, true);
 403         }
 404         free(names[OLD_FILE].path);
 405         free(names[NEW_FILE].path);
 406         free(names[INDEX_FILE].path);
 407         return retval;
 408 }
 409
 410 /*
 411  * Remember where this patch ends so we know where to start up again.
 412  */
 413 static void
 414 next_intuit_at(LINENUM file_pos, LINENUM file_line)
 415 {
 416         p_base = file_pos;
 417         p_bline = file_line;
 418 }
 419
 420 /*
 421  * Basically a verbose fseek() to the actual diff listing.
 422  */
 423 static void
 424 skip_to(LINENUM file_pos, LINENUM file_line)
 425 {
 426         char    *ret;
 427
 428         if (p_base > file_pos)
 429                 fatal("Internal error: seek %ld>%ld\n", p_base, file_pos);
 430         if (verbose && p_base < file_pos) {
 431                 fseek(pfp, p_base, SEEK_SET);
 432                 say("The text leading up to this was:\n--------------------------\n");
 433                 while (ftell(pfp) < file_pos) {
 434                         ret = fgets(buf, buf_len, pfp);
 435                         if (ret == NULL)
 436                                 fatal("Unexpected end of file\n");
 437                         say("|%s", buf);
 438                 }
 439                 say("--------------------------\n");
 440         } else
 441                 fseek(pfp, file_pos, SEEK_SET);
 442         p_input_line = file_line - 1;
 443 }
 444
 445 /* Make this a function for better debugging.  */
 446 static void
 447 malformed(void)
 448 {
 449         fatal("malformed patch at line %ld: %s", p_input_line, buf);
 450         /* about as informative as "Syntax error" in C */
 451 }
 452
 453 /*
 454  * True if the line has been discarded (i.e. it is a line saying
 455  *  "\ No newline at end of file".)
 456  */
 457 static bool
 458 remove_special_line(void)
 459 {
 460         int     c;
 461
 462         c = fgetc(pfp);
 463         if (c == '\\') {
 464                 do {
 465                         c = fgetc(pfp);
 466                 } while (c != EOF && c != '\n');
 467
 468                 return true;
 469         }
 470         if (c != EOF)
 471                 fseek(pfp, -1L, SEEK_CUR);
 472
 473         return false;
 474 }
 475
 476 /*
 477  * True if there is more of the current diff listing to process.
 478  */
 479 bool
 480 another_hunk(void)
 481 {
 482         long    line_beginning;                 /* file pos of the current line */
 483         LINENUM repl_beginning;                 /* index of --- line */
 484         LINENUM fillcnt;                        /* #lines of missing ptrn or repl */
 485         LINENUM fillsrc;                        /* index of first line to copy */
 486         LINENUM filldst;                        /* index of first missing line */
 487         bool    ptrn_spaces_eaten;              /* ptrn was slightly misformed */
 488         bool    repl_could_be_missing;          /* no + or ! lines in this hunk */
 489         bool    repl_missing;                   /* we are now backtracking */
 490         long    repl_backtrack_position;        /* file pos of first repl line */
 491         LINENUM repl_patch_line;                /* input line number for same */
 492         LINENUM ptrn_copiable;                  /* # of copiable lines in ptrn */
 493         char    *s, *ret;
 494         int     context = 0;
 495
 496         while (p_end >= 0) {
 497                 if (p_end == p_efake)
 498                         p_end = p_bfake;        /* don't free twice */
 499                 else
 500                         free(p_line[p_end]);
 501                 p_end--;
 502         }
 503         p_efake = -1;
 504
 505         p_max = hunkmax;        /* gets reduced when --- found */
 506         if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
 507                 line_beginning = ftell(pfp);
 508                 repl_beginning = 0;
 509                 fillcnt = 0;
 510                 fillsrc = 0;
 511                 filldst = 0;
 512                 ptrn_spaces_eaten = false;
 513                 repl_could_be_missing = true;
 514                 repl_missing = false;
 515                 repl_backtrack_position = 0;
 516                 repl_patch_line = 0;
 517                 ptrn_copiable = 0;
 518
 519                 ret = pgets(buf, buf_len, pfp);
 520                 p_input_line++;
 521                 if (ret == NULL || strnNE(buf, "********", 8)) {
 522                         next_intuit_at(line_beginning, p_input_line);
 523                         return false;
 524                 }
 525                 p_context = 100;
 526                 p_hunk_beg = p_input_line + 1;
 527                 while (p_end < p_max) {
 528                         line_beginning = ftell(pfp);
 529                         ret = pgets(buf, buf_len, pfp);
 530                         p_input_line++;
 531                         if (ret == NULL) {
 532                                 if (p_max - p_end < 4) {
 533                                         /* assume blank lines got chopped */
 534                                         strlcpy(buf, "  \n", buf_len);
 535                                 } else {
 536                                         if (repl_beginning && repl_could_be_missing) {
 537                                                 repl_missing = true;
 538                                                 goto hunk_done;
 539                                         }
 540                                         fatal("unexpected end of file in patch\n");
 541                                 }
 542                         }
 543                         p_end++;
 544                         if (p_end >= hunkmax)
 545                                 fatal("Internal error: hunk larger than hunk "
 546                                     "buffer size");
 547                         p_char[p_end] = *buf;
 548                         p_line[p_end] = NULL;
 549                         switch (*buf) {
 550                         case '*':
 551                                 if (strnEQ(buf, "********", 8)) {
 552                                         if (repl_beginning && repl_could_be_missing) {
 553                                                 repl_missing = true;
 554                                                 goto hunk_done;
 555                                         } else
 556                                                 fatal("unexpected end of hunk "
 557                                                     "at line %ld\n",
 558                                                     p_input_line);
 559                                 }
 560                                 if (p_end != 0) {
 561                                         if (repl_beginning && repl_could_be_missing) {
 562                                                 repl_missing = true;
 563                                                 goto hunk_done;
 564                                         }
 565                                         fatal("unexpected *** at line %ld: %s",
 566                                             p_input_line, buf);
 567                                 }
 568                                 context = 0;
 569                                 p_line[p_end] = savestr(buf);
 570                                 if (out_of_mem) {
 571                                         p_end--;
 572                                         return false;
 573                                 }
 574                                 for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 575                                         ;
 576                                 if (!*s)
 577                                         malformed();
 578                                 if (strnEQ(s, "0,0", 3))
 579                                         memmove(s, s + 2, strlen(s + 2) + 1);
 580                                 p_first = (LINENUM) atol(s);
 581                                 while (isdigit((unsigned char)*s))
 582                                         s++;
 583                                 if (*s == ',') {
 584                                         for (; *s && !isdigit((unsigned char)*s); s++)
 585                                                 ;
 586                                         if (!*s)
 587                                                 malformed();
 588                                         p_ptrn_lines = ((LINENUM) atol(s)) - p_first + 1;
 589                                 } else if (p_first)
 590                                         p_ptrn_lines = 1;
 591                                 else {
 592                                         p_ptrn_lines = 0;
 593                                         p_first = 1;
 594                                 }
 595
 596                                 /* we need this much at least */
 597                                 p_max = p_ptrn_lines + 6;
 598                                 while (p_max >= hunkmax)
 599                                         grow_hunkmax();
 600                                 p_max = hunkmax;
 601                                 break;
 602                         case '-':
 603                                 if (buf[1] == '-') {
 604                                         if (repl_beginning ||
 605                                             (p_end != p_ptrn_lines + 1 +
 606                                             (p_char[p_end - 1] == '\n'))) {
 607                                                 if (p_end == 1) {
 608                                                         /*
 609                                                          * `old' lines were omitted;
 610                                                          * set up to fill them in
 611                                                          * from 'new' context lines.
 612                                                          */
 613                                                         p_end = p_ptrn_lines + 1;
 614                                                         fillsrc = p_end + 1;
 615                                                         filldst = 1;
 616                                                         fillcnt = p_ptrn_lines;
 617                                                 } else {
 618                                                         if (repl_beginning) {
 619                                                                 if (repl_could_be_missing) {
 620                                                                         repl_missing = true;
 621                                                                         goto hunk_done;
 622                                                                 }
 623                                                                 fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
 624                                                                     p_input_line, p_hunk_beg + repl_beginning);
 625                                                         } else {
 626                                                                 fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
 627                                                                     (p_end <= p_ptrn_lines
 628                                                                     ? "Premature"
 629                                                                     : "Overdue"),
 630                                                                     p_input_line, p_hunk_beg);
 631                                                         }
 632                                                 }
 633                                         }
 634                                         repl_beginning = p_end;
 635                                         repl_backtrack_position = ftell(pfp);
 636                                         repl_patch_line = p_input_line;
 637                                         p_line[p_end] = savestr(buf);
 638                                         if (out_of_mem) {
 639                                                 p_end--;
 640                                                 return false;
 641                                         }
 642                                         p_char[p_end] = '=';
 643                                         for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 644                                                 ;
 645                                         if (!*s)
 646                                                 malformed();
 647                                         p_newfirst = (LINENUM) atol(s);
 648                                         while (isdigit((unsigned char)*s))
 649                                                 s++;
 650                                         if (*s == ',') {
 651                                                 for (; *s && !isdigit((unsigned char)*s); s++)
 652                                                         ;
 653                                                 if (!*s)
 654                                                         malformed();
 655                                                 p_repl_lines = ((LINENUM) atol(s)) -
 656                                                     p_newfirst + 1;
 657                                         } else if (p_newfirst)
 658                                                 p_repl_lines = 1;
 659                                         else {
 660                                                 p_repl_lines = 0;
 661                                                 p_newfirst = 1;
 662                                         }
 663                                         p_max = p_repl_lines + p_end;
 664                                         if (p_max > MAXHUNKSIZE)
 665                                                 fatal("hunk too large (%ld lines) at line %ld: %s",
 666                                                     p_max, p_input_line, buf);
 667                                         while (p_max >= hunkmax)
 668                                                 grow_hunkmax();
 669                                         if (p_repl_lines != ptrn_copiable &&
 670                                             (p_context != 0 || p_repl_lines != 1))
 671                                                 repl_could_be_missing = false;
 672                                         break;
 673                                 }
 674                                 goto change_line;
 675                         case '+':
 676                         case '!':
 677                                 repl_could_be_missing = false;
 678                 change_line:
 679                                 if (buf[1] == '\n' && canonicalize)
 680                                         strlcpy(buf + 1, " \n", buf_len - 1);
 681                                 if (!isspace((unsigned char)buf[1]) && buf[1] != '>' &&
 682                                     buf[1] != '<' &&
 683                                     repl_beginning && repl_could_be_missing) {
 684                                         repl_missing = true;
 685                                         goto hunk_done;
 686                                 }
 687                                 if (context >= 0) {
 688                                         if (context < p_context)
 689                                                 p_context = context;
 690                                         context = -1000;
 691                                 }
 692                                 p_line[p_end] = savestr(buf + 2);
 693                                 if (out_of_mem) {
 694                                         p_end--;
 695                                         return false;
 696                                 }
 697                                 if (p_end == p_ptrn_lines) {
 698                                         if (remove_special_line()) {
 699                                                 int     len;
 700
 701                                                 len = strlen(p_line[p_end]) - 1;
 702                                                 (p_line[p_end])[len] = 0;
 703                                         }
 704                                 }
 705                                 break;
 706                         case '\t':
 707                         case '\n':      /* assume the 2 spaces got eaten */
 708                                 if (repl_beginning && repl_could_be_missing &&
 709                                     (!ptrn_spaces_eaten ||
 710                                     diff_type == NEW_CONTEXT_DIFF)) {
 711                                         repl_missing = true;
 712                                         goto hunk_done;
 713                                 }
 714                                 p_line[p_end] = savestr(buf);
 715                                 if (out_of_mem) {
 716                                         p_end--;
 717                                         return false;
 718                                 }
 719                                 if (p_end != p_ptrn_lines + 1) {
 720                                         ptrn_spaces_eaten |= (repl_beginning != 0);
 721                                         context++;
 722                                         if (!repl_beginning)
 723                                                 ptrn_copiable++;
 724                                         p_char[p_end] = ' ';
 725                                 }
 726                                 break;
 727                         case ' ':
 728                                 if (!isspace((unsigned char)buf[1]) &&
 729                                     repl_beginning && repl_could_be_missing) {
 730                                         repl_missing = true;
 731                                         goto hunk_done;
 732                                 }
 733                                 context++;
 734                                 if (!repl_beginning)
 735                                         ptrn_copiable++;
 736                                 p_line[p_end] = savestr(buf + 2);
 737                                 if (out_of_mem) {
 738                                         p_end--;
 739                                         return false;
 740                                 }
 741                                 break;
 742                         default:
 743                                 if (repl_beginning && repl_could_be_missing) {
 744                                         repl_missing = true;
 745                                         goto hunk_done;
 746                                 }
 747                                 malformed();
 748                         }
 749                         /* set up p_len for strncmp() so we don't have to */
 750                         /* assume null termination */
 751                         if (p_line[p_end])
 752                                 p_len[p_end] = strlen(p_line[p_end]);
 753                         else
 754                                 p_len[p_end] = 0;
 755                 }
 756
 757 hunk_done:
 758                 if (p_end >= 0 && !repl_beginning)
 759                         fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
 760
 761                 if (repl_missing) {
 762
 763                         /* reset state back to just after --- */
 764                         p_input_line = repl_patch_line;
 765                         for (p_end--; p_end > repl_beginning; p_end--)
 766                                 free(p_line[p_end]);
 767                         fseek(pfp, repl_backtrack_position, SEEK_SET);
 768
 769                         /* redundant 'new' context lines were omitted - set */
 770                         /* up to fill them in from the old file context */
 771                         if (!p_context && p_repl_lines == 1) {
 772                                 p_repl_lines = 0;
 773                                 p_max--;
 774                         }
 775                         fillsrc = 1;
 776                         filldst = repl_beginning + 1;
 777                         fillcnt = p_repl_lines;
 778                         p_end = p_max;
 779                 } else if (!p_context && fillcnt == 1) {
 780                         /* the first hunk was a null hunk with no context */
 781                         /* and we were expecting one line -- fix it up. */
 782                         while (filldst < p_end) {
 783                                 p_line[filldst] = p_line[filldst + 1];
 784                                 p_char[filldst] = p_char[filldst + 1];
 785                                 p_len[filldst] = p_len[filldst + 1];
 786                                 filldst++;
 787                         }
 788 #if 0
 789                         repl_beginning--;       /* this doesn't need to be fixed */
 790 #endif
 791                         p_end--;
 792                         p_first++;      /* do append rather than insert */
 793                         fillcnt = 0;
 794                         p_ptrn_lines = 0;
 795                 }
 796                 if (diff_type == CONTEXT_DIFF &&
 797                     (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
 798                         if (verbose)
 799                                 say("%s\n%s\n%s\n",
 800                                     "(Fascinating--this is really a new-style context diff but without",
 801                                     "the telltale extra asterisks on the *** line that usually indicate",
 802                                     "the new style...)");
 803                         diff_type = NEW_CONTEXT_DIFF;
 804                 }
 805                 /* if there were omitted context lines, fill them in now */
 806                 if (fillcnt) {
 807                         p_bfake = filldst;      /* remember where not to free() */
 808                         p_efake = filldst + fillcnt - 1;
 809                         while (fillcnt-- > 0) {
 810                                 while (fillsrc <= p_end && p_char[fillsrc] != ' ')
 811                                         fillsrc++;
 812                                 if (fillsrc > p_end)
 813                                         fatal("replacement text or line numbers mangled in hunk at line %ld\n",
 814                                             p_hunk_beg);
 815                                 p_line[filldst] = p_line[fillsrc];
 816                                 p_char[filldst] = p_char[fillsrc];
 817                                 p_len[filldst] = p_len[fillsrc];
 818                                 fillsrc++;
 819                                 filldst++;
 820                         }
 821                         while (fillsrc <= p_end && fillsrc != repl_beginning &&
 822                             p_char[fillsrc] != ' ')
 823                                 fillsrc++;
 824 #ifdef DEBUGGING
 825                         if (debug & 64)
 826                                 printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
 827                                 fillsrc, filldst, repl_beginning, p_end + 1);
 828 #endif
 829                         if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
 830                                 malformed();
 831                         if (filldst != p_end + 1 && filldst != repl_beginning)
 832                                 malformed();
 833                 }
 834                 if (p_line[p_end] != NULL) {
 835                         if (remove_special_line()) {
 836                                 p_len[p_end] -= 1;
 837                                 (p_line[p_end])[p_len[p_end]] = 0;
 838                         }
 839                 }
 840         } else if (diff_type == UNI_DIFF) {
 841                 LINENUM fillold;        /* index of old lines */
 842                 LINENUM fillnew;        /* index of new lines */
 843                 char    ch;
 844
 845                 line_beginning = ftell(pfp); /* file pos of the current line */
 846                 ret = pgets(buf, buf_len, pfp);
 847                 p_input_line++;
 848                 if (ret == NULL || strnNE(buf, "@@ -", 4)) {
 849                         next_intuit_at(line_beginning, p_input_line);
 850                         return false;
 851                 }
 852                 s = buf + 4;
 853                 if (!*s)
 854                         malformed();
 855                 p_first = (LINENUM) atol(s);
 856                 while (isdigit((unsigned char)*s))
 857                         s++;
 858                 if (*s == ',') {
 859                         p_ptrn_lines = (LINENUM) atol(++s);
 860                         while (isdigit((unsigned char)*s))
 861                                 s++;
 862                 } else
 863                         p_ptrn_lines = 1;
 864                 if (*s == ' ')
 865                         s++;
 866                 if (*s != '+' || !*++s)
 867                         malformed();
 868                 p_newfirst = (LINENUM) atol(s);
 869                 while (isdigit((unsigned char)*s))
 870                         s++;
 871                 if (*s == ',') {
 872                         p_repl_lines = (LINENUM) atol(++s);
 873                         while (isdigit((unsigned char)*s))
 874                                 s++;
 875                 } else
 876                         p_repl_lines = 1;
 877                 if (*s == ' ')
 878                         s++;
 879                 if (*s != '@')
 880                         malformed();
 881                 if (!p_ptrn_lines)
 882                         p_first++;      /* do append rather than insert */
 883                 p_max = p_ptrn_lines + p_repl_lines + 1;
 884                 while (p_max >= hunkmax)
 885                         grow_hunkmax();
 886                 fillold = 1;
 887                 fillnew = fillold + p_ptrn_lines;
 888                 p_end = fillnew + p_repl_lines;
 889                 snprintf(buf, buf_len, "*** %ld,%ld ****\n", p_first,
 890                     p_first + p_ptrn_lines - 1);
 891                 p_line[0] = savestr(buf);
 892                 if (out_of_mem) {
 893                         p_end = -1;
 894                         return false;
 895                 }
 896                 p_char[0] = '*';
 897                 snprintf(buf, buf_len, "--- %ld,%ld ----\n", p_newfirst,
 898                     p_newfirst + p_repl_lines - 1);
 899                 p_line[fillnew] = savestr(buf);
 900                 if (out_of_mem) {
 901                         p_end = 0;
 902                         return false;
 903                 }
 904                 p_char[fillnew++] = '=';
 905                 p_context = 100;
 906                 context = 0;
 907                 p_hunk_beg = p_input_line + 1;
 908                 while (fillold <= p_ptrn_lines || fillnew <= p_end) {
 909                         line_beginning = ftell(pfp);
 910                         ret = pgets(buf, buf_len, pfp);
 911                         p_input_line++;
 912                         if (ret == NULL) {
 913                                 if (p_max - fillnew < 3) {
 914                                         /* assume blank lines got chopped */
 915                                         strlcpy(buf, " \n", buf_len);
 916                                 } else {
 917                                         fatal("unexpected end of file in patch\n");
 918                                 }
 919                         }
 920                         if (*buf == '\t' || *buf == '\n') {
 921                                 ch = ' ';       /* assume the space got eaten */
 922                                 s = savestr(buf);
 923                         } else {
 924                                 ch = *buf;
 925                                 s = savestr(buf + 1);
 926                         }
 927                         if (out_of_mem) {
 928                                 while (--fillnew > p_ptrn_lines)
 929                                         free(p_line[fillnew]);
 930                                 p_end = fillold - 1;
 931                                 return false;
 932                         }
 933                         switch (ch) {
 934                         case '-':
 935                                 if (fillold > p_ptrn_lines) {
 936                                         free(s);
 937                                         p_end = fillnew - 1;
 938                                         malformed();
 939                                 }
 940                                 p_char[fillold] = ch;
 941                                 p_line[fillold] = s;
 942                                 p_len[fillold++] = strlen(s);
 943                                 if (fillold > p_ptrn_lines) {
 944                                         if (remove_special_line()) {
 945                                                 p_len[fillold - 1] -= 1;
 946                                                 s[p_len[fillold - 1]] = 0;
 947                                         }
 948                                 }
 949                                 break;
 950                         case '=':
 951                                 ch = ' ';
 952                                 /* FALL THROUGH */
 953                         case ' ':
 954                                 if (fillold > p_ptrn_lines) {
 955                                         free(s);
 956                                         while (--fillnew > p_ptrn_lines)
 957                                                 free(p_line[fillnew]);
 958                                         p_end = fillold - 1;
 959                                         malformed();
 960                                 }
 961                                 context++;
 962                                 p_char[fillold] = ch;
 963                                 p_line[fillold] = s;
 964                                 p_len[fillold++] = strlen(s);
 965                                 s = savestr(s);
 966                                 if (out_of_mem) {
 967                                         while (--fillnew > p_ptrn_lines)
 968                                                 free(p_line[fillnew]);
 969                                         p_end = fillold - 1;
 970                                         return false;
 971                                 }
 972                                 if (fillold > p_ptrn_lines) {
 973                                         if (remove_special_line()) {
 974                                                 p_len[fillold - 1] -= 1;
 975                                                 s[p_len[fillold - 1]] = 0;
 976                                         }
 977                                 }
 978                                 /* FALL THROUGH */
 979                         case '+':
 980                                 if (fillnew > p_end) {
 981                                         free(s);
 982                                         while (--fillnew > p_ptrn_lines)
 983                                                 free(p_line[fillnew]);
 984                                         p_end = fillold - 1;
 985                                         malformed();
 986                                 }
 987                                 p_char[fillnew] = ch;
 988                                 p_line[fillnew] = s;
 989                                 p_len[fillnew++] = strlen(s);
 990                                 if (fillold > p_ptrn_lines) {
 991                                         if (remove_special_line()) {
 992                                                 p_len[fillnew - 1] -= 1;
 993                                                 s[p_len[fillnew - 1]] = 0;
 994                                         }
 995                                 }
 996                                 break;
 997                         default:
 998                                 p_end = fillnew;
 999                                 malformed();
1000                         }
1001                         if (ch != ' ' && context > 0) {
1002                                 if (context < p_context)
1003                                         p_context = context;
1004                                 context = -1000;
1005                         }
1006                 }               /* while */
1007         } else {                /* normal diff--fake it up */
1008                 char    hunk_type;
1009                 int     i;
1010                 LINENUM min, max;
1011
1012                 line_beginning = ftell(pfp);
1013                 p_context = 0;
1014                 ret = pgets(buf, buf_len, pfp);
1015                 p_input_line++;
1016                 if (ret == NULL || !isdigit((unsigned char)*buf)) {
1017                         next_intuit_at(line_beginning, p_input_line);
1018                         return false;
1019                 }
1020                 p_first = (LINENUM) atol(buf);
1021                 for (s = buf; isdigit((unsigned char)*s); s++)
1022                         ;
1023                 if (*s == ',') {
1024                         p_ptrn_lines = (LINENUM) atol(++s) - p_first + 1;
1025                         while (isdigit((unsigned char)*s))
1026                                 s++;
1027                 } else
1028                         p_ptrn_lines = (*s != 'a');
1029                 hunk_type = *s;
1030                 if (hunk_type == 'a')
1031                         p_first++;      /* do append rather than insert */
1032                 min = (LINENUM) atol(++s);
1033                 for (; isdigit((unsigned char)*s); s++)
1034                         ;
1035                 if (*s == ',')
1036                         max = (LINENUM) atol(++s);
1037                 else
1038                         max = min;
1039                 if (hunk_type == 'd')
1040                         min++;
1041                 p_end = p_ptrn_lines + 1 + max - min + 1;
1042                 if (p_end > MAXHUNKSIZE)
1043                         fatal("hunk too large (%ld lines) at line %ld: %s",
1044                             p_end, p_input_line, buf);
1045                 while (p_end >= hunkmax)
1046                         grow_hunkmax();
1047                 p_newfirst = min;
1048                 p_repl_lines = max - min + 1;
1049                 snprintf(buf, buf_len, "*** %ld,%ld\n", p_first,
1050                     p_first + p_ptrn_lines - 1);
1051                 p_line[0] = savestr(buf);
1052                 if (out_of_mem) {
1053                         p_end = -1;
1054                         return false;
1055                 }
1056                 p_char[0] = '*';
1057                 for (i = 1; i <= p_ptrn_lines; i++) {
1058                         ret = pgets(buf, buf_len, pfp);
1059                         p_input_line++;
1060                         if (ret == NULL)
1061                                 fatal("unexpected end of file in patch at line %ld\n",
1062                                     p_input_line);
1063                         if (*buf != '<')
1064                                 fatal("< expected at line %ld of patch\n",
1065                                     p_input_line);
1066                         p_line[i] = savestr(buf + 2);
1067                         if (out_of_mem) {
1068                                 p_end = i - 1;
1069                                 return false;
1070                         }
1071                         p_len[i] = strlen(p_line[i]);
1072                         p_char[i] = '-';
1073                 }
1074
1075                 if (remove_special_line()) {
1076                         p_len[i - 1] -= 1;
1077                         (p_line[i - 1])[p_len[i - 1]] = 0;
1078                 }
1079                 if (hunk_type == 'c') {
1080                         ret = pgets(buf, buf_len, pfp);
1081                         p_input_line++;
1082                         if (ret == NULL)
1083                                 fatal("unexpected end of file in patch at line %ld\n",
1084                                     p_input_line);
1085                         if (*buf != '-')
1086                                 fatal("--- expected at line %ld of patch\n",
1087                                     p_input_line);
1088                 }
1089                 snprintf(buf, buf_len, "--- %ld,%ld\n", min, max);
1090                 p_line[i] = savestr(buf);
1091                 if (out_of_mem) {
1092                         p_end = i - 1;
1093                         return false;
1094                 }
1095                 p_char[i] = '=';
1096                 for (i++; i <= p_end; i++) {
1097                         ret = pgets(buf, buf_len, pfp);
1098                         p_input_line++;
1099                         if (ret == NULL)
1100                                 fatal("unexpected end of file in patch at line %ld\n",
1101                                     p_input_line);
1102                         if (*buf != '>')
1103                                 fatal("> expected at line %ld of patch\n",
1104                                     p_input_line);
1105                         p_line[i] = savestr(buf + 2);
1106                         if (out_of_mem) {
1107                                 p_end = i - 1;
1108                                 return false;
1109                         }
1110                         p_len[i] = strlen(p_line[i]);
1111                         p_char[i] = '+';
1112                 }
1113
1114                 if (remove_special_line()) {
1115                         p_len[i - 1] -= 1;
1116                         (p_line[i - 1])[p_len[i - 1]] = 0;
1117                 }
1118         }
1119         if (reverse)            /* backwards patch? */
1120                 if (!pch_swap())
1121                         say("Not enough memory to swap next hunk!\n");
1122 #ifdef DEBUGGING
1123         if (debug & 2) {
1124                 int     i;
1125                 char    special;
1126
1127                 for (i = 0; i <= p_end; i++) {
1128                         if (i == p_ptrn_lines)
1129                                 special = '^';
1130                         else
1131                                 special = ' ';
1132                         fprintf(stderr, "%3d %c %c %s", i, p_char[i],
1133                             special, p_line[i]);
1134                         fflush(stderr);
1135                 }
1136         }
1137 #endif
1138         if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1139                 p_char[p_end + 1] = '^';        /* add a stopper for apply_hunk */
1140         return true;
1141 }
1142
1143 /*
1144  * Input a line from the patch file, worrying about indentation.
1145  */
1146 static char *
1147 pgets(char *bf, int sz, FILE *fp)
1148 {
1149         char    *s, *ret = fgets(bf, sz, fp);
1150         int     indent = 0;
1151
1152         if (p_indent && ret != NULL) {
1153                 for (s = buf;
1154                     indent < p_indent && (*s == ' ' || *s == '\t' || *s == 'X');
1155                     s++) {
1156                         if (*s == '\t')
1157                                 indent += 8 - (indent % 7);
1158                         else
1159                                 indent++;
1160                 }
1161                 if (buf != s && strlcpy(buf, s, buf_len) >= buf_len)
1162                         fatal("buffer too small in pgets()\n");
1163         }
1164         return ret;
1165 }
1166
1167 /*
1168  * Reverse the old and new portions of the current hunk.
1169  */
1170 bool
1171 pch_swap(void)
1172 {
1173         char    **tp_line;      /* the text of the hunk */
1174         short   *tp_len;        /* length of each line */
1175         char    *tp_char;       /* +, -, and ! */
1176         LINENUM i;
1177         LINENUM n;
1178         bool    blankline = false;
1179         char    *s;
1180
1181         i = p_first;
1182         p_first = p_newfirst;
1183         p_newfirst = i;
1184
1185         /* make a scratch copy */
1186
1187         tp_line = p_line;
1188         tp_len = p_len;
1189         tp_char = p_char;
1190         p_line = NULL;  /* force set_hunkmax to allocate again */
1191         p_len = NULL;
1192         p_char = NULL;
1193         set_hunkmax();
1194         if (p_line == NULL || p_len == NULL || p_char == NULL) {
1195
1196                 free(p_line);
1197                 p_line = tp_line;
1198                 free(p_len);
1199                 p_len = tp_len;
1200                 free(p_char);
1201                 p_char = tp_char;
1202                 return false;   /* not enough memory to swap hunk! */
1203         }
1204         /* now turn the new into the old */
1205
1206         i = p_ptrn_lines + 1;
1207         if (tp_char[i] == '\n') {       /* account for possible blank line */
1208                 blankline = true;
1209                 i++;
1210         }
1211         if (p_efake >= 0) {     /* fix non-freeable ptr range */
1212                 if (p_efake <= i)
1213                         n = p_end - i + 1;
1214                 else
1215                         n = -i;
1216                 p_efake += n;
1217                 p_bfake += n;
1218         }
1219         for (n = 0; i <= p_end; i++, n++) {
1220                 p_line[n] = tp_line[i];
1221                 p_char[n] = tp_char[i];
1222                 if (p_char[n] == '+')
1223                         p_char[n] = '-';
1224                 p_len[n] = tp_len[i];
1225         }
1226         if (blankline) {
1227                 i = p_ptrn_lines + 1;
1228                 p_line[n] = tp_line[i];
1229                 p_char[n] = tp_char[i];
1230                 p_len[n] = tp_len[i];
1231                 n++;
1232         }
1233         if (p_char[0] != '=')
1234                 fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1235                     p_input_line, p_char[0]);
1236         p_char[0] = '*';
1237         for (s = p_line[0]; *s; s++)
1238                 if (*s == '-')
1239                         *s = '*';
1240
1241         /* now turn the old into the new */
1242
1243         if (p_char[0] != '*')
1244                 fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1245                     p_input_line, p_char[0]);
1246         tp_char[0] = '=';
1247         for (s = tp_line[0]; *s; s++)
1248                 if (*s == '*')
1249                         *s = '-';
1250         for (i = 0; n <= p_end; i++, n++) {
1251                 p_line[n] = tp_line[i];
1252                 p_char[n] = tp_char[i];
1253                 if (p_char[n] == '-')
1254                         p_char[n] = '+';
1255                 p_len[n] = tp_len[i];
1256         }
1257
1258         if (i != p_ptrn_lines + 1)
1259                 fatal("Malformed patch at line %ld: expected %ld lines, "
1260                     "got %ld\n",
1261                     p_input_line, p_ptrn_lines + 1, i);
1262
1263         i = p_ptrn_lines;
1264         p_ptrn_lines = p_repl_lines;
1265         p_repl_lines = i;
1266
1267         free(tp_line);
1268         free(tp_len);
1269         free(tp_char);
1270
1271         return true;
1272 }
1273
1274 /*
1275  * Return the specified line position in the old file of the old context.
1276  */
1277 LINENUM
1278 pch_first(void)
1279 {
1280         return p_first;
1281 }
1282
1283 /*
1284  * Return the number of lines of old context.
1285  */
1286 LINENUM
1287 pch_ptrn_lines(void)
1288 {
1289         return p_ptrn_lines;
1290 }
1291
1292 /*
1293  * Return the probable line position in the new file of the first line.
1294  */
1295 LINENUM
1296 pch_newfirst(void)
1297 {
1298         return p_newfirst;
1299 }
1300
1301 /*
1302  * Return the number of lines in the replacement text including context.
1303  */
1304 LINENUM
1305 pch_repl_lines(void)
1306 {
1307         return p_repl_lines;
1308 }
1309
1310 /*
1311  * Return the number of lines in the whole hunk.
1312  */
1313 LINENUM
1314 pch_end(void)
1315 {
1316         return p_end;
1317 }
1318
1319 /*
1320  * Return the number of context lines before the first changed line.
1321  */
1322 LINENUM
1323 pch_context(void)
1324 {
1325         return p_context;
1326 }
1327
1328 /*
1329  * Return the length of a particular patch line.
1330  */
1331 short
1332 pch_line_len(LINENUM line)
1333 {
1334         return p_len[line];
1335 }
1336
1337 /*
1338  * Return the control character (+, -, *, !, etc) for a patch line.
1339  */
1340 char
1341 pch_char(LINENUM line)
1342 {
1343         return p_char[line];
1344 }
1345
1346 /*
1347  * Return a pointer to a particular patch line.
1348  */
1349 char *
1350 pfetch(LINENUM line)
1351 {
1352         return p_line[line];
1353 }
1354
1355 /*
1356  * Return where in the patch file this hunk began, for error messages.
1357  */
1358 LINENUM
1359 pch_hunk_beg(void)
1360 {
1361         return p_hunk_beg;
1362 }
1363
1364 /*
1365  * Apply an ed script by feeding ed itself.
1366  */
1367 void
1368 do_ed_script(void)
1369 {
1370         char    *t;
1371         long    beginning_of_this_line;
1372         FILE    *pipefp;
1373
1374         pipefp = NULL;
1375         if (!skip_rest_of_patch) {
1376                 if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1377                         unlink(TMPOUTNAME);
1378                         fatal("can't create temp file %s", TMPOUTNAME);
1379                 }
1380                 snprintf(buf, buf_len, "%s%s%s", _PATH_ED,
1381                     verbose ? " " : " -s ", TMPOUTNAME);
1382                 pipefp = popen(buf, "w");
1383         }
1384         for (;;) {
1385                 beginning_of_this_line = ftell(pfp);
1386                 if (pgets(buf, buf_len, pfp) == NULL) {
1387                         next_intuit_at(beginning_of_this_line, p_input_line);
1388                         break;
1389                 }
1390                 p_input_line++;
1391                 for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1392                         ;
1393                 /* POSIX defines allowed commands as {a,c,d,i,s} */
1394                 if (isdigit((unsigned char)*buf) && (*t == 'a' || *t == 'c' ||
1395                     *t == 'd' || *t == 'i' || *t == 's')) {
1396                         if (pipefp != NULL)
1397                                 fputs(buf, pipefp);
1398                         if (*t != 'd') {
1399                                 while (pgets(buf, buf_len, pfp) != NULL) {
1400                                         p_input_line++;
1401                                         if (pipefp != NULL)
1402                                                 fputs(buf, pipefp);
1403                                         if (strEQ(buf, ".\n"))
1404                                                 break;
1405                                 }
1406                         }
1407                 } else {
1408                         next_intuit_at(beginning_of_this_line, p_input_line);
1409                         break;
1410                 }
1411         }
1412         if (pipefp == NULL)
1413                 return;
1414         fprintf(pipefp, "w\n");
1415         fprintf(pipefp, "q\n");
1416         fflush(pipefp);
1417         pclose(pipefp);
1418         ignore_signals();
1419         if (!check_only) {
1420                 if (move_file(TMPOUTNAME, outname) < 0) {
1421                         toutkeep = true;
1422                         chmod(TMPOUTNAME, filemode);
1423                 } else
1424                         chmod(outname, filemode);
1425         }
1426         set_signals(1);
1427 }
1428
1429 /*
1430  * Choose the name of the file to be patched based on POSIX rules.
1431  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1432  *       if the user specified --posix or set POSIXLY_CORRECT.
1433  */
1434 static char *
1435 posix_name(const struct file_name *names, bool assume_exists)
1436 {
1437         char *path = NULL;
1438         int i;
1439
1440         /*
1441          * POSIX states that the filename will be chosen from one
1442          * of the old, new and index names (in that order) if
1443          * the file exists relative to CWD after -p stripping.
1444          */
1445         for (i = 0; i < MAX_FILE; i++) {
1446                 if (names[i].path != NULL && names[i].exists) {
1447                         path = names[i].path;
1448                         break;
1449                 }
1450         }
1451         if (path == NULL && !assume_exists) {
1452                 /*
1453                  * No files found, look for something we can checkout from
1454                  * RCS/SCCS dirs.  Same order as above.
1455                  */
1456                 for (i = 0; i < MAX_FILE; i++) {
1457                         if (names[i].path != NULL &&
1458                             (path = checked_in(names[i].path)) != NULL)
1459                                 break;
1460                 }
1461                 /*
1462                  * Still no match?  Check to see if the diff could be creating
1463                  * a new file.
1464                  */
1465                 if (path == NULL && ok_to_create_file &&
1466                     names[NEW_FILE].path != NULL)
1467                         path = names[NEW_FILE].path;
1468         }
1469
1470         return path ? savestr(path) : NULL;
1471 }
1472
1473 /*
1474  * Choose the name of the file to be patched based the "best" one
1475  * available.
1476  */
1477 static char *
1478 best_name(const struct file_name *names, bool assume_exists)
1479 {
1480         size_t min_components, min_baselen, min_len, tmp;
1481         char *best = NULL;
1482         int i;
1483
1484         /*
1485          * The "best" name is the one with the fewest number of path
1486          * components, the shortest basename length, and the shortest
1487          * overall length (in that order).  We only use the Index: file
1488          * if neither of the old or new files could be intuited from
1489          * the diff header.
1490          */
1491         min_components = min_baselen = min_len = SIZE_MAX;
1492         for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1493                 if (names[i].path == NULL ||
1494                     (!names[i].exists && !assume_exists))
1495                         continue;
1496                 if ((tmp = num_components(names[i].path)) > min_components)
1497                         continue;
1498                 min_components = tmp;
1499                 if ((tmp = strlen(basename(names[i].path))) > min_baselen)
1500                         continue;
1501                 min_baselen = tmp;
1502                 if ((tmp = strlen(names[i].path)) > min_len)
1503                         continue;
1504                 min_len = tmp;
1505                 best = names[i].path;
1506         }
1507         if (best == NULL) {
1508                 /*
1509                  * No files found, look for something we can checkout from
1510                  * RCS/SCCS dirs.  Logic is identical to that above...
1511                  */
1512                 min_components = min_baselen = min_len = SIZE_MAX;
1513                 for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1514                         if (names[i].path == NULL ||
1515                             checked_in(names[i].path) == NULL)
1516                                 continue;
1517                         if ((tmp = num_components(names[i].path)) > min_components)
1518                                 continue;
1519                         min_components = tmp;
1520                         if ((tmp = strlen(basename(names[i].path))) > min_baselen)
1521                                 continue;
1522                         min_baselen = tmp;
1523                         if ((tmp = strlen(names[i].path)) > min_len)
1524                                 continue;
1525                         min_len = tmp;
1526                         best = names[i].path;
1527                 }
1528                 /*
1529                  * Still no match?  Check to see if the diff could be creating
1530                  * a new file.
1531                  */
1532                 if (best == NULL && ok_to_create_file &&
1533                     names[NEW_FILE].path != NULL)
1534                         best = names[NEW_FILE].path;
1535         }
1536
1537         return best ? savestr(best) : NULL;
1538 }
1539
1540 static size_t
1541 num_components(const char *path)
1542 {
1543         size_t n;
1544         const char *cp;
1545
1546         for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1547                 while (*cp == '/')
1548                         cp++;           /* skip consecutive slashes */
1549         }
1550         return n;
1551 }