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 (p_max - p_end < 4) {
 591                                         /* assume blank lines got chopped */
 592                                         strlcpy(buf, "  \n", buf_size);
 593                                 } else {
 594                                         if (repl_beginning && repl_could_be_missing) {
 595                                                 repl_missing = true;
 596                                                 goto hunk_done;
 597                                         }
 598                                         fatal("unexpected end of file in patch\n");
 599                                 }
 600                         }
 601                         p_end++;
 602                         if (p_end >= hunkmax)
 603                                 fatal("Internal error: hunk larger than hunk "
 604                                     "buffer size");
 605                         p_char[p_end] = *buf;
 606                         p_line[p_end] = NULL;
 607                         switch (*buf) {
 608                         case '*':
 609                                 if (strnEQ(buf, "********", 8)) {
 610                                         if (repl_beginning && repl_could_be_missing) {
 611                                                 repl_missing = true;
 612                                                 goto hunk_done;
 613                                         } else
 614                                                 fatal("unexpected end of hunk "
 615                                                     "at line %ld\n",
 616                                                     p_input_line);
 617                                 }
 618                                 if (p_end != 0) {
 619                                         if (repl_beginning && repl_could_be_missing) {
 620                                                 repl_missing = true;
 621                                                 goto hunk_done;
 622                                         }
 623                                         fatal("unexpected *** at line %ld: %s",
 624                                             p_input_line, buf);
 625                                 }
 626                                 context = 0;
 627                                 p_line[p_end] = savestr(buf);
 628                                 if (out_of_mem) {
 629                                         p_end--;
 630                                         return false;
 631                                 }
 632                                 for (s = buf;
 633                                      *s && !isdigit((unsigned char)*s); s++)
 634                                         ;
 635                                 if (!*s)
 636                                         malformed();
 637                                 if (strnEQ(s, "0,0", 3))
 638                                         memmove(s, s + 2, strlen(s + 2) + 1);
 639                                 p_first = strtolinenum(s, &s);
 640                                 if (*s == ',') {
 641                                         for (;
 642                                              *s && !isdigit((unsigned char)*s); s++)
 643                                                 ;
 644                                         if (!*s)
 645                                                 malformed();
 646                                         p_ptrn_lines = strtolinenum(s, &s) - p_first + 1;
 647                                         if (p_ptrn_lines < 0)
 648                                                 malformed();
 649                                 } else if (p_first)
 650                                         p_ptrn_lines = 1;
 651                                 else {
 652                                         p_ptrn_lines = 0;
 653                                         p_first = 1;
 654                                 }
 655                                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 656                                     p_ptrn_lines >= LINENUM_MAX - 6)
 657                                         malformed();
 658
 659                                 /* we need this much at least */
 660                                 p_max = p_ptrn_lines + 6;
 661                                 while (p_max >= hunkmax)
 662                                         grow_hunkmax();
 663                                 p_max = hunkmax;
 664                                 break;
 665                         case '-':
 666                                 if (buf[1] == '-') {
 667                                         if (repl_beginning ||
 668                                             (p_end != p_ptrn_lines + 1 +
 669                                             (p_char[p_end - 1] == '\n'))) {
 670                                                 if (p_end == 1) {
 671                                                         /*
 672                                                          * `old' lines were omitted;
 673                                                          * set up to fill them in
 674                                                          * from 'new' context lines.
 675                                                          */
 676                                                         p_end = p_ptrn_lines + 1;
 677                                                         fillsrc = p_end + 1;
 678                                                         filldst = 1;
 679                                                         fillcnt = p_ptrn_lines;
 680                                                 } else {
 681                                                         if (repl_beginning) {
 682                                                                 if (repl_could_be_missing) {
 683                                                                         repl_missing = true;
 684                                                                         goto hunk_done;
 685                                                                 }
 686                                                                 fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
 687                                                                     p_input_line, p_hunk_beg + repl_beginning);
 688                                                         } else {
 689                                                                 fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
 690                                                                     (p_end <= p_ptrn_lines
 691                                                                     ? "Premature"
 692                                                                     : "Overdue"),
 693                                                                     p_input_line, p_hunk_beg);
 694                                                         }
 695                                                 }
 696                                         }
 697                                         repl_beginning = p_end;
 698                                         repl_backtrack_position = ftello(pfp);
 699                                         repl_patch_line = p_input_line;
 700                                         p_line[p_end] = savestr(buf);
 701                                         if (out_of_mem) {
 702                                                 p_end--;
 703                                                 return false;
 704                                         }
 705                                         p_char[p_end] = '=';
 706                                         for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 707                                                 ;
 708                                         if (!*s)
 709                                                 malformed();
 710                                         p_newfirst = strtolinenum(s, &s);
 711                                         if (*s == ',') {
 712                                                 for (; *s && !isdigit((unsigned char)*s); s++)
 713                                                         ;
 714                                                 if (!*s)
 715                                                         malformed();
 716                                                 p_repl_lines = strtolinenum(s, &s) -
 717                                                     p_newfirst + 1;
 718                                                 if (p_repl_lines < 0)
 719                                                         malformed();
 720                                         } else if (p_newfirst)
 721                                                 p_repl_lines = 1;
 722                                         else {
 723                                                 p_repl_lines = 0;
 724                                                 p_newfirst = 1;
 725                                         }
 726                                         if (p_newfirst >= LINENUM_MAX - p_repl_lines ||
 727                                             p_repl_lines >= LINENUM_MAX - p_end)
 728                                                 malformed();
 729                                         p_max = p_repl_lines + p_end;
 730                                         if (p_max > MAXHUNKSIZE)
 731                                                 fatal("hunk too large (%ld lines) at line %ld: %s",
 732                                                     p_max, p_input_line, buf);
 733                                         while (p_max >= hunkmax)
 734                                                 grow_hunkmax();
 735                                         if (p_repl_lines != ptrn_copiable &&
 736                                             (p_context != 0 || p_repl_lines != 1))
 737                                                 repl_could_be_missing = false;
 738                                         break;
 739                                 }
 740                                 goto change_line;
 741                         case '+':
 742                         case '!':
 743                                 repl_could_be_missing = false;
 744                 change_line:
 745                                 if (buf[1] == '\n' && canonicalize)
 746                                         strlcpy(buf + 1, " \n", buf_size - 1);
 747                                 if (!isspace((unsigned char)buf[1]) &&
 748                                     buf[1] != '>' && buf[1] != '<' &&
 749                                     repl_beginning && repl_could_be_missing) {
 750                                         repl_missing = true;
 751                                         goto hunk_done;
 752                                 }
 753                                 if (context >= 0) {
 754                                         if (context < p_context)
 755                                                 p_context = context;
 756                                         context = -1000;
 757                                 }
 758                                 p_line[p_end] = savestr(buf + 2);
 759                                 if (out_of_mem) {
 760                                         p_end--;
 761                                         return false;
 762                                 }
 763                                 if (p_end == p_ptrn_lines) {
 764                                         if (remove_special_line()) {
 765                                                 int     l;
 766
 767                                                 l = strlen(p_line[p_end]) - 1;
 768                                                 (p_line[p_end])[l] = 0;
 769                                         }
 770                                 }
 771                                 break;
 772                         case '\t':
 773                         case '\n':      /* assume the 2 spaces got eaten */
 774                                 if (repl_beginning && repl_could_be_missing &&
 775                                     (!ptrn_spaces_eaten ||
 776                                     diff_type == NEW_CONTEXT_DIFF)) {
 777                                         repl_missing = true;
 778                                         goto hunk_done;
 779                                 }
 780                                 p_line[p_end] = savestr(buf);
 781                                 if (out_of_mem) {
 782                                         p_end--;
 783                                         return false;
 784                                 }
 785                                 if (p_end != p_ptrn_lines + 1) {
 786                                         ptrn_spaces_eaten |= (repl_beginning != 0);
 787                                         context++;
 788                                         if (!repl_beginning)
 789                                                 ptrn_copiable++;
 790                                         p_char[p_end] = ' ';
 791                                 }
 792                                 break;
 793                         case ' ':
 794                                 if (!isspace((unsigned char)buf[1]) &&
 795                                     repl_beginning && repl_could_be_missing) {
 796                                         repl_missing = true;
 797                                         goto hunk_done;
 798                                 }
 799                                 context++;
 800                                 if (!repl_beginning)
 801                                         ptrn_copiable++;
 802                                 p_line[p_end] = savestr(buf + 2);
 803                                 if (out_of_mem) {
 804                                         p_end--;
 805                                         return false;
 806                                 }
 807                                 break;
 808                         default:
 809                                 if (repl_beginning && repl_could_be_missing) {
 810                                         repl_missing = true;
 811                                         goto hunk_done;
 812                                 }
 813                                 malformed();
 814                         }
 815                         /* set up p_len for strncmp() so we don't have to */
 816                         /* assume null termination */
 817                         if (p_line[p_end])
 818                                 p_len[p_end] = strlen(p_line[p_end]);
 819                         else
 820                                 p_len[p_end] = 0;
 821                 }
 822
 823 hunk_done:
 824                 if (p_end >= 0 && !repl_beginning)
 825                         fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
 826
 827                 if (repl_missing) {
 828
 829                         /* reset state back to just after --- */
 830                         p_input_line = repl_patch_line;
 831                         for (p_end--; p_end > repl_beginning; p_end--)
 832                                 free(p_line[p_end]);
 833                         fseeko(pfp, repl_backtrack_position, SEEK_SET);
 834
 835                         /* redundant 'new' context lines were omitted - set */
 836                         /* up to fill them in from the old file context */
 837                         if (!p_context && p_repl_lines == 1) {
 838                                 p_repl_lines = 0;
 839                                 p_max--;
 840                         }
 841                         fillsrc = 1;
 842                         filldst = repl_beginning + 1;
 843                         fillcnt = p_repl_lines;
 844                         p_end = p_max;
 845                 } else if (!p_context && fillcnt == 1) {
 846                         /* the first hunk was a null hunk with no context */
 847                         /* and we were expecting one line -- fix it up. */
 848                         while (filldst < p_end) {
 849                                 p_line[filldst] = p_line[filldst + 1];
 850                                 p_char[filldst] = p_char[filldst + 1];
 851                                 p_len[filldst] = p_len[filldst + 1];
 852                                 filldst++;
 853                         }
 854 #if 0
 855                         repl_beginning--;       /* this doesn't need to be fixed */
 856 #endif
 857                         p_end--;
 858                         p_first++;      /* do append rather than insert */
 859                         fillcnt = 0;
 860                         p_ptrn_lines = 0;
 861                 }
 862                 if (diff_type == CONTEXT_DIFF &&
 863                     (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
 864                         if (verbose)
 865                                 say("%s\n%s\n%s\n",
 866                                     "(Fascinating--this is really a new-style context diff but without",
 867                                     "the telltale extra asterisks on the *** line that usually indicate",
 868                                     "the new style...)");
 869                         diff_type = NEW_CONTEXT_DIFF;
 870                 }
 871                 /* if there were omitted context lines, fill them in now */
 872                 if (fillcnt) {
 873                         p_bfake = filldst;      /* remember where not to free() */
 874                         p_efake = filldst + fillcnt - 1;
 875                         while (fillcnt-- > 0) {
 876                                 while (fillsrc <= p_end && p_char[fillsrc] != ' ')
 877                                         fillsrc++;
 878                                 if (fillsrc > p_end)
 879                                         fatal("replacement text or line numbers mangled in hunk at line %ld\n",
 880                                             p_hunk_beg);
 881                                 p_line[filldst] = p_line[fillsrc];
 882                                 p_char[filldst] = p_char[fillsrc];
 883                                 p_len[filldst] = p_len[fillsrc];
 884                                 fillsrc++;
 885                                 filldst++;
 886                         }
 887                         while (fillsrc <= p_end && fillsrc != repl_beginning &&
 888                             p_char[fillsrc] != ' ')
 889                                 fillsrc++;
 890 #ifdef DEBUGGING
 891                         if (debug & 64)
 892                                 printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
 893                                 fillsrc, filldst, repl_beginning, p_end + 1);
 894 #endif
 895                         if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
 896                                 malformed();
 897                         if (filldst != p_end + 1 && filldst != repl_beginning)
 898                                 malformed();
 899                 }
 900                 if (p_line[p_end] != NULL) {
 901                         if (remove_special_line()) {
 902                                 p_len[p_end] -= 1;
 903                                 (p_line[p_end])[p_len[p_end]] = 0;
 904                         }
 905                 }
 906         } else if (diff_type == UNI_DIFF) {
 907                 LINENUM fillold;        /* index of old lines */
 908                 LINENUM fillnew;        /* index of new lines */
 909                 char    ch;
 910
 911                 line_beginning = ftello(pfp); /* file pos of the current line */
 912                 len = pgets(true);
 913                 p_input_line++;
 914                 if (len == 0 || strnNE(buf, "@@ -", 4)) {
 915                         next_intuit_at(line_beginning, p_input_line);
 916                         return false;
 917                 }
 918                 s = buf + 4;
 919                 if (!*s)
 920                         malformed();
 921                 p_first = strtolinenum(s, &s);
 922                 if (*s == ',') {
 923                         p_ptrn_lines = strtolinenum(s + 1, &s);
 924                 } else
 925                         p_ptrn_lines = 1;
 926                 if (*s == ' ')
 927                         s++;
 928                 if (*s != '+' || !*++s)
 929                         malformed();
 930                 p_newfirst = strtolinenum(s, &s);
 931                 if (*s == ',') {
 932                         p_repl_lines = strtolinenum(s + 1, &s);
 933                 } else
 934                         p_repl_lines = 1;
 935                 if (*s == ' ')
 936                         s++;
 937                 if (*s != '@')
 938                         malformed();
 939                 if (p_first >= LINENUM_MAX - p_ptrn_lines ||
 940                     p_newfirst > LINENUM_MAX - p_repl_lines ||
 941                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
 942                         malformed();
 943                 if (!p_ptrn_lines)
 944                         p_first++;      /* do append rather than insert */
 945                 p_max = p_ptrn_lines + p_repl_lines + 1;
 946                 while (p_max >= hunkmax)
 947                         grow_hunkmax();
 948                 fillold = 1;
 949                 fillnew = fillold + p_ptrn_lines;
 950                 p_end = fillnew + p_repl_lines;
 951                 snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
 952                     p_first + p_ptrn_lines - 1);
 953                 p_line[0] = savestr(buf);
 954                 if (out_of_mem) {
 955                         p_end = -1;
 956                         return false;
 957                 }
 958                 p_char[0] = '*';
 959                 snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
 960                     p_newfirst + p_repl_lines - 1);
 961                 p_line[fillnew] = savestr(buf);
 962                 if (out_of_mem) {
 963                         p_end = 0;
 964                         return false;
 965                 }
 966                 p_char[fillnew++] = '=';
 967                 p_context = 100;
 968                 context = 0;
 969                 p_hunk_beg = p_input_line + 1;
 970                 while (fillold <= p_ptrn_lines || fillnew <= p_end) {
 971                         line_beginning = ftello(pfp);
 972                         len = pgets(true);
 973                         p_input_line++;
 974                         if (len == 0) {
 975                                 if (p_max - fillnew < 3) {
 976                                         /* assume blank lines got chopped */
 977                                         strlcpy(buf, " \n", buf_size);
 978                                 } else {
 979                                         fatal("unexpected end of file in patch\n");
 980                                 }
 981                         }
 982                         if (*buf == '\t' || *buf == '\n') {
 983                                 ch = ' ';       /* assume the space got eaten */
 984                                 s = savestr(buf);
 985                         } else {
 986                                 ch = *buf;
 987                                 s = savestr(buf + 1);
 988                         }
 989                         if (out_of_mem) {
 990                                 while (--fillnew > p_ptrn_lines)
 991                                         free(p_line[fillnew]);
 992                                 p_end = fillold - 1;
 993                                 return false;
 994                         }
 995                         switch (ch) {
 996                         case '-':
 997                                 if (fillold > p_ptrn_lines) {
 998                                         free(s);
 999                                         p_end = fillnew - 1;
1000                                         malformed();
1001                                 }
1002                                 p_char[fillold] = ch;
1003                                 p_line[fillold] = s;
1004                                 p_len[fillold++] = strlen(s);
1005                                 if (fillold > p_ptrn_lines) {
1006                                         if (remove_special_line()) {
1007                                                 p_len[fillold - 1] -= 1;
1008                                                 s[p_len[fillold - 1]] = 0;
1009                                         }
1010                                 }
1011                                 break;
1012                         case '=':
1013                                 ch = ' ';
1014                                 /* FALL THROUGH */
1015                         case ' ':
1016                                 if (fillold > p_ptrn_lines) {
1017                                         free(s);
1018                                         while (--fillnew > p_ptrn_lines)
1019                                                 free(p_line[fillnew]);
1020                                         p_end = fillold - 1;
1021                                         malformed();
1022                                 }
1023                                 context++;
1024                                 p_char[fillold] = ch;
1025                                 p_line[fillold] = s;
1026                                 p_len[fillold++] = strlen(s);
1027                                 s = savestr(s);
1028                                 if (out_of_mem) {
1029                                         while (--fillnew > p_ptrn_lines)
1030                                                 free(p_line[fillnew]);
1031                                         p_end = fillold - 1;
1032                                         return false;
1033                                 }
1034                                 if (fillold > p_ptrn_lines) {
1035                                         if (remove_special_line()) {
1036                                                 p_len[fillold - 1] -= 1;
1037                                                 s[p_len[fillold - 1]] = 0;
1038                                         }
1039                                 }
1040                                 /* FALL THROUGH */
1041                         case '+':
1042                                 if (fillnew > p_end) {
1043                                         free(s);
1044                                         while (--fillnew > p_ptrn_lines)
1045                                                 free(p_line[fillnew]);
1046                                         p_end = fillold - 1;
1047                                         malformed();
1048                                 }
1049                                 p_char[fillnew] = ch;
1050                                 p_line[fillnew] = s;
1051                                 p_len[fillnew++] = strlen(s);
1052                                 if (fillold > p_ptrn_lines) {
1053                                         if (remove_special_line()) {
1054                                                 p_len[fillnew - 1] -= 1;
1055                                                 s[p_len[fillnew - 1]] = 0;
1056                                         }
1057                                 }
1058                                 break;
1059                         default:
1060                                 p_end = fillnew;
1061                                 malformed();
1062                         }
1063                         if (ch != ' ' && context > 0) {
1064                                 if (context < p_context)
1065                                         p_context = context;
1066                                 context = -1000;
1067                         }
1068                 }               /* while */
1069         } else {                /* normal diff--fake it up */
1070                 char    hunk_type;
1071                 int     i;
1072                 LINENUM min, max;
1073
1074                 line_beginning = ftello(pfp);
1075                 p_context = 0;
1076                 len = pgets(true);
1077                 p_input_line++;
1078                 if (len == 0 || !isdigit((unsigned char)*buf)) {
1079                         next_intuit_at(line_beginning, p_input_line);
1080                         return false;
1081                 }
1082                 p_first = strtolinenum(buf, &s);
1083                 if (*s == ',') {
1084                         p_ptrn_lines = strtolinenum(s + 1, &s) - p_first + 1;
1085                         if (p_ptrn_lines < 0)
1086                                 malformed();
1087                 } else
1088                         p_ptrn_lines = (*s != 'a');
1089                 hunk_type = *s;
1090                 if (hunk_type == 'a')
1091                         p_first++;      /* do append rather than insert */
1092                 min = strtolinenum(s + 1, &s);
1093                 if (*s == ',')
1094                         max = strtolinenum(s + 1, &s);
1095                 else
1096                         max = min;
1097                 if (min < 0 || min > max || max - min == LINENUM_MAX)
1098                         malformed();
1099                 if (hunk_type == 'd')
1100                         min++;
1101                 p_newfirst = min;
1102                 p_repl_lines = max - min + 1;
1103                 if (p_newfirst > LINENUM_MAX - p_repl_lines ||
1104                     p_ptrn_lines >= LINENUM_MAX - p_repl_lines - 1)
1105                         malformed();
1106                 p_end = p_ptrn_lines + p_repl_lines + 1;
1107                 if (p_end > MAXHUNKSIZE)
1108                         fatal("hunk too large (%ld lines) at line %ld: %s",
1109                             p_end, p_input_line, buf);
1110                 while (p_end >= hunkmax)
1111                         grow_hunkmax();
1112                 snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1113                     p_first + p_ptrn_lines - 1);
1114                 p_line[0] = savestr(buf);
1115                 if (out_of_mem) {
1116                         p_end = -1;
1117                         return false;
1118                 }
1119                 p_char[0] = '*';
1120                 for (i = 1; i <= p_ptrn_lines; i++) {
1121                         len = pgets(true);
1122                         p_input_line++;
1123                         if (len == 0)
1124                                 fatal("unexpected end of file in patch at line %ld\n",
1125                                     p_input_line);
1126                         if (*buf != '<')
1127                                 fatal("< expected at line %ld of patch\n",
1128                                     p_input_line);
1129                         p_line[i] = savestr(buf + 2);
1130                         if (out_of_mem) {
1131                                 p_end = i - 1;
1132                                 return false;
1133                         }
1134                         p_len[i] = strlen(p_line[i]);
1135                         p_char[i] = '-';
1136                 }
1137
1138                 if (remove_special_line()) {
1139                         p_len[i - 1] -= 1;
1140                         (p_line[i - 1])[p_len[i - 1]] = 0;
1141                 }
1142                 if (hunk_type == 'c') {
1143                         len = pgets(true);
1144                         p_input_line++;
1145                         if (len == 0)
1146                                 fatal("unexpected end of file in patch at line %ld\n",
1147                                     p_input_line);
1148                         if (*buf != '-')
1149                                 fatal("--- expected at line %ld of patch\n",
1150                                     p_input_line);
1151                 }
1152                 snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1153                 p_line[i] = savestr(buf);
1154                 if (out_of_mem) {
1155                         p_end = i - 1;
1156                         return false;
1157                 }
1158                 p_char[i] = '=';
1159                 for (i++; i <= p_end; i++) {
1160                         len = pgets(true);
1161                         p_input_line++;
1162                         if (len == 0)
1163                                 fatal("unexpected end of file in patch at line %ld\n",
1164                                     p_input_line);
1165                         if (*buf != '>')
1166                                 fatal("> expected at line %ld of patch\n",
1167                                     p_input_line);
1168                         /* Don't overrun if we don't have enough line */
1169                         if (len > 2)
1170                                 p_line[i] = savestr(buf + 2);
1171                         else
1172                                 p_line[i] = savestr("");
1173
1174                         if (out_of_mem) {
1175                                 p_end = i - 1;
1176                                 return false;
1177                         }
1178                         p_len[i] = strlen(p_line[i]);
1179                         p_char[i] = '+';
1180                 }
1181
1182                 if (remove_special_line()) {
1183                         p_len[i - 1] -= 1;
1184                         (p_line[i - 1])[p_len[i - 1]] = 0;
1185                 }
1186         }
1187         if (reverse)            /* backwards patch? */
1188                 if (!pch_swap())
1189                         say("Not enough memory to swap next hunk!\n");
1190 #ifdef DEBUGGING
1191         if (debug & 2) {
1192                 LINENUM i;
1193                 char    special;
1194
1195                 for (i = 0; i <= p_end; i++) {
1196                         if (i == p_ptrn_lines)
1197                                 special = '^';
1198                         else
1199                                 special = ' ';
1200                         fprintf(stderr, "%3ld %c %c %s", i, p_char[i],
1201                             special, p_line[i]);
1202                         fflush(stderr);
1203                 }
1204         }
1205 #endif
1206         if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1207                 p_char[p_end + 1] = '^';        /* add a stopper for apply_hunk */
1208         return true;
1209 }
1210
1211 /*
1212  * Input a line from the patch file.
1213  * Worry about indentation if do_indent is true.
1214  * The line is read directly into the buf global variable which
1215  * is resized if necessary in order to hold the complete line.
1216  * Returns the number of characters read including the terminating
1217  * '\n', if any.
1218  */
1219 size_t
1220 pgets(bool do_indent)
1221 {
1222         char *line;
1223         size_t len;
1224         int indent = 0, skipped = 0;
1225
1226         line = fgetln(pfp, &len);
1227         if (line != NULL) {
1228                 if (len + 1 > buf_size) {
1229                         while (len + 1 > buf_size)
1230                                 buf_size *= 2;
1231                         free(buf);
1232                         buf = malloc(buf_size);
1233                         if (buf == NULL)
1234                                 fatal("out of memory\n");
1235                 }
1236                 if (do_indent == 1 && p_indent) {
1237                         for (;
1238                             indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1239                             line++, skipped++) {
1240                                 if (*line == '\t')
1241                                         indent += 8 - (indent %7);
1242                                 else
1243                                         indent++;
1244                         }
1245                 }
1246                 memcpy(buf, line, len - skipped);
1247                 buf[len - skipped] = '\0';
1248         }
1249         return len;
1250 }
1251
1252
1253 /*
1254  * Reverse the old and new portions of the current hunk.
1255  */
1256 bool
1257 pch_swap(void)
1258 {
1259         char    **tp_line;      /* the text of the hunk */
1260         unsigned short  *tp_len;/* length of each line */
1261         char    *tp_char;       /* +, -, and ! */
1262         LINENUM i;
1263         LINENUM n;
1264         bool    blankline = false;
1265         char    *s;
1266
1267         i = p_first;
1268         p_first = p_newfirst;
1269         p_newfirst = i;
1270
1271         /* make a scratch copy */
1272
1273         tp_line = p_line;
1274         tp_len = p_len;
1275         tp_char = p_char;
1276         p_line = NULL;  /* force set_hunkmax to allocate again */
1277         p_len = NULL;
1278         p_char = NULL;
1279         set_hunkmax();
1280         if (p_line == NULL || p_len == NULL || p_char == NULL) {
1281
1282                 free(p_line);
1283                 p_line = tp_line;
1284                 free(p_len);
1285                 p_len = tp_len;
1286                 free(p_char);
1287                 p_char = tp_char;
1288                 return false;   /* not enough memory to swap hunk! */
1289         }
1290         /* now turn the new into the old */
1291
1292         i = p_ptrn_lines + 1;
1293         if (tp_char[i] == '\n') {       /* account for possible blank line */
1294                 blankline = true;
1295                 i++;
1296         }
1297         if (p_efake >= 0) {     /* fix non-freeable ptr range */
1298                 if (p_efake <= i)
1299                         n = p_end - i + 1;
1300                 else
1301                         n = -i;
1302                 p_efake += n;
1303                 p_bfake += n;
1304         }
1305         for (n = 0; i <= p_end; i++, n++) {
1306                 p_line[n] = tp_line[i];
1307                 p_char[n] = tp_char[i];
1308                 if (p_char[n] == '+')
1309                         p_char[n] = '-';
1310                 p_len[n] = tp_len[i];
1311         }
1312         if (blankline) {
1313                 i = p_ptrn_lines + 1;
1314                 p_line[n] = tp_line[i];
1315                 p_char[n] = tp_char[i];
1316                 p_len[n] = tp_len[i];
1317                 n++;
1318         }
1319         if (p_char[0] != '=')
1320                 fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1321                     p_input_line, p_char[0]);
1322         p_char[0] = '*';
1323         for (s = p_line[0]; *s; s++)
1324                 if (*s == '-')
1325                         *s = '*';
1326
1327         /* now turn the old into the new */
1328
1329         if (p_char[0] != '*')
1330                 fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1331                     p_input_line, p_char[0]);
1332         tp_char[0] = '=';
1333         for (s = tp_line[0]; *s; s++)
1334                 if (*s == '*')
1335                         *s = '-';
1336         for (i = 0; n <= p_end; i++, n++) {
1337                 p_line[n] = tp_line[i];
1338                 p_char[n] = tp_char[i];
1339                 if (p_char[n] == '-')
1340                         p_char[n] = '+';
1341                 p_len[n] = tp_len[i];
1342         }
1343
1344         if (i != p_ptrn_lines + 1)
1345                 fatal("Malformed patch at line %ld: expected %ld lines, "
1346                     "got %ld\n",
1347                     p_input_line, p_ptrn_lines + 1, i);
1348
1349         i = p_ptrn_lines;
1350         p_ptrn_lines = p_repl_lines;
1351         p_repl_lines = i;
1352
1353         free(tp_line);
1354         free(tp_len);
1355         free(tp_char);
1356
1357         return true;
1358 }
1359
1360 /*
1361  * Return the specified line position in the old file of the old context.
1362  */
1363 LINENUM
1364 pch_first(void)
1365 {
1366         return p_first;
1367 }
1368
1369 /*
1370  * Return the number of lines of old context.
1371  */
1372 LINENUM
1373 pch_ptrn_lines(void)
1374 {
1375         return p_ptrn_lines;
1376 }
1377
1378 /*
1379  * Return the probable line position in the new file of the first line.
1380  */
1381 LINENUM
1382 pch_newfirst(void)
1383 {
1384         return p_newfirst;
1385 }
1386
1387 /*
1388  * Return the number of lines in the replacement text including context.
1389  */
1390 LINENUM
1391 pch_repl_lines(void)
1392 {
1393         return p_repl_lines;
1394 }
1395
1396 /*
1397  * Return the number of lines in the whole hunk.
1398  */
1399 LINENUM
1400 pch_end(void)
1401 {
1402         return p_end;
1403 }
1404
1405 /*
1406  * Return the number of context lines before the first changed line.
1407  */
1408 LINENUM
1409 pch_context(void)
1410 {
1411         return p_context;
1412 }
1413
1414 /*
1415  * Return the length of a particular patch line.
1416  */
1417 unsigned short
1418 pch_line_len(LINENUM line)
1419 {
1420         return p_len[line];
1421 }
1422
1423 /*
1424  * Return the control character (+, -, *, !, etc) for a patch line.
1425  */
1426 char
1427 pch_char(LINENUM line)
1428 {
1429         return p_char[line];
1430 }
1431
1432 /*
1433  * Return a pointer to a particular patch line.
1434  */
1435 char *
1436 pfetch(LINENUM line)
1437 {
1438         return p_line[line];
1439 }
1440
1441 /*
1442  * Return where in the patch file this hunk began, for error messages.
1443  */
1444 LINENUM
1445 pch_hunk_beg(void)
1446 {
1447         return p_hunk_beg;
1448 }
1449
1450 /*
1451  * Apply an ed script by feeding ed itself.
1452  */
1453 void
1454 do_ed_script(void)
1455 {
1456         char    *t;
1457         off_t   beginning_of_this_line;
1458         FILE    *pipefp = NULL;
1459         int     continuation;
1460
1461         if (!skip_rest_of_patch) {
1462                 if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1463                         unlink(TMPOUTNAME);
1464                         fatal("can't create temp file %s", TMPOUTNAME);
1465                 }
1466                 snprintf(buf, buf_size, "%s%s%s", _PATH_RED,
1467                     verbose ? " " : " -s ", TMPOUTNAME);
1468                 pipefp = popen(buf, "w");
1469         }
1470         for (;;) {
1471                 beginning_of_this_line = ftello(pfp);
1472                 if (pgets(true) == 0) {
1473                         next_intuit_at(beginning_of_this_line, p_input_line);
1474                         break;
1475                 }
1476                 p_input_line++;
1477                 for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1478                         ;
1479                 /* POSIX defines allowed commands as {a,c,d,i,s} */
1480                 if (isdigit((unsigned char)*buf) &&
1481                     (*t == 'a' || *t == 'c' || *t == 'd' || *t == 'i' || *t == 's')) {
1482                         if (pipefp != NULL)
1483                                 fputs(buf, pipefp);
1484                         if (*t == 's') {
1485                                 for (;;) {
1486                                         continuation = 0;
1487                                         t = strchr(buf, '\0') - 1;
1488                                         while (--t >= buf && *t == '\\')
1489                                                 continuation = !continuation;
1490                                         if (!continuation ||
1491                                             pgets(true) == 0)
1492                                                 break;
1493                                         if (pipefp != NULL)
1494                                                 fputs(buf, pipefp);
1495                                 }
1496                         } else if (*t != 'd') {
1497                                 while (pgets(true)) {
1498                                         p_input_line++;
1499                                         if (pipefp != NULL)
1500                                                 fputs(buf, pipefp);
1501                                         if (strEQ(buf, ".\n"))
1502                                                 break;
1503                                 }
1504                         }
1505                 } else {
1506                         next_intuit_at(beginning_of_this_line, p_input_line);
1507                         break;
1508                 }
1509         }
1510         if (pipefp == NULL)
1511                 return;
1512         fprintf(pipefp, "w\n");
1513         fprintf(pipefp, "q\n");
1514         fflush(pipefp);
1515         pclose(pipefp);
1516         ignore_signals();
1517         if (!check_only) {
1518                 if (move_file(TMPOUTNAME, outname) < 0) {
1519                         toutkeep = true;
1520                         chmod(TMPOUTNAME, filemode);
1521                 } else
1522                         chmod(outname, filemode);
1523         }
1524         set_signals(1);
1525 }
1526
1527 /*
1528  * Choose the name of the file to be patched based on POSIX rules.
1529  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1530  *       if the user specified --posix or set POSIXLY_CORRECT.
1531  */
1532 static char *
1533 posix_name(const struct file_name *names, bool assume_exists)
1534 {
1535         char *path = NULL;
1536         int i;
1537
1538         /*
1539          * POSIX states that the filename will be chosen from one
1540          * of the old, new and index names (in that order) if
1541          * the file exists relative to CWD after -p stripping.
1542          */
1543         for (i = 0; i < MAX_FILE; i++) {
1544                 if (names[i].path != NULL && names[i].exists) {
1545                         path = names[i].path;
1546                         break;
1547                 }
1548         }
1549         if (path == NULL && !assume_exists) {
1550                 /*
1551                  * No files found, check to see if the diff could be
1552                  * creating a new file.
1553                  */
1554                 if (path == NULL && ok_to_create_file &&
1555                     names[NEW_FILE].path != NULL)
1556                         path = names[NEW_FILE].path;
1557         }
1558
1559         return path ? xstrdup(path) : NULL;
1560 }
1561
1562 static char *
1563 compare_names(const struct file_name *names, bool assume_exists)
1564 {
1565         size_t min_components, min_baselen, min_len, tmp;
1566         char *best = NULL;
1567         char *path;
1568         int i;
1569
1570         /*
1571          * The "best" name is the one with the fewest number of path
1572          * components, the shortest basename length, and the shortest
1573          * overall length (in that order).  We only use the Index: file
1574          * if neither of the old or new files could be intuited from
1575          * the diff header.
1576          */
1577         min_components = min_baselen = min_len = SIZE_MAX;
1578         for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1579                 path = names[i].path;
1580                 if (path == NULL || (!names[i].exists && !assume_exists))
1581                         continue;
1582                 if ((tmp = num_components(path)) > min_components)
1583                         continue;
1584                 if (tmp < min_components) {
1585                         min_components = tmp;
1586                         best = path;
1587                 }
1588                 if ((tmp = strlen(basename(path))) > min_baselen)
1589                         continue;
1590                 if (tmp < min_baselen) {
1591                         min_baselen = tmp;
1592                         best = path;
1593                 }
1594                 if ((tmp = strlen(path)) > min_len)
1595                         continue;
1596                 min_len = tmp;
1597                 best = path;
1598         }
1599         return best;
1600 }
1601
1602 /*
1603  * Choose the name of the file to be patched based the "best" one
1604  * available.
1605  */
1606 static char *
1607 best_name(const struct file_name *names, bool assume_exists)
1608 {
1609         char *best;
1610
1611         best = compare_names(names, assume_exists);
1612
1613         /* No match?  Check to see if the diff could be creating a new file. */
1614         if (best == NULL && ok_to_create_file)
1615                 best = names[NEW_FILE].path;
1616
1617         return best ? xstrdup(best) : NULL;
1618 }
1619
1620 static size_t
1621 num_components(const char *path)
1622 {
1623         size_t n;
1624         const char *cp;
1625
1626         for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1627                 while (*cp == '/')
1628                         cp++;           /* skip consecutive slashes */
1629         }
1630         return n;
1631 }
1632
1633 /*
1634  * Convert number at NPTR into LINENUM and save address of first
1635  * character that is not a digit in ENDPTR.  If conversion is not
1636  * possible, call fatal.
1637  */
1638 static LINENUM
1639 strtolinenum(char *nptr, char **endptr)
1640 {
1641         LINENUM rv;
1642         char c;
1643         char *p;
1644         const char *errstr;
1645
1646         for (p = nptr; isdigit((unsigned char)*p); p++)
1647                 ;
1648
1649         if (p == nptr)
1650                 malformed();
1651
1652         c = *p;
1653         *p = '\0';
1654
1655         rv = strtonum(nptr, 0, LINENUM_MAX, &errstr);
1656         if (errstr != NULL)
1657                 fatal("invalid line number at line %ld: `%s' is %s\n",
1658                     p_input_line, nptr, errstr);
1659
1660         *p = c;
1661         *endptr = p;
1662
1663         return rv;
1664 }