usr.bin/patch/pch.c

   1 /*-
   2  * Copyright 1986, Larry Wall
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following condition is met:
   6  * 1. Redistributions of source code must retain the above copyright notice,
   7  * this condition and the following disclaimer.
   8  *
   9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  10  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  11  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  12  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  13  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  14  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  15  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  16  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  17  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  18  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  19  * SUCH DAMAGE.
  20  *
  21  * patch - a program to apply diffs to original files
  22  *
  23  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  24  * behaviour
  25  *
  26  * $OpenBSD: pch.c,v 1.43 2014/11/18 17:03:35 tobias Exp $
  27  * $FreeBSD$
  28  */
  29
  30 #include <sys/types.h>
  31 #include <sys/stat.h>
  32
  33 #include <ctype.h>
  34 #include <libgen.h>
  35 #include <limits.h>
  36 #include <stdint.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42 #include "common.h"
  43 #include "util.h"
  44 #include "pch.h"
  45 #include "pathnames.h"
  46
  47 /* Patch (diff listing) abstract type. */
  48
  49 static off_t    p_filesize;     /* size of the patch file */
  50 static LINENUM  p_first;        /* 1st line number */
  51 static LINENUM  p_newfirst;     /* 1st line number of replacement */
  52 static LINENUM  p_ptrn_lines;   /* # lines in pattern */
  53 static LINENUM  p_repl_lines;   /* # lines in replacement text */
  54 static LINENUM  p_end = -1;     /* last line in hunk */
  55 static LINENUM  p_max;          /* max allowed value of p_end */
  56 static LINENUM  p_context = 3;  /* # of context lines */
  57 static LINENUM  p_input_line = 0;       /* current line # from patch file */
  58 static char     **p_line = NULL;/* the text of the hunk */
  59 static unsigned short   *p_len = NULL; /* length of each line */
  60 static char     *p_char = NULL; /* +, -, and ! */
  61 static int      hunkmax = INITHUNKMAX;  /* size of above arrays to begin with */
  62 static int      p_indent;       /* indent to patch */
  63 static off_t    p_base;         /* where to intuit this time */
  64 static LINENUM  p_bline;        /* line # of p_base */
  65 static off_t    p_start;        /* where intuit found a patch */
  66 static LINENUM  p_sline;        /* and the line number for it */
  67 static LINENUM  p_hunk_beg;     /* line number of current hunk */
  68 static LINENUM  p_efake = -1;   /* end of faked up lines--don't free */
  69 static LINENUM  p_bfake = -1;   /* beg of faked up lines */
  70 static FILE     *pfp = NULL;    /* patch file pointer */
  71 static char     *bestguess = NULL;      /* guess at correct filename */
  72
  73 char            *source_file;
  74
  75 static void     grow_hunkmax(void);
  76 static int      intuit_diff_type(void);
  77 static void     next_intuit_at(off_t, LINENUM);
  78 static void     skip_to(off_t, LINENUM);
  79 static size_t   pgets(bool _do_indent);
  80 static char     *best_name(const struct file_name *, bool);
  81 static char     *posix_name(const struct file_name *, bool);
  82 static size_t   num_components(const char *);
  83 static LINENUM  strtolinenum(char *, char **);
  84
  85 /*
  86  * Prepare to look for the next patch in the patch file.
  87  */
  88 void
  89 re_patch(void)
  90 {
  91         p_first = 0;
  92         p_newfirst = 0;
  93         p_ptrn_lines = 0;
  94         p_repl_lines = 0;
  95         p_end = (LINENUM) - 1;
  96         p_max = 0;
  97         p_indent = 0;
  98 }
  99
 100 /*
 101  * Open the patch file at the beginning of time.
 102  */
 103 void
 104 open_patch_file(const char *filename)
 105 {
 106         struct stat filestat;
 107         int nr, nw;
 108
 109         if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
 110                 pfp = fopen(TMPPATNAME, "w");
 111                 if (pfp == NULL)
 112                         pfatal("can't create %s", TMPPATNAME);
 113                 while ((nr = fread(buf, 1, buf_size, stdin)) > 0) {
 114                         nw = fwrite(buf, 1, nr, pfp);
 115                         if (nr != nw)
 116                                 pfatal("write error to %s", TMPPATNAME);
 117                 }
 118                 if (ferror(pfp) || fclose(pfp))
 119                         pfatal("can't write %s", TMPPATNAME);
 120                 filename = TMPPATNAME;
 121         }
 122         pfp = fopen(filename, "r");
 123         if (pfp == NULL)
 124                 pfatal("patch file %s not found", filename);
 125         if (fstat(fileno(pfp), &filestat))
 126                 pfatal("can't stat %s", filename);
 127         p_filesize = filestat.st_size;
 128         next_intuit_at(0, 1L);  /* start at the beginning */
 129         set_hunkmax();
 130 }
 131
 132 /*
 133  * Make sure our dynamically realloced tables are malloced to begin with.
 134  */
 135 void
 136 set_hunkmax(void)
 137 {
 138         if (p_line == NULL)
 139                 p_line = malloc(hunkmax * sizeof(char *));
 140         if (p_len == NULL)
 141                 p_len = malloc(hunkmax * sizeof(unsigned short));
 142         if (p_char == NULL)
 143                 p_char = malloc(hunkmax * sizeof(char));
 144 }
 145
 146 /*
 147  * Enlarge the arrays containing the current hunk of patch.
 148  */
 149 static void
 150 grow_hunkmax(void)
 151 {
 152         int new_hunkmax = hunkmax * 2;
 153
 154         if (p_line == NULL || p_len == NULL || p_char == NULL)
 155                 fatal("Internal memory allocation error\n");
 156
 157         p_line = reallocf(p_line, new_hunkmax * sizeof(char *));
 158         p_len = reallocf(p_len, new_hunkmax * sizeof(unsigned short));
 159         p_char = reallocf(p_char, new_hunkmax * sizeof(char));
 160
 161         if (p_line != NULL && p_len != NULL && p_char != NULL) {
 162                 hunkmax = new_hunkmax;
 163                 return;
 164         }
 165
 166         if (!using_plan_a)
 167                 fatal("out of memory\n");
 168         out_of_mem = true;      /* whatever is null will be allocated again */
 169                                 /* from within plan_a(), of all places */
 170 }
 171
 172 /* True if the remainder of the patch file contains a diff of some sort. */
 173
 174 bool
 175 there_is_another_patch(void)
 176 {
 177         bool exists = false;
 178
 179         if (p_base != 0 && p_base >= p_filesize) {
 180                 if (verbose)
 181                         say("done\n");
 182                 return false;
 183         }
 184         if (p_filesize == 0)
 185                 return false;
 186         nonempty_patchf_seen = true;
 187         if (verbose)
 188                 say("Hmm...");
 189         diff_type = intuit_diff_type();
 190         if (!diff_type) {
 191                 if (p_base != 0) {
 192                         if (verbose)
 193                                 say("  Ignoring the trailing garbage.\ndone\n");
 194                 } else
 195                         say("  I can't seem to find a patch in there anywhere.\n");
 196                 return false;
 197         }
 198         if (verbose)
 199                 say("  %sooks like %s to me...\n",
 200                     (p_base == 0 ? "L" : "The next patch l"),
 201                     diff_type == UNI_DIFF ? "a unified diff" :
 202                     diff_type == CONTEXT_DIFF ? "a context diff" :
 203                 diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
 204                     diff_type == NORMAL_DIFF ? "a normal diff" :
 205                     "an ed script");
 206         if (p_indent && verbose)
 207                 say("(Patch is indented %d space%s.)\n", p_indent,
 208                     p_indent == 1 ? "" : "s");
 209         skip_to(p_start, p_sline);
 210         while (filearg[0] == NULL) {
 211                 if (force || batch) {
 212                         say("No file to patch.  Skipping...\n");
 213                         filearg[0] = xstrdup(bestguess);
 214                         skip_rest_of_patch = true;
 215                         return true;
 216                 }
 217                 ask("File to patch: ");
 218                 if (*buf != '\n') {
 219                         free(bestguess);
 220                         bestguess = xstrdup(buf);
 221                         filearg[0] = fetchname(buf, &exists, 0);
 222                 }
 223                 /*
 224                  * fetchname can now return buf = NULL, exists = true, to
 225                  * indicate to the caller that /dev/null was specified.  Retain
 226                  * previous behavior for now until this can be better evaluted.
 227                  */
 228                 if (filearg[0] == NULL || !exists) {
 229                         int def_skip = *bestguess == '\0';
 230                         ask("No file found--skip this patch? [%c] ",
 231                             def_skip  ? 'y' : 'n');
 232                         if (*buf == 'n' || (!def_skip && *buf != 'y'))
 233                                 continue;
 234                         if (verbose)
 235                                 say("Skipping patch...\n");
 236                         free(filearg[0]);
 237                         filearg[0] = fetchname(bestguess, &exists, 0);
 238                         skip_rest_of_patch = true;
 239                         return true;
 240                 }
 241         }
 242         return true;
 243 }
 244
 245 static void
 246 p4_fetchname(struct file_name *name, char *str)
 247 {
 248         char *t, *h;
 249
 250         /* Skip leading whitespace. */
 251         while (isspace((unsigned char)*str))
 252                 str++;
 253
 254         /* Remove the file revision number. */
 255         for (t = str, h = NULL; *t != '\0' && !isspace((unsigned char)*t); t++)
 256                 if (*t == '#')
 257                         h = t;
 258         if (h != NULL)
 259                 *h = '\0';
 260
 261         name->path = fetchname(str, &name->exists, strippath);
 262 }
 263
 264 /* Determine what kind of diff is in the remaining part of the patch file. */
 265
 266 static int
 267 intuit_diff_type(void)
 268 {
 269         off_t   this_line = 0, previous_line;
 270         off_t   first_command_line = -1;
 271         LINENUM fcl_line = -1;
 272         bool    last_line_was_command = false, this_is_a_command = false;
 273         bool    stars_last_line = false, stars_this_line = false;
 274         char    *s, *t;
 275         int     indent, retval;
 276         struct file_name names[MAX_FILE];
 277         int     piece_of_git = 0;
 278
 279         memset(names, 0, sizeof(names));
 280         ok_to_create_file = false;
 281         fseeko(pfp, p_base, SEEK_SET);
 282         p_input_line = p_bline - 1;
 283         for (;;) {
 284                 previous_line = this_line;
 285                 last_line_was_command = this_is_a_command;
 286                 stars_last_line = stars_this_line;
 287                 this_line = ftello(pfp);
 288                 indent = 0;
 289                 p_input_line++;
 290                 if (pgets(false) == 0) {
 291                         if (first_command_line >= 0) {
 292                                 /* nothing but deletes!? */
 293                                 p_start = first_command_line;
 294                                 p_sline = fcl_line;
 295                                 retval = ED_DIFF;
 296                                 goto scan_exit;
 297                         } else {
 298                                 p_start = this_line;
 299                                 p_sline = p_input_line;
 300                                 retval = 0;
 301                                 goto scan_exit;
 302                         }
 303                 }
 304                 for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
 305                         if (*s == '\t')
 306                                 indent += 8 - (indent % 8);
 307                         else
 308                                 indent++;
 309                 }
 310                 for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
 311                         ;
 312                 this_is_a_command = (isdigit((unsigned char)*s) &&
 313                     (*t == 'd' || *t == 'c' || *t == 'a'));
 314                 if (first_command_line < 0 && this_is_a_command) {
 315                         first_command_line = this_line;
 316                         fcl_line = p_input_line;
 317                         p_indent = indent;      /* assume this for now */
 318                 }
 319                 if (!stars_last_line && strnEQ(s, "*** ", 4))
 320                         names[OLD_FILE].path = fetchname(s + 4,
 321                             &names[OLD_FILE].exists, strippath);
 322                 else if (strnEQ(s, "--- ", 4)) {
 323                         size_t off = 4;
 324                         if (piece_of_git && strippath == 957 &&
 325                             strnEQ(s, "--- a/", 6))
 326                                 off = 6;
 327                         names[NEW_FILE].path = fetchname(s + off,
 328                             &names[NEW_FILE].exists, strippath);
 329                 } else if (strnEQ(s, "+++ ", 4)) {
 330                         /* pretend it is the old name */
 331                         size_t off = 4;
 332                         if (piece_of_git && strippath == 957 &&
 333                             strnEQ(s, "+++ b/", 6))
 334                                 off = 6;
 335                         names[OLD_FILE].path = fetchname(s + off,
 336                             &names[OLD_FILE].exists, strippath);
 337                 } else if (strnEQ(s, "Index:", 6))
 338                         names[INDEX_FILE].path = fetchname(s + 6,
 339                             &names[INDEX_FILE].exists, strippath);
 340                 else if (strnEQ(s, "Prereq:", 7)) {
 341                         for (t = s + 7; isspace((unsigned char)*t); t++)
 342                                 ;
 343                         revision = xstrdup(t);
 344                         for (t = revision;
 345                              *t && !isspace((unsigned char)*t); t++)
 346                                 ;
 347                         *t = '\0';
 348                         if (*revision == '\0') {
 349                                 free(revision);
 350                                 revision = NULL;
 351                         }
 352                 } else if (strnEQ(s, "diff --git a/", 13)) {
 353                         /* Git-style diffs. */
 354                         piece_of_git = 1;
 355                 } else if (strnEQ(s, "==== ", 5)) {
 356                         /* Perforce-style diffs. */
 357                         if ((t = strstr(s + 5, " - ")) != NULL)
 358                                 p4_fetchname(&names[NEW_FILE], t + 3);
 359                         p4_fetchname(&names[OLD_FILE], s + 5);
 360                 }
 361                 if ((!diff_type || diff_type == ED_DIFF) &&
 362                     first_command_line >= 0 &&
 363                     strEQ(s, ".\n")) {
 364                         p_indent = indent;
 365                         p_start = first_command_line;
 366                         p_sline = fcl_line;
 367                         retval = ED_DIFF;
 368                         goto scan_exit;
 369                 }
 370                 if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
 371                         if (strnEQ(s + 4, "0,0", 3))
 372                                 ok_to_create_file = true;
 373                         p_indent = indent;
 374                         p_start = this_line;
 375                         p_sline = p_input_line;
 376                         retval = UNI_DIFF;
 377                         goto scan_exit;
 378                 }
 379                 stars_this_line = strnEQ(s, "********", 8);
 380                 if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
 381                     strnEQ(s, "*** ", 4)) {
 382                         if (strtolinenum(s + 4, &s) == 0)
 383                                 ok_to_create_file = true;
 384                         /*
 385                          * If this is a new context diff the character just
 386                          * at the end of the line is a '*'.
 387                          */
 388                         while (*s && *s != '\n')
 389                                 s++;
 390                         p_indent = indent;
 391                         p_start = previous_line;
 392                         p_sline = p_input_line - 1;
 393                         retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
 394                         goto scan_exit;
 395                 }
 396                 if ((!diff_type || diff_type == NORMAL_DIFF) &&
 397                     last_line_was_command &&
 398                     (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
 399                         p_start = previous_line;
 400                         p_sline = p_input_line - 1;
 401                         p_indent = indent;
 402                         retval = NORMAL_DIFF;
 403                         goto scan_exit;
 404                 }
 405         }
 406 scan_exit:
 407         if (retval == UNI_DIFF) {
 408                 /* unswap old and new */
 409                 struct file_name tmp = names[OLD_FILE];
 410                 names[OLD_FILE] = names[NEW_FILE];
 411                 names[NEW_FILE] = tmp;
 412         }
 413
 414         /* Invalidated */
 415         free(source_file);
 416         source_file = NULL;
 417
 418         if (retval != 0) {
 419                 /*
 420                  * If we've successfully determined a diff type, stored in
 421                  * retval, path == NULL means _PATH_DEVNULL if exists is set.
 422                  * Explicitly specify it here to make it easier to detect later
 423                  * on that we're actually creating a file and not that we've
 424                  * just goofed something up.
 425                  */
 426                 if (names[OLD_FILE].path != NULL)
 427                         source_file = xstrdup(names[OLD_FILE].path);
 428                 else if (names[OLD_FILE].exists)
 429                         source_file = xstrdup(_PATH_DEVNULL);
 430         }
 431         if (filearg[0] == NULL) {
 432                 if (posix)
 433                         filearg[0] = posix_name(names, ok_to_create_file);
 434                 else {
 435                         /* Ignore the Index: name for context diffs, like GNU */
 436                         if (names[OLD_FILE].path != NULL ||
 437                             names[NEW_FILE].path != NULL) {
 438                                 free(names[INDEX_FILE].path);
 439                                 names[INDEX_FILE].path = NULL;
 440                         }
 441                         filearg[0] = best_name(names, ok_to_create_file);
 442                 }
 443         }
 444
 445         free(bestguess);
 446         bestguess = NULL;
 447         if (filearg[0] != NULL)
 448                 bestguess = xstrdup(filearg[0]);
 449         else if (!ok_to_create_file) {
 450                 /*
 451                  * We don't want to create a new file but we need a
 452                  * filename to set bestguess.  Avoid setting filearg[0]
 453                  * so the file is not created automatically.
 454                  */
 455                 if (posix)
 456                         bestguess = posix_name(names, true);
 457                 else
 458                         bestguess = best_name(names, true);
 459         }
 460         free(names[OLD_FILE].path);
 461         free(names[NEW_FILE].path);
 462         free(names[INDEX_FILE].path);
 463         return retval;
 464 }
 465
 466 /*
 467  * Remember where this patch ends so we know where to start up again.
 468  */
 469 static void
 470 next_intuit_at(off_t file_pos, LINENUM file_line)
 471 {
 472         p_base = file_pos;
 473         p_bline = file_line;
 474 }
 475
 476 /*
 477  * Basically a verbose fseeko() to the actual diff listing.
 478  */
 479 static void
 480 skip_to(off_t file_pos, LINENUM file_line)
 481 {
 482         size_t  len;
 483
 484         if (p_base > file_pos)
 485                 fatal("Internal error: seek %lld>%lld\n",
 486                    (long long)p_base, (long long)file_pos);
 487         if (verbose && p_base < file_pos) {
 488                 fseeko(pfp, p_base, SEEK_SET);
 489                 say("The text leading up to this was:\n--------------------------\n");
 490                 while (ftello(pfp) < file_pos) {
 491                         len = pgets(false);
 492                         if (len == 0)
 493                                 fatal("Unexpected end of file\n");
 494                         say("|%s", buf);
 495                 }
 496                 say("--------------------------\n");
 497         } else
 498                 fseeko(pfp, file_pos, SEEK_SET);
 499         p_input_line = file_line - 1;
 500 }
 501
 502 /* Make this a function for better debugging.  */
 503 static void
 504 malformed(void)
 505 {
 506         fatal("malformed patch at line %ld: %s", p_input_line, buf);
 507         /* about as informative as "Syntax error" in C */
 508 }
 509
 510 /*
 511  * True if the line has been discarded (i.e. it is a line saying
 512  *  "\ No newline at end of file".)
 513  */
 514 static bool
 515 remove_special_line(void)
 516 {
 517         int     c;
 518
 519         c = fgetc(pfp);
 520         if (c == '\\') {
 521                 do {
 522                         c = fgetc(pfp);
 523                 } while (c != EOF && c != '\n');
 524
 525                 return true;
 526         }
 527         if (c != EOF)
 528                 fseeko(pfp, -1, SEEK_CUR);
 529
 530         return false;
 531 }
 532
 533 /*
 534  * True if there is more of the current diff listing to process.
 535  */
 536 bool
 537 another_hunk(void)
 538 {
 539         off_t   line_beginning;                 /* file pos of the current line */
 540         LINENUM repl_beginning;                 /* index of --- line */
 541         LINENUM fillcnt;                        /* #lines of missing ptrn or repl */
 542         LINENUM fillsrc;                        /* index of first line to copy */
 543         LINENUM filldst;                        /* index of first missing line */
 544         bool    ptrn_spaces_eaten;              /* ptrn was slightly malformed */
 545         bool    repl_could_be_missing;          /* no + or ! lines in this hunk */
 546         bool    repl_missing;                   /* we are now backtracking */
 547         off_t   repl_backtrack_position;        /* file pos of first repl line */
 548         LINENUM repl_patch_line;                /* input line number for same */
 549         LINENUM ptrn_copiable;                  /* # of copiable lines in ptrn */
 550         char    *s;
 551         size_t  len;
 552         int     context = 0;
 553
 554         while (p_end >= 0) {
 555                 if (p_end == p_efake)
 556                         p_end = p_bfake;        /* don't free twice */
 557                 else
 558                         free(p_line[p_end]);
 559                 p_end--;
 560         }
 561         p_efake = -1;
 562
 563         p_max = hunkmax;        /* gets reduced when --- found */
 564         if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
 565                 line_beginning = ftello(pfp);
 566                 repl_beginning = 0;
 567                 fillcnt = 0;
 568                 fillsrc = 0;
 569                 filldst = 0;
 570                 ptrn_spaces_eaten = false;
 571                 repl_could_be_missing = true;
 572                 repl_missing = false;
 573                 repl_backtrack_position = 0;
 574                 repl_patch_line = 0;
 575                 ptrn_copiable = 0;
 576
 577                 len = pgets(true);
 578                 p_input_line++;
 579                 if (len == 0 || strnNE(buf, "********", 8)) {
 580                         next_intuit_at(line_beginning, p_input_line);
 581                         return false;
 582                 }
 583                 p_context = 100;
 584                 p_hunk_beg = p_input_line + 1;
 585                 while (p_end < p_max) {
 586                         line_beginning = ftello(pfp);
 587                         len = pgets(true);
 588                         p_input_line++;
 589                         if (len == 0) {
 590                                 if (repl_beginning && repl_could_be_missing) {
 591                                         repl_missing = true;
 592                                         goto hunk_done;
 593                                 }
 594                                 fatal("unexpected end of file in patch\n");
 595                         }
 596                         p_end++;
 597                         if (p_end >= hunkmax)
 598                                 fatal("Internal error: hunk larger than hunk "
 599                                     "buffer size");
 600                         p_char[p_end] = *buf;
 601                         p_line[p_end] = NULL;
 602                         switch (*buf) {
 603                         case '*':
 604                                 if (strnEQ(buf, "********", 8)) {
 605                                         if (repl_beginning && repl_could_be_missing) {
 606                                                 repl_missing = true;
 607                                                 goto hunk_done;
 608                                         } else
 609                                                 fatal("unexpected end of hunk "
 610                                                     "at line %ld\n",
 611                                                     p_input_line);
 612                                 }
 613                                 if (p_end != 0) {
 614                                         if (repl_beginning && repl_could_be_missing) {
 615                                                 repl_missing = true;
 616                                                 goto hunk_done;
 617                                         }
 618                                         fatal("unexpected *** at line %ld: %s",
 619                                             p_input_line, buf);
 620                                 }
 621                                 context = 0;
 622                                 p_line[p_end] = savestr(buf);
 623                                 if (out_of_mem) {
 624                                         p_end--;
 625                                         return false;
 626                                 }
 627                                 for (s = buf;
 628                                      *s && !isdigit((unsigned char)*s); s++)
 629                                         ;
 630                                 if (!*s)
 631                                         malformed();
 632                                 if (strnEQ(s, "0,0", 3))
 633                                         memmove(s, s + 2, strlen(s + 2) + 1);
 634                                 p_first = strtolinenum(s, &s);
 635                                 if (*s == ',') {
 636                                         for (;
 637                                              *s && !isdigit((unsigned char)*s); s++)
 638                                                 ;
 639                                         if (!*s)
 640                                                 malformed();
 641                                         p_ptrn_lines = strtolinenum(s, &s) - p_first + 1;
 642                                         if (p_ptrn_lines < 0)
 643                                                 malformed();
 644                                 } else if (p_first)
 645                                         p_ptrn_lines = 1;
 646                                 else {
 647                                         p_ptrn_lines = 0;
 648                                         p_first = 1;
 649                                 }
 650                                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 651                                     p_ptrn_lines >= LINENUM_MAX - 6)
 652                                         malformed();
 653
 654                                 /* we need this much at least */
 655                                 p_max = p_ptrn_lines + 6;
 656                                 while (p_max >= hunkmax)
 657                                         grow_hunkmax();
 658                                 p_max = hunkmax;
 659                                 break;
 660                         case '-':
 661                                 if (buf[1] == '-') {
 662                                         if (repl_beginning ||
 663                                             (p_end != p_ptrn_lines + 1 +
 664                                             (p_char[p_end - 1] == '\n'))) {
 665                                                 if (p_end == 1) {
 666                                                         /*
 667                                                          * `old' lines were omitted;
 668                                                          * set up to fill them in
 669                                                          * from 'new' context lines.
 670                                                          */
 671                                                         p_end = p_ptrn_lines + 1;
 672                                                         fillsrc = p_end + 1;
 673                                                         filldst = 1;
 674                                                         fillcnt = p_ptrn_lines;
 675                                                 } else {
 676                                                         if (repl_beginning) {
 677                                                                 if (repl_could_be_missing) {
 678                                                                         repl_missing = true;
 679                                                                         goto hunk_done;
 680                                                                 }
 681                                                                 fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
 682                                                                     p_input_line, p_hunk_beg + repl_beginning);
 683                                                         } else {
 684                                                                 fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
 685                                                                     (p_end <= p_ptrn_lines
 686                                                                     ? "Premature"
 687                                                                     : "Overdue"),
 688                                                                     p_input_line, p_hunk_beg);
 689                                                         }
 690                                                 }
 691                                         }
 692                                         repl_beginning = p_end;
 693                                         repl_backtrack_position = ftello(pfp);
 694                                         repl_patch_line = p_input_line;
 695                                         p_line[p_end] = savestr(buf);
 696                                         if (out_of_mem) {
 697                                                 p_end--;
 698                                                 return false;
 699                                         }
 700                                         p_char[p_end] = '=';
 701                                         for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 702                                                 ;
 703                                         if (!*s)
 704                                                 malformed();
 705                                         p_newfirst = strtolinenum(s, &s);
 706                                         if (*s == ',') {
 707                                                 for (; *s && !isdigit((unsigned char)*s); s++)
 708                                                         ;
 709                                                 if (!*s)
 710                                                         malformed();
 711                                                 p_repl_lines = strtolinenum(s, &s) -
 712                                                     p_newfirst + 1;
 713                                                 if (p_repl_lines < 0)
 714                                                         malformed();
 715                                         } else if (p_newfirst)
 716                                                 p_repl_lines = 1;
 717                                         else {
 718                                                 p_repl_lines = 0;
 719                                                 p_newfirst = 1;
 720                                         }
 721                                         if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
 722                                             p_repl_lines >= LINENUM_MAX - p_end)
 723                                                 malformed();
 724                                         p_max = p_repl_lines + p_end;
 725                                         if (p_max > MAXHUNKSIZE)
 726                                                 fatal("hunk too large (%ld lines) at line %ld: %s",
 727                                                     p_max, p_input_line, buf);
 728                                         while (p_max >= hunkmax)
 729                                                 grow_hunkmax();
 730                                         if (p_repl_lines != ptrn_copiable &&
 731                                             (p_context != 0 || p_repl_lines != 1))
 732                                                 repl_could_be_missing = false;
 733                                         break;
 734                                 }
 735                                 goto change_line;
 736                         case '+':
 737                         case '!':
 738                                 repl_could_be_missing = false;
 739                 change_line:
 740                                 if (buf[1] == '\n' && canonicalize)
 741                                         strlcpy(buf + 1, " \n", buf_size - 1);
 742                                 if (!isspace((unsigned char)buf[1]) &&
 743                                     buf[1] != '>' && buf[1] != '<' &&
 744                                     repl_beginning && repl_could_be_missing) {
 745                                         repl_missing = true;
 746                                         goto hunk_done;
 747                                 }
 748                                 if (context >= 0) {
 749                                         if (context < p_context)
 750                                                 p_context = context;
 751                                         context = -1000;
 752                                 }
 753                                 p_line[p_end] = savestr(buf + 2);
 754                                 if (out_of_mem) {
 755                                         p_end--;
 756                                         return false;
 757                                 }
 758                                 if (p_end == p_ptrn_lines) {
 759                                         if (remove_special_line()) {
 760                                                 int     l;
 761
 762                                                 l = strlen(p_line[p_end]) - 1;
 763                                                 (p_line[p_end])[l] = 0;
 764                                         }
 765                                 }
 766                                 break;
 767                         case '\t':
 768                         case '\n':      /* assume the 2 spaces got eaten */
 769                                 if (repl_beginning && repl_could_be_missing &&
 770                                     (!ptrn_spaces_eaten ||
 771                                     diff_type == NEW_CONTEXT_DIFF)) {
 772                                         repl_missing = true;
 773                                         goto hunk_done;
 774                                 }
 775                                 p_line[p_end] = savestr(buf);
 776                                 if (out_of_mem) {
 777                                         p_end--;
 778                                         return false;
 779                                 }
 780                                 if (p_end != p_ptrn_lines + 1) {
 781                                         ptrn_spaces_eaten |= (repl_beginning != 0);
 782                                         context++;
 783                                         if (!repl_beginning)
 784                                                 ptrn_copiable++;
 785                                         p_char[p_end] = ' ';
 786                                 }
 787                                 break;
 788                         case ' ':
 789                                 if (!isspace((unsigned char)buf[1]) &&
 790                                     repl_beginning && repl_could_be_missing) {
 791                                         repl_missing = true;
 792                                         goto hunk_done;
 793                                 }
 794                                 context++;
 795                                 if (!repl_beginning)
 796                                         ptrn_copiable++;
 797                                 p_line[p_end] = savestr(buf + 2);
 798                                 if (out_of_mem) {
 799                                         p_end--;
 800                                         return false;
 801                                 }
 802                                 break;
 803                         default:
 804                                 if (repl_beginning && repl_could_be_missing) {
 805                                         repl_missing = true;
 806                                         goto hunk_done;
 807                                 }
 808                                 malformed();
 809                         }
 810                         /* set up p_len for strncmp() so we don't have to */
 811                         /* assume null termination */
 812                         if (p_line[p_end])
 813                                 p_len[p_end] = strlen(p_line[p_end]);
 814                         else
 815                                 p_len[p_end] = 0;
 816                 }
 817
 818 hunk_done:
 819                 if (p_end >= 0 && !repl_beginning)
 820                         fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
 821
 822                 if (repl_missing) {
 823
 824                         /* reset state back to just after --- */
 825                         p_input_line = repl_patch_line;
 826                         for (p_end--; p_end > repl_beginning; p_end--)
 827                                 free(p_line[p_end]);
 828                         fseeko(pfp, repl_backtrack_position, SEEK_SET);
 829
 830                         /* redundant 'new' context lines were omitted - set */
 831                         /* up to fill them in from the old file context */
 832                         if (!p_context && p_repl_lines == 1) {
 833                                 p_repl_lines = 0;
 834                                 p_max--;
 835                         }
 836                         fillsrc = 1;
 837                         filldst = repl_beginning + 1;
 838                         fillcnt = p_repl_lines;
 839                         p_end = p_max;
 840                 } else if (!p_context && fillcnt == 1) {
 841                         /* the first hunk was a null hunk with no context */
 842                         /* and we were expecting one line -- fix it up. */
 843                         while (filldst < p_end) {
 844                                 p_line[filldst] = p_line[filldst + 1];
 845                                 p_char[filldst] = p_char[filldst + 1];
 846                                 p_len[filldst] = p_len[filldst + 1];
 847                                 filldst++;
 848                         }
 849 #if 0
 850                         repl_beginning--;       /* this doesn't need to be fixed */
 851 #endif
 852                         p_end--;
 853                         p_first++;      /* do append rather than insert */
 854                         fillcnt = 0;
 855                         p_ptrn_lines = 0;
 856                 }
 857                 if (diff_type == CONTEXT_DIFF &&
 858                     (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
 859                         if (verbose)
 860                                 say("%s\n%s\n%s\n",
 861                                     "(Fascinating--this is really a new-style context diff but without",
 862                                     "the telltale extra asterisks on the *** line that usually indicate",
 863                                     "the new style...)");
 864                         diff_type = NEW_CONTEXT_DIFF;
 865                 }
 866                 /* if there were omitted context lines, fill them in now */
 867                 if (fillcnt) {
 868                         p_bfake = filldst;      /* remember where not to free() */
 869                         p_efake = filldst + fillcnt - 1;
 870                         while (fillcnt-- > 0) {
 871                                 while (fillsrc <= p_end && p_char[fillsrc] != ' ')
 872                                         fillsrc++;
 873                                 if (fillsrc > p_end)
 874                                         fatal("replacement text or line numbers mangled in hunk at line %ld\n",
 875                                             p_hunk_beg);
 876                                 p_line[filldst] = p_line[fillsrc];
 877                                 p_char[filldst] = p_char[fillsrc];
 878                                 p_len[filldst] = p_len[fillsrc];
 879                                 fillsrc++;
 880                                 filldst++;
 881                         }
 882                         while (fillsrc <= p_end && fillsrc != repl_beginning &&
 883                             p_char[fillsrc] != ' ')
 884                                 fillsrc++;
 885 #ifdef DEBUGGING
 886                         if (debug & 64)
 887                                 printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
 888                                 fillsrc, filldst, repl_beginning, p_end + 1);
 889 #endif
 890                         if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
 891                                 malformed();
 892                         if (filldst != p_end + 1 && filldst != repl_beginning)
 893                                 malformed();
 894                 }
 895                 if (p_line[p_end] != NULL) {
 896                         if (remove_special_line()) {
 897                                 p_len[p_end] -= 1;
 898                                 (p_line[p_end])[p_len[p_end]] = 0;
 899                         }
 900                 }
 901         } else if (diff_type == UNI_DIFF) {
 902                 LINENUM fillold;        /* index of old lines */
 903                 LINENUM fillnew;        /* index of new lines */
 904                 char    ch;
 905
 906                 line_beginning = ftello(pfp); /* file pos of the current line */
 907                 len = pgets(true);
 908                 p_input_line++;
 909                 if (len == 0 || strnNE(buf, "@@ -", 4)) {
 910                         next_intuit_at(line_beginning, p_input_line);
 911                         return false;
 912                 }
 913                 s = buf + 4;
 914                 if (!*s)
 915                         malformed();
 916                 p_first = strtolinenum(s, &s);
 917                 if (*s == ',') {
 918                         p_ptrn_lines = strtolinenum(s + 1, &s);
 919                 } else
 920                         p_ptrn_lines = 1;
 921                 if (*s == ' ')
 922                         s++;
 923                 if (*s != '+' || !*++s)
 924                         malformed();
 925                 p_newfirst = strtolinenum(s, &s);
 926                 if (*s == ',') {
 927                         p_repl_lines = strtolinenum(s + 1, &s);
 928                 } else
 929                         p_repl_lines = 1;
 930                 if (*s == ' ')
 931                         s++;
 932                 if (*s != '@')
 933                         malformed();
 934                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 935                     p_newfirst > LINENUM_MAX - p_repl_lines ||
 936                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
 937                         malformed();
 938                 if (!p_ptrn_lines)
 939                         p_first++;      /* do append rather than insert */
 940                 p_max = p_ptrn_lines + p_repl_lines + 1;
 941                 while (p_max >= hunkmax)
 942                         grow_hunkmax();
 943                 fillold = 1;
 944                 fillnew = fillold + p_ptrn_lines;
 945                 p_end = fillnew + p_repl_lines;
 946                 snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
 947                     p_first + p_ptrn_lines - 1);
 948                 p_line[0] = savestr(buf);
 949                 if (out_of_mem) {
 950                         p_end = -1;
 951                         return false;
 952                 }
 953                 p_char[0] = '*';
 954                 snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
 955                     p_newfirst + p_repl_lines - 1);
 956                 p_line[fillnew] = savestr(buf);
 957                 if (out_of_mem) {
 958                         p_end = 0;
 959                         return false;
 960                 }
 961                 p_char[fillnew++] = '=';
 962                 p_context = 100;
 963                 context = 0;
 964                 p_hunk_beg = p_input_line + 1;
 965                 while (fillold <= p_ptrn_lines || fillnew <= p_end) {
 966                         line_beginning = ftello(pfp);
 967                         len = pgets(true);
 968                         p_input_line++;
 969                         if (len == 0) {
 970                                 if (p_max - fillnew < 3) {
 971                                         /* assume blank lines got chopped */
 972                                         strlcpy(buf, " \n", buf_size);
 973                                 } else {
 974                                         fatal("unexpected end of file in patch\n");
 975                                 }
 976                         }
 977                         if (*buf == '\t' || *buf == '\n') {
 978                                 ch = ' ';       /* assume the space got eaten */
 979                                 s = savestr(buf);
 980                         } else {
 981                                 ch = *buf;
 982                                 s = savestr(buf + 1);
 983                         }
 984                         if (out_of_mem) {
 985                                 while (--fillnew > p_ptrn_lines)
 986                                         free(p_line[fillnew]);
 987                                 p_end = fillold - 1;
 988                                 return false;
 989                         }
 990                         switch (ch) {
 991                         case '-':
 992                                 if (fillold > p_ptrn_lines) {
 993                                         free(s);
 994                                         p_end = fillnew - 1;
 995                                         malformed();
 996                                 }
 997                                 p_char[fillold] = ch;
 998                                 p_line[fillold] = s;
 999                                 p_len[fillold++] = strlen(s);
1000                                 if (fillold > p_ptrn_lines) {
1001                                         if (remove_special_line()) {
1002                                                 p_len[fillold - 1] -= 1;
1003                                                 s[p_len[fillold - 1]] = 0;
1004                                         }
1005                                 }
1006                                 break;
1007                         case '=':
1008                                 ch = ' ';
1009                                 /* FALL THROUGH */
1010                         case ' ':
1011                                 if (fillold > p_ptrn_lines) {
1012                                         free(s);
1013                                         while (--fillnew > p_ptrn_lines)
1014                                                 free(p_line[fillnew]);
1015                                         p_end = fillold - 1;
1016                                         malformed();
1017                                 }
1018                                 context++;
1019                                 p_char[fillold] = ch;
1020                                 p_line[fillold] = s;
1021                                 p_len[fillold++] = strlen(s);
1022                                 s = savestr(s);
1023                                 if (out_of_mem) {
1024                                         while (--fillnew > p_ptrn_lines)
1025                                                 free(p_line[fillnew]);
1026                                         p_end = fillold - 1;
1027                                         return false;
1028                                 }
1029                                 if (fillold > p_ptrn_lines) {
1030                                         if (remove_special_line()) {
1031                                                 p_len[fillold - 1] -= 1;
1032                                                 s[p_len[fillold - 1]] = 0;
1033                                         }
1034                                 }
1035                                 /* FALL THROUGH */
1036                         case '+':
1037                                 if (fillnew > p_end) {
1038                                         free(s);
1039                                         while (--fillnew > p_ptrn_lines)
1040                                                 free(p_line[fillnew]);
1041                                         p_end = fillold - 1;
1042                                         malformed();
1043                                 }
1044                                 p_char[fillnew] = ch;
1045                                 p_line[fillnew] = s;
1046                                 p_len[fillnew++] = strlen(s);
1047                                 if (fillold > p_ptrn_lines) {
1048                                         if (remove_special_line()) {
1049                                                 p_len[fillnew - 1] -= 1;
1050                                                 s[p_len[fillnew - 1]] = 0;
1051                                         }
1052                                 }
1053                                 break;
1054                         default:
1055                                 p_end = fillnew;
1056                                 malformed();
1057                         }
1058                         if (ch != ' ' && context > 0) {
1059                                 if (context < p_context)
1060                                         p_context = context;
1061                                 context = -1000;
1062                         }
1063                 }               /* while */
1064         } else {                /* normal diff--fake it up */
1065                 char    hunk_type;
1066                 int     i;
1067                 LINENUM min, max;
1068
1069                 line_beginning = ftello(pfp);
1070                 p_context = 0;
1071                 len = pgets(true);
1072                 p_input_line++;
1073                 if (len == 0 || !isdigit((unsigned char)*buf)) {
1074                         next_intuit_at(line_beginning, p_input_line);
1075                         return false;
1076                 }
1077                 p_first = strtolinenum(buf, &s);
1078                 if (*s == ',') {
1079                         p_ptrn_lines = strtolinenum(s + 1, &s) - p_first + 1;
1080                         if (p_ptrn_lines < 0)
1081                                 malformed();
1082                 } else
1083                         p_ptrn_lines = (*s != 'a');
1084                 hunk_type = *s;
1085                 if (hunk_type == 'a')
1086                         p_first++;      /* do append rather than insert */
1087                 min = strtolinenum(s + 1, &s);
1088                 if (*s == ',')
1089                         max = strtolinenum(s + 1, &s);
1090                 else
1091                         max = min;
1092                 if (min < 0 || min > max || max - min == LINENUM_MAX)
1093                         malformed();
1094                 if (hunk_type == 'd')
1095                         min++;
1096                 p_newfirst = min;
1097                 p_repl_lines = max - min + 1;
1098                 if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1099                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1100                         malformed();
1101                 p_end = p_ptrn_lines + p_repl_lines + 1;
1102                 if (p_end > MAXHUNKSIZE)
1103                         fatal("hunk too large (%ld lines) at line %ld: %s",
1104                             p_end, p_input_line, buf);
1105                 while (p_end >= hunkmax)
1106                         grow_hunkmax();
1107                 snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1108                     p_first + p_ptrn_lines - 1);
1109                 p_line[0] = savestr(buf);
1110                 if (out_of_mem) {
1111                         p_end = -1;
1112                         return false;
1113                 }
1114                 p_char[0] = '*';
1115                 for (i = 1; i <= p_ptrn_lines; i++) {
1116                         len = pgets(true);
1117                         p_input_line++;
1118                         if (len == 0)
1119                                 fatal("unexpected end of file in patch at line %ld\n",
1120                                     p_input_line);
1121                         if (*buf != '<')
1122                                 fatal("< expected at line %ld of patch\n",
1123                                     p_input_line);
1124                         p_line[i] = savestr(buf + 2);
1125                         if (out_of_mem) {
1126                                 p_end = i - 1;
1127                                 return false;
1128                         }
1129                         p_len[i] = strlen(p_line[i]);
1130                         p_char[i] = '-';
1131                 }
1132
1133                 if (remove_special_line()) {
1134                         p_len[i - 1] -= 1;
1135                         (p_line[i - 1])[p_len[i - 1]] = 0;
1136                 }
1137                 if (hunk_type == 'c') {
1138                         len = pgets(true);
1139                         p_input_line++;
1140                         if (len == 0)
1141                                 fatal("unexpected end of file in patch at line %ld\n",
1142                                     p_input_line);
1143                         if (*buf != '-')
1144                                 fatal("--- expected at line %ld of patch\n",
1145                                     p_input_line);
1146                 }
1147                 snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1148                 p_line[i] = savestr(buf);
1149                 if (out_of_mem) {
1150                         p_end = i - 1;
1151                         return false;
1152                 }
1153                 p_char[i] = '=';
1154                 for (i++; i <= p_end; i++) {
1155                         len = pgets(true);
1156                         p_input_line++;
1157                         if (len == 0)
1158                                 fatal("unexpected end of file in patch at line %ld\n",
1159                                     p_input_line);
1160                         if (*buf != '>')
1161                                 fatal("> expected at line %ld of patch\n",
1162                                     p_input_line);
1163                         /* Don't overrun if we don't have enough line */
1164                         if (len > 2)
1165                                 p_line[i] = savestr(buf + 2);
1166                         else
1167                                 p_line[i] = savestr("");
1168
1169                         if (out_of_mem) {
1170                                 p_end = i - 1;
1171                                 return false;
1172                         }
1173                         p_len[i] = strlen(p_line[i]);
1174                         p_char[i] = '+';
1175                 }
1176
1177                 if (remove_special_line()) {
1178                         p_len[i - 1] -= 1;
1179                         (p_line[i - 1])[p_len[i - 1]] = 0;
1180                 }
1181         }
1182         if (reverse)            /* backwards patch? */
1183                 if (!pch_swap())
1184                         say("Not enough memory to swap next hunk!\n");
1185 #ifdef DEBUGGING
1186         if (debug & 2) {
1187                 LINENUM i;
1188                 char    special;
1189
1190                 for (i = 0; i <= p_end; i++) {
1191                         if (i == p_ptrn_lines)
1192                                 special = '^';
1193                         else
1194                                 special = ' ';
1195                         fprintf(stderr, "%3ld %c %c %s", i, p_char[i],
1196                             special, p_line[i]);
1197                         fflush(stderr);
1198                 }
1199         }
1200 #endif
1201         if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1202                 p_char[p_end + 1] = '^';        /* add a stopper for apply_hunk */
1203         return true;
1204 }
1205
1206 /*
1207  * Input a line from the patch file.
1208  * Worry about indentation if do_indent is true.
1209  * The line is read directly into the buf global variable which
1210  * is resized if necessary in order to hold the complete line.
1211  * Returns the number of characters read including the terminating
1212  * '\n', if any.
1213  */
1214 size_t
1215 pgets(bool do_indent)
1216 {
1217         char *line;
1218         size_t len;
1219         int indent = 0, skipped = 0;
1220
1221         line = fgetln(pfp, &len);
1222         if (line != NULL) {
1223                 if (len + 1 > buf_size) {
1224                         while (len + 1 > buf_size)
1225                                 buf_size *= 2;
1226                         free(buf);
1227                         buf = malloc(buf_size);
1228                         if (buf == NULL)
1229                                 fatal("out of memory\n");
1230                 }
1231                 if (do_indent == 1 && p_indent) {
1232                         for (;
1233                             indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1234                             line++, skipped++) {
1235                                 if (*line == '\t')
1236                                         indent += 8 - (indent %7);
1237                                 else
1238                                         indent++;
1239                         }
1240                 }
1241                 memcpy(buf, line, len - skipped);
1242                 buf[len - skipped] = '\0';
1243         }
1244         return len;
1245 }
1246
1247
1248 /*
1249  * Reverse the old and new portions of the current hunk.
1250  */
1251 bool
1252 pch_swap(void)
1253 {
1254         char    **tp_line;      /* the text of the hunk */
1255         unsigned short  *tp_len;/* length of each line */
1256         char    *tp_char;       /* +, -, and ! */
1257         LINENUM i;
1258         LINENUM n;
1259         bool    blankline = false;
1260         char    *s;
1261
1262         i = p_first;
1263         p_first = p_newfirst;
1264         p_newfirst = i;
1265
1266         /* make a scratch copy */
1267
1268         tp_line = p_line;
1269         tp_len = p_len;
1270         tp_char = p_char;
1271         p_line = NULL;  /* force set_hunkmax to allocate again */
1272         p_len = NULL;
1273         p_char = NULL;
1274         set_hunkmax();
1275         if (p_line == NULL || p_len == NULL || p_char == NULL) {
1276
1277                 free(p_line);
1278                 p_line = tp_line;
1279                 free(p_len);
1280                 p_len = tp_len;
1281                 free(p_char);
1282                 p_char = tp_char;
1283                 return false;   /* not enough memory to swap hunk! */
1284         }
1285         /* now turn the new into the old */
1286
1287         i = p_ptrn_lines + 1;
1288         if (tp_char[i] == '\n') {       /* account for possible blank line */
1289                 blankline = true;
1290                 i++;
1291         }
1292         if (p_efake >= 0) {     /* fix non-freeable ptr range */
1293                 if (p_efake <= i)
1294                         n = p_end - i + 1;
1295                 else
1296                         n = -i;
1297                 p_efake += n;
1298                 p_bfake += n;
1299         }
1300         for (n = 0; i <= p_end; i++, n++) {
1301                 p_line[n] = tp_line[i];
1302                 p_char[n] = tp_char[i];
1303                 if (p_char[n] == '+')
1304                         p_char[n] = '-';
1305                 p_len[n] = tp_len[i];
1306         }
1307         if (blankline) {
1308                 i = p_ptrn_lines + 1;
1309                 p_line[n] = tp_line[i];
1310                 p_char[n] = tp_char[i];
1311                 p_len[n] = tp_len[i];
1312                 n++;
1313         }
1314         if (p_char[0] != '=')
1315                 fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1316                     p_input_line, p_char[0]);
1317         p_char[0] = '*';
1318         for (s = p_line[0]; *s; s++)
1319                 if (*s == '-')
1320                         *s = '*';
1321
1322         /* now turn the old into the new */
1323
1324         if (p_char[0] != '*')
1325                 fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1326                     p_input_line, p_char[0]);
1327         tp_char[0] = '=';
1328         for (s = tp_line[0]; *s; s++)
1329                 if (*s == '*')
1330                         *s = '-';
1331         for (i = 0; n <= p_end; i++, n++) {
1332                 p_line[n] = tp_line[i];
1333                 p_char[n] = tp_char[i];
1334                 if (p_char[n] == '-')
1335                         p_char[n] = '+';
1336                 p_len[n] = tp_len[i];
1337         }
1338
1339         if (i != p_ptrn_lines + 1)
1340                 fatal("Malformed patch at line %ld: expected %ld lines, "
1341                     "got %ld\n",
1342                     p_input_line, p_ptrn_lines + 1, i);
1343
1344         i = p_ptrn_lines;
1345         p_ptrn_lines = p_repl_lines;
1346         p_repl_lines = i;
1347
1348         free(tp_line);
1349         free(tp_len);
1350         free(tp_char);
1351
1352         return true;
1353 }
1354
1355 /*
1356  * Return the specified line position in the old file of the old context.
1357  */
1358 LINENUM
1359 pch_first(void)
1360 {
1361         return p_first;
1362 }
1363
1364 /*
1365  * Return the number of lines of old context.
1366  */
1367 LINENUM
1368 pch_ptrn_lines(void)
1369 {
1370         return p_ptrn_lines;
1371 }
1372
1373 /*
1374  * Return the probable line position in the new file of the first line.
1375  */
1376 LINENUM
1377 pch_newfirst(void)
1378 {
1379         return p_newfirst;
1380 }
1381
1382 /*
1383  * Return the number of lines in the replacement text including context.
1384  */
1385 LINENUM
1386 pch_repl_lines(void)
1387 {
1388         return p_repl_lines;
1389 }
1390
1391 /*
1392  * Return the number of lines in the whole hunk.
1393  */
1394 LINENUM
1395 pch_end(void)
1396 {
1397         return p_end;
1398 }
1399
1400 /*
1401  * Return the number of context lines before the first changed line.
1402  */
1403 LINENUM
1404 pch_context(void)
1405 {
1406         return p_context;
1407 }
1408
1409 /*
1410  * Return the length of a particular patch line.
1411  */
1412 unsigned short
1413 pch_line_len(LINENUM line)
1414 {
1415         return p_len[line];
1416 }
1417
1418 /*
1419  * Return the control character (+, -, *, !, etc) for a patch line.
1420  */
1421 char
1422 pch_char(LINENUM line)
1423 {
1424         return p_char[line];
1425 }
1426
1427 /*
1428  * Return a pointer to a particular patch line.
1429  */
1430 char *
1431 pfetch(LINENUM line)
1432 {
1433         return p_line[line];
1434 }
1435
1436 /*
1437  * Return where in the patch file this hunk began, for error messages.
1438  */
1439 LINENUM
1440 pch_hunk_beg(void)
1441 {
1442         return p_hunk_beg;
1443 }
1444
1445 /*
1446  * Apply an ed script by feeding ed itself.
1447  */
1448 void
1449 do_ed_script(void)
1450 {
1451         char    *t;
1452         off_t   beginning_of_this_line;
1453         FILE    *pipefp = NULL;
1454         int     continuation;
1455
1456         if (!skip_rest_of_patch) {
1457                 if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1458                         unlink(TMPOUTNAME);
1459                         fatal("can't create temp file %s", TMPOUTNAME);
1460                 }
1461                 snprintf(buf, buf_size, "%s%s%s", _PATH_RED,
1462                     verbose ? " " : " -s ", TMPOUTNAME);
1463                 pipefp = popen(buf, "w");
1464         }
1465         for (;;) {
1466                 beginning_of_this_line = ftello(pfp);
1467                 if (pgets(true) == 0) {
1468                         next_intuit_at(beginning_of_this_line, p_input_line);
1469                         break;
1470                 }
1471                 p_input_line++;
1472                 for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1473                         ;
1474                 /* POSIX defines allowed commands as {a,c,d,i,s} */
1475                 if (isdigit((unsigned char)*buf) &&
1476                     (*t == 'a' || *t == 'c' || *t == 'd' || *t == 'i' || *t == 's')) {
1477                         if (pipefp != NULL)
1478                                 fputs(buf, pipefp);
1479                         if (*t == 's') {
1480                                 for (;;) {
1481                                         continuation = 0;
1482                                         t = strchr(buf, '\0') - 1;
1483                                         while (--t >= buf && *t == '\\')
1484                                                 continuation = !continuation;
1485                                         if (!continuation ||
1486                                             pgets(true) == 0)
1487                                                 break;
1488                                         if (pipefp != NULL)
1489                                                 fputs(buf, pipefp);
1490                                 }
1491                         } else if (*t != 'd') {
1492                                 while (pgets(true)) {
1493                                         p_input_line++;
1494                                         if (pipefp != NULL)
1495                                                 fputs(buf, pipefp);
1496                                         if (strEQ(buf, ".\n"))
1497                                                 break;
1498                                 }
1499                         }
1500                 } else {
1501                         next_intuit_at(beginning_of_this_line, p_input_line);
1502                         break;
1503                 }
1504         }
1505         if (pipefp == NULL)
1506                 return;
1507         fprintf(pipefp, "w\n");
1508         fprintf(pipefp, "q\n");
1509         fflush(pipefp);
1510         pclose(pipefp);
1511         ignore_signals();
1512         if (!check_only) {
1513                 if (move_file(TMPOUTNAME, outname) < 0) {
1514                         toutkeep = true;
1515                         chmod(TMPOUTNAME, filemode);
1516                 } else
1517                         chmod(outname, filemode);
1518         }
1519         set_signals(1);
1520 }
1521
1522 /*
1523  * Choose the name of the file to be patched based on POSIX rules.
1524  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1525  *       if the user specified --posix or set POSIXLY_CORRECT.
1526  */
1527 static char *
1528 posix_name(const struct file_name *names, bool assume_exists)
1529 {
1530         char *path = NULL;
1531         int i;
1532
1533         /*
1534          * POSIX states that the filename will be chosen from one
1535          * of the old, new and index names (in that order) if
1536          * the file exists relative to CWD after -p stripping.
1537          */
1538         for (i = 0; i < MAX_FILE; i++) {
1539                 if (names[i].path != NULL && names[i].exists) {
1540                         path = names[i].path;
1541                         break;
1542                 }
1543         }
1544         if (path == NULL && !assume_exists) {
1545                 /*
1546                  * No files found, check to see if the diff could be
1547                  * creating a new file.
1548                  */
1549                 if (path == NULL && ok_to_create_file &&
1550                     names[NEW_FILE].path != NULL)
1551                         path = names[NEW_FILE].path;
1552         }
1553
1554         return path ? xstrdup(path) : NULL;
1555 }
1556
1557 static char *
1558 compare_names(const struct file_name *names, bool assume_exists)
1559 {
1560         size_t min_components, min_baselen, min_len, tmp;
1561         char *best = NULL;
1562         char *path;
1563         int i;
1564
1565         /*
1566          * The "best" name is the one with the fewest number of path
1567          * components, the shortest basename length, and the shortest
1568          * overall length (in that order).  We only use the Index: file
1569          * if neither of the old or new files could be intuited from
1570          * the diff header.
1571          */
1572         min_components = min_baselen = min_len = SIZE_MAX;
1573         for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1574                 path = names[i].path;
1575                 if (path == NULL || (!names[i].exists && !assume_exists))
1576                         continue;
1577                 if ((tmp = num_components(path)) > min_components)
1578                         continue;
1579                 if (tmp < min_components) {
1580                         min_components = tmp;
1581                         best = path;
1582                 }
1583                 if ((tmp = strlen(basename(path))) > min_baselen)
1584                         continue;
1585                 if (tmp < min_baselen) {
1586                         min_baselen = tmp;
1587                         best = path;
1588                 }
1589                 if ((tmp = strlen(path)) > min_len)
1590                         continue;
1591                 min_len = tmp;
1592                 best = path;
1593         }
1594         return best;
1595 }
1596
1597 /*
1598  * Choose the name of the file to be patched based the "best" one
1599  * available.
1600  */
1601 static char *
1602 best_name(const struct file_name *names, bool assume_exists)
1603 {
1604         char *best;
1605
1606         best = compare_names(names, assume_exists);
1607
1608         /* No match?  Check to see if the diff could be creating a new file. */
1609         if (best == NULL && ok_to_create_file)
1610                 best = names[NEW_FILE].path;
1611
1612         return best ? xstrdup(best) : NULL;
1613 }
1614
1615 static size_t
1616 num_components(const char *path)
1617 {
1618         size_t n;
1619         const char *cp;
1620
1621         for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1622                 while (*cp == '/')
1623                         cp++;           /* skip consecutive slashes */
1624         }
1625         return n;
1626 }
1627
1628 /*
1629  * Convert number at NPTR into LINENUM and save address of first
1630  * character that is not a digit in ENDPTR.  If conversion is not
1631  * possible, call fatal.
1632  */
1633 static LINENUM
1634 strtolinenum(char *nptr, char **endptr)
1635 {
1636         LINENUM rv;
1637         char c;
1638         char *p;
1639         const char *errstr;
1640
1641         for (p = nptr; isdigit((unsigned char)*p); p++)
1642                 ;
1643
1644         if (p == nptr)
1645                 malformed();
1646
1647         c = *p;
1648         *p = '\0';
1649
1650         rv = strtonum(nptr, 0, LINENUM_MAX, &errstr);
1651         if (errstr != NULL)
1652                 fatal("invalid line number at line %ld: `%s' is %s\n",
1653                     p_input_line, nptr, errstr);
1654
1655         *p = c;
1656         *endptr = p;
1657
1658         return rv;
1659 }