usr.bin/patch/pch.c

   1
   2 /*-
   3  * Copyright 1986, Larry Wall
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following condition is met:
   7  * 1. Redistributions of source code must retain the above copyright notice,
   8  * this condition and the following disclaimer.
   9  *
  10  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
  11  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  12  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  13  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
  14  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  15  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  16  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  17  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  18  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  19  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  20  * SUCH DAMAGE.
  21  *
  22  * patch - a program to apply diffs to original files
  23  *
  24  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
  25  * behaviour
  26  *
  27  * $OpenBSD: pch.c,v 1.39 2012/04/11 08:07:13 ajacoutot Exp $
  28  * $FreeBSD$
  29  */
  30
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33
  34 #include <ctype.h>
  35 #include <libgen.h>
  36 #include <limits.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <unistd.h>
  41
  42 #include "common.h"
  43 #include "util.h"
  44 #include "pch.h"
  45 #include "pathnames.h"
  46
  47 /* Patch (diff listing) abstract type. */
  48
  49 static long     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 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 LINENUM  p_base;         /* where to intuit this time */
  64 static LINENUM  p_bline;        /* line # of p_base */
  65 static LINENUM  p_start;        /* where intuit found a patch */
  66 static LINENUM  p_sline;        /* and the line number for it */
  67 static LINENUM  p_hunk_beg;     /* line number of current hunk */
  68 static LINENUM  p_efake = -1;   /* end of faked up lines--don't free */
  69 static LINENUM  p_bfake = -1;   /* beg of faked up lines */
  70 static FILE     *pfp = NULL;    /* patch file pointer */
  71 static char     *bestguess = NULL;      /* guess at correct filename */
  72
  73 static void     grow_hunkmax(void);
  74 static int      intuit_diff_type(void);
  75 static void     next_intuit_at(LINENUM, LINENUM);
  76 static void     skip_to(LINENUM, LINENUM);
  77 static size_t   pgets(bool _do_indent);
  78 static char     *best_name(const struct file_name *, bool);
  79 static char     *posix_name(const struct file_name *, bool);
  80 static size_t   num_components(const char *);
  81
  82 /*
  83  * Prepare to look for the next patch in the patch file.
  84  */
  85 void
  86 re_patch(void)
  87 {
  88         p_first = 0;
  89         p_newfirst = 0;
  90         p_ptrn_lines = 0;
  91         p_repl_lines = 0;
  92         p_end = (LINENUM) - 1;
  93         p_max = 0;
  94         p_indent = 0;
  95 }
  96
  97 /*
  98  * Open the patch file at the beginning of time.
  99  */
 100 void
 101 open_patch_file(const char *filename)
 102 {
 103         struct stat filestat;
 104         int nr, nw;
 105
 106         if (filename == NULL || *filename == '\0' || strEQ(filename, "-")) {
 107                 pfp = fopen(TMPPATNAME, "w");
 108                 if (pfp == NULL)
 109                         pfatal("can't create %s", TMPPATNAME);
 110                 while ((nr = fread(buf, 1, buf_size, stdin)) > 0) {
 111                         nw = fwrite(buf, 1, nr, pfp);
 112                         if (nr != nw)
 113                                 pfatal("write error to %s", TMPPATNAME);
 114                 }
 115                 if (ferror(pfp) || fclose(pfp))
 116                         pfatal("can't write %s", TMPPATNAME);
 117                 filename = TMPPATNAME;
 118         }
 119         pfp = fopen(filename, "r");
 120         if (pfp == NULL)
 121                 pfatal("patch file %s not found", filename);
 122         fstat(fileno(pfp), &filestat);
 123         p_filesize = filestat.st_size;
 124         next_intuit_at(0L, 1L); /* start at the beginning */
 125         set_hunkmax();
 126 }
 127
 128 /*
 129  * Make sure our dynamically realloced tables are malloced to begin with.
 130  */
 131 void
 132 set_hunkmax(void)
 133 {
 134         if (p_line == NULL)
 135                 p_line = calloc((size_t) hunkmax, sizeof(char *));
 136         if (p_len == NULL)
 137                 p_len = calloc((size_t) hunkmax, sizeof(short));
 138         if (p_char == NULL)
 139                 p_char = calloc((size_t) hunkmax, sizeof(char));
 140 }
 141
 142 /*
 143  * Enlarge the arrays containing the current hunk of patch.
 144  */
 145 static void
 146 grow_hunkmax(void)
 147 {
 148         int             new_hunkmax;
 149         char            **new_p_line;
 150         short           *new_p_len;
 151         char            *new_p_char;
 152
 153         new_hunkmax = hunkmax * 2;
 154
 155         if (p_line == NULL || p_len == NULL || p_char == NULL)
 156                 fatal("Internal memory allocation error\n");
 157
 158         new_p_line = realloc(p_line, new_hunkmax * sizeof(char *));
 159         if (new_p_line == NULL)
 160                 free(p_line);
 161
 162         new_p_len = realloc(p_len, new_hunkmax * sizeof(short));
 163         if (new_p_len == NULL)
 164                 free(p_len);
 165
 166         new_p_char = realloc(p_char, new_hunkmax * sizeof(char));
 167         if (new_p_char == NULL)
 168                 free(p_char);
 169
 170         p_char = new_p_char;
 171         p_len = new_p_len;
 172         p_line = new_p_line;
 173
 174         if (p_line != NULL && p_len != NULL && p_char != NULL) {
 175                 hunkmax = new_hunkmax;
 176                 return;
 177         }
 178
 179         if (!using_plan_a)
 180                 fatal("out of memory\n");
 181         out_of_mem = true;      /* whatever is null will be allocated again */
 182                                 /* from within plan_a(), of all places */
 183 }
 184
 185 /* True if the remainder of the patch file contains a diff of some sort. */
 186
 187 bool
 188 there_is_another_patch(void)
 189 {
 190         bool exists = false;
 191
 192         if (p_base != 0L && p_base >= p_filesize) {
 193                 if (verbose)
 194                         say("done\n");
 195                 return false;
 196         }
 197         if (verbose)
 198                 say("Hmm...");
 199         diff_type = intuit_diff_type();
 200         if (!diff_type) {
 201                 if (p_base != 0L) {
 202                         if (verbose)
 203                                 say("  Ignoring the trailing garbage.\ndone\n");
 204                 } else
 205                         say("  I can't seem to find a patch in there anywhere.\n");
 206                 return false;
 207         }
 208         if (verbose)
 209                 say("  %sooks like %s to me...\n",
 210                     (p_base == 0L ? "L" : "The next patch l"),
 211                     diff_type == UNI_DIFF ? "a unified diff" :
 212                     diff_type == CONTEXT_DIFF ? "a context diff" :
 213                 diff_type == NEW_CONTEXT_DIFF ? "a new-style context diff" :
 214                     diff_type == NORMAL_DIFF ? "a normal diff" :
 215                     "an ed script");
 216         if (p_indent && verbose)
 217                 say("(Patch is indented %d space%s.)\n", p_indent,
 218                     p_indent == 1 ? "" : "s");
 219         skip_to(p_start, p_sline);
 220         while (filearg[0] == NULL) {
 221                 if (force || batch) {
 222                         say("No file to patch.  Skipping...\n");
 223                         filearg[0] = savestr(bestguess);
 224                         skip_rest_of_patch = true;
 225                         return true;
 226                 }
 227                 ask("File to patch: ");
 228                 if (*buf != '\n') {
 229                         free(bestguess);
 230                         bestguess = savestr(buf);
 231                         filearg[0] = fetchname(buf, &exists, 0);
 232                 }
 233                 if (!exists) {
 234                         ask("No file found--skip this patch? [n] ");
 235                         if (*buf != 'y')
 236                                 continue;
 237                         if (verbose)
 238                                 say("Skipping patch...\n");
 239                         free(filearg[0]);
 240                         filearg[0] = fetchname(bestguess, &exists, 0);
 241                         skip_rest_of_patch = true;
 242                         return true;
 243                 }
 244         }
 245         return true;
 246 }
 247
 248 static void
 249 p4_fetchname(struct file_name *name, char *str)
 250 {
 251         char *t, *h;
 252
 253         /* Skip leading whitespace. */
 254         while (isspace((unsigned char)*str))
 255                 str++;
 256
 257         /* Remove the file revision number. */
 258         for (t = str, h = NULL; *t != '\0' && !isspace((unsigned char)*t); t++)
 259                 if (*t == '#')
 260                         h = t;
 261         if (h != NULL)
 262                 *h = '\0';
 263
 264         name->path = fetchname(str, &name->exists, strippath);
 265 }
 266
 267 /* Determine what kind of diff is in the remaining part of the patch file. */
 268
 269 static int
 270 intuit_diff_type(void)
 271 {
 272         long    this_line = 0, previous_line;
 273         long    first_command_line = -1;
 274         LINENUM fcl_line = -1;
 275         bool    last_line_was_command = false, this_is_a_command = false;
 276         bool    stars_last_line = false, stars_this_line = false;
 277         char    *s, *t;
 278         int     indent, retval;
 279         struct file_name names[MAX_FILE];
 280
 281         memset(names, 0, sizeof(names));
 282         ok_to_create_file = false;
 283         fseek(pfp, p_base, SEEK_SET);
 284         p_input_line = p_bline - 1;
 285         for (;;) {
 286                 previous_line = this_line;
 287                 last_line_was_command = this_is_a_command;
 288                 stars_last_line = stars_this_line;
 289                 this_line = ftell(pfp);
 290                 indent = 0;
 291                 p_input_line++;
 292                 if (pgets(false) == 0) {
 293                         if (first_command_line >= 0L) {
 294                                 /* nothing but deletes!? */
 295                                 p_start = first_command_line;
 296                                 p_sline = fcl_line;
 297                                 retval = ED_DIFF;
 298                                 goto scan_exit;
 299                         } else {
 300                                 p_start = this_line;
 301                                 p_sline = p_input_line;
 302                                 retval = 0;
 303                                 goto scan_exit;
 304                         }
 305                 }
 306                 for (s = buf; *s == ' ' || *s == '\t' || *s == 'X'; s++) {
 307                         if (*s == '\t')
 308                                 indent += 8 - (indent % 8);
 309                         else
 310                                 indent++;
 311                 }
 312                 for (t = s; isdigit((unsigned char)*t) || *t == ','; t++)
 313                         ;
 314                 this_is_a_command = (isdigit((unsigned char)*s) &&
 315                     (*t == 'd' || *t == 'c' || *t == 'a'));
 316                 if (first_command_line < 0L && this_is_a_command) {
 317                         first_command_line = this_line;
 318                         fcl_line = p_input_line;
 319                         p_indent = indent;      /* assume this for now */
 320                 }
 321                 if (!stars_last_line && strnEQ(s, "*** ", 4))
 322                         names[OLD_FILE].path = fetchname(s + 4,
 323                             &names[OLD_FILE].exists, strippath);
 324                 else if (strnEQ(s, "--- ", 4))
 325                         names[NEW_FILE].path = fetchname(s + 4,
 326                             &names[NEW_FILE].exists, strippath);
 327                 else if (strnEQ(s, "+++ ", 4))
 328                         /* pretend it is the old name */
 329                         names[OLD_FILE].path = fetchname(s + 4,
 330                             &names[OLD_FILE].exists, strippath);
 331                 else if (strnEQ(s, "Index:", 6))
 332                         names[INDEX_FILE].path = fetchname(s + 6,
 333                             &names[INDEX_FILE].exists, strippath);
 334                 else if (strnEQ(s, "Prereq:", 7)) {
 335                         for (t = s + 7; isspace((unsigned char)*t); t++)
 336                                 ;
 337                         revision = savestr(t);
 338                         for (t = revision; *t && !isspace((unsigned char)*t); t++)
 339                                 ;
 340                         *t = '\0';
 341                         if (*revision == '\0') {
 342                                 free(revision);
 343                                 revision = NULL;
 344                         }
 345                 } else if (strnEQ(s, "==== ", 5)) {
 346                         /* Perforce-style diffs. */
 347                         if ((t = strstr(s + 5, " - ")) != NULL)
 348                                 p4_fetchname(&names[NEW_FILE], t + 3);
 349                         p4_fetchname(&names[OLD_FILE], s + 5);
 350                 }
 351                 if ((!diff_type || diff_type == ED_DIFF) &&
 352                     first_command_line >= 0L &&
 353                     strEQ(s, ".\n")) {
 354                         p_indent = indent;
 355                         p_start = first_command_line;
 356                         p_sline = fcl_line;
 357                         retval = ED_DIFF;
 358                         goto scan_exit;
 359                 }
 360                 if ((!diff_type || diff_type == UNI_DIFF) && strnEQ(s, "@@ -", 4)) {
 361                         if (strnEQ(s + 4, "0,0", 3))
 362                                 ok_to_create_file = true;
 363                         p_indent = indent;
 364                         p_start = this_line;
 365                         p_sline = p_input_line;
 366                         retval = UNI_DIFF;
 367                         goto scan_exit;
 368                 }
 369                 stars_this_line = strnEQ(s, "********", 8);
 370                 if ((!diff_type || diff_type == CONTEXT_DIFF) && stars_last_line &&
 371                     strnEQ(s, "*** ", 4)) {
 372                         if (atol(s + 4) == 0)
 373                                 ok_to_create_file = true;
 374                         /*
 375                          * If this is a new context diff the character just
 376                          * before the newline is a '*'.
 377                          */
 378                         while (*s != '\n')
 379                                 s++;
 380                         p_indent = indent;
 381                         p_start = previous_line;
 382                         p_sline = p_input_line - 1;
 383                         retval = (*(s - 1) == '*' ? NEW_CONTEXT_DIFF : CONTEXT_DIFF);
 384                         goto scan_exit;
 385                 }
 386                 if ((!diff_type || diff_type == NORMAL_DIFF) &&
 387                     last_line_was_command &&
 388                     (strnEQ(s, "< ", 2) || strnEQ(s, "> ", 2))) {
 389                         p_start = previous_line;
 390                         p_sline = p_input_line - 1;
 391                         p_indent = indent;
 392                         retval = NORMAL_DIFF;
 393                         goto scan_exit;
 394                 }
 395         }
 396 scan_exit:
 397         if (retval == UNI_DIFF) {
 398                 /* unswap old and new */
 399                 struct file_name tmp = names[OLD_FILE];
 400                 names[OLD_FILE] = names[NEW_FILE];
 401                 names[NEW_FILE] = tmp;
 402         }
 403         if (filearg[0] == NULL) {
 404                 if (posix)
 405                         filearg[0] = posix_name(names, ok_to_create_file);
 406                 else {
 407                         /* Ignore the Index: name for context diffs, like GNU */
 408                         if (names[OLD_FILE].path != NULL ||
 409                             names[NEW_FILE].path != NULL) {
 410                                 free(names[INDEX_FILE].path);
 411                                 names[INDEX_FILE].path = NULL;
 412                         }
 413                         filearg[0] = best_name(names, ok_to_create_file);
 414                 }
 415         }
 416
 417         free(bestguess);
 418         bestguess = NULL;
 419         if (filearg[0] != NULL)
 420                 bestguess = savestr(filearg[0]);
 421         else if (!ok_to_create_file) {
 422                 /*
 423                  * We don't want to create a new file but we need a
 424                  * filename to set bestguess.  Avoid setting filearg[0]
 425                  * so the file is not created automatically.
 426                  */
 427                 if (posix)
 428                         bestguess = posix_name(names, true);
 429                 else
 430                         bestguess = best_name(names, true);
 431         }
 432         free(names[OLD_FILE].path);
 433         free(names[NEW_FILE].path);
 434         free(names[INDEX_FILE].path);
 435         return retval;
 436 }
 437
 438 /*
 439  * Remember where this patch ends so we know where to start up again.
 440  */
 441 static void
 442 next_intuit_at(LINENUM file_pos, LINENUM file_line)
 443 {
 444         p_base = file_pos;
 445         p_bline = file_line;
 446 }
 447
 448 /*
 449  * Basically a verbose fseek() to the actual diff listing.
 450  */
 451 static void
 452 skip_to(LINENUM file_pos, LINENUM file_line)
 453 {
 454         size_t  len;
 455
 456         if (p_base > file_pos)
 457                 fatal("Internal error: seek %ld>%ld\n", p_base, file_pos);
 458         if (verbose && p_base < file_pos) {
 459                 fseek(pfp, p_base, SEEK_SET);
 460                 say("The text leading up to this was:\n--------------------------\n");
 461                 while (ftell(pfp) < file_pos) {
 462                         len = pgets(false);
 463                         if (len == 0)
 464                                 fatal("Unexpected end of file\n");
 465                         say("|%s", buf);
 466                 }
 467                 say("--------------------------\n");
 468         } else
 469                 fseek(pfp, file_pos, SEEK_SET);
 470         p_input_line = file_line - 1;
 471 }
 472
 473 /* Make this a function for better debugging.  */
 474 static void
 475 malformed(void)
 476 {
 477         fatal("malformed patch at line %ld: %s", p_input_line, buf);
 478         /* about as informative as "Syntax error" in C */
 479 }
 480
 481 /*
 482  * True if the line has been discarded (i.e. it is a line saying
 483  *  "\ No newline at end of file".)
 484  */
 485 static bool
 486 remove_special_line(void)
 487 {
 488         int     c;
 489
 490         c = fgetc(pfp);
 491         if (c == '\\') {
 492                 do {
 493                         c = fgetc(pfp);
 494                 } while (c != EOF && c != '\n');
 495
 496                 return true;
 497         }
 498         if (c != EOF)
 499                 fseek(pfp, -1L, SEEK_CUR);
 500
 501         return false;
 502 }
 503
 504 /*
 505  * True if there is more of the current diff listing to process.
 506  */
 507 bool
 508 another_hunk(void)
 509 {
 510         long    line_beginning;                 /* file pos of the current line */
 511         LINENUM repl_beginning;                 /* index of --- line */
 512         LINENUM fillcnt;                        /* #lines of missing ptrn or repl */
 513         LINENUM fillsrc;                        /* index of first line to copy */
 514         LINENUM filldst;                        /* index of first missing line */
 515         bool    ptrn_spaces_eaten;              /* ptrn was slightly misformed */
 516         bool    repl_could_be_missing;          /* no + or ! lines in this hunk */
 517         bool    repl_missing;                   /* we are now backtracking */
 518         long    repl_backtrack_position;        /* file pos of first repl line */
 519         LINENUM repl_patch_line;                /* input line number for same */
 520         LINENUM ptrn_copiable;                  /* # of copiable lines in ptrn */
 521         char    *s;
 522         size_t  len;
 523         int     context = 0;
 524
 525         while (p_end >= 0) {
 526                 if (p_end == p_efake)
 527                         p_end = p_bfake;        /* don't free twice */
 528                 else
 529                         free(p_line[p_end]);
 530                 p_end--;
 531         }
 532         p_efake = -1;
 533
 534         p_max = hunkmax;        /* gets reduced when --- found */
 535         if (diff_type == CONTEXT_DIFF || diff_type == NEW_CONTEXT_DIFF) {
 536                 line_beginning = ftell(pfp);
 537                 repl_beginning = 0;
 538                 fillcnt = 0;
 539                 fillsrc = 0;
 540                 filldst = 0;
 541                 ptrn_spaces_eaten = false;
 542                 repl_could_be_missing = true;
 543                 repl_missing = false;
 544                 repl_backtrack_position = 0;
 545                 repl_patch_line = 0;
 546                 ptrn_copiable = 0;
 547
 548                 len = pgets(true);
 549                 p_input_line++;
 550                 if (len == 0 || strnNE(buf, "********", 8)) {
 551                         next_intuit_at(line_beginning, p_input_line);
 552                         return false;
 553                 }
 554                 p_context = 100;
 555                 p_hunk_beg = p_input_line + 1;
 556                 while (p_end < p_max) {
 557                         line_beginning = ftell(pfp);
 558                         len = pgets(true);
 559                         p_input_line++;
 560                         if (len == 0) {
 561                                 if (p_max - p_end < 4) {
 562                                         /* assume blank lines got chopped */
 563                                         strlcpy(buf, "  \n", buf_size);
 564                                 } else {
 565                                         if (repl_beginning && repl_could_be_missing) {
 566                                                 repl_missing = true;
 567                                                 goto hunk_done;
 568                                         }
 569                                         fatal("unexpected end of file in patch\n");
 570                                 }
 571                         }
 572                         p_end++;
 573                         if (p_end >= hunkmax)
 574                                 fatal("Internal error: hunk larger than hunk "
 575                                     "buffer size");
 576                         p_char[p_end] = *buf;
 577                         p_line[p_end] = NULL;
 578                         switch (*buf) {
 579                         case '*':
 580                                 if (strnEQ(buf, "********", 8)) {
 581                                         if (repl_beginning && repl_could_be_missing) {
 582                                                 repl_missing = true;
 583                                                 goto hunk_done;
 584                                         } else
 585                                                 fatal("unexpected end of hunk "
 586                                                     "at line %ld\n",
 587                                                     p_input_line);
 588                                 }
 589                                 if (p_end != 0) {
 590                                         if (repl_beginning && repl_could_be_missing) {
 591                                                 repl_missing = true;
 592                                                 goto hunk_done;
 593                                         }
 594                                         fatal("unexpected *** at line %ld: %s",
 595                                             p_input_line, buf);
 596                                 }
 597                                 context = 0;
 598                                 p_line[p_end] = savestr(buf);
 599                                 if (out_of_mem) {
 600                                         p_end--;
 601                                         return false;
 602                                 }
 603                                 for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 604                                         ;
 605                                 if (!*s)
 606                                         malformed();
 607                                 if (strnEQ(s, "0,0", 3))
 608                                         memmove(s, s + 2, strlen(s + 2) + 1);
 609                                 p_first = (LINENUM) atol(s);
 610                                 while (isdigit((unsigned char)*s))
 611                                         s++;
 612                                 if (*s == ',') {
 613                                         for (; *s && !isdigit((unsigned char)*s); s++)
 614                                                 ;
 615                                         if (!*s)
 616                                                 malformed();
 617                                         p_ptrn_lines = ((LINENUM) atol(s)) - p_first + 1;
 618                                 } else if (p_first)
 619                                         p_ptrn_lines = 1;
 620                                 else {
 621                                         p_ptrn_lines = 0;
 622                                         p_first = 1;
 623                                 }
 624
 625                                 /* we need this much at least */
 626                                 p_max = p_ptrn_lines + 6;
 627                                 while (p_max >= hunkmax)
 628                                         grow_hunkmax();
 629                                 p_max = hunkmax;
 630                                 break;
 631                         case '-':
 632                                 if (buf[1] == '-') {
 633                                         if (repl_beginning ||
 634                                             (p_end != p_ptrn_lines + 1 +
 635                                             (p_char[p_end - 1] == '\n'))) {
 636                                                 if (p_end == 1) {
 637                                                         /*
 638                                                          * `old' lines were omitted;
 639                                                          * set up to fill them in
 640                                                          * from 'new' context lines.
 641                                                          */
 642                                                         p_end = p_ptrn_lines + 1;
 643                                                         fillsrc = p_end + 1;
 644                                                         filldst = 1;
 645                                                         fillcnt = p_ptrn_lines;
 646                                                 } else {
 647                                                         if (repl_beginning) {
 648                                                                 if (repl_could_be_missing) {
 649                                                                         repl_missing = true;
 650                                                                         goto hunk_done;
 651                                                                 }
 652                                                                 fatal("duplicate \"---\" at line %ld--check line numbers at line %ld\n",
 653                                                                     p_input_line, p_hunk_beg + repl_beginning);
 654                                                         } else {
 655                                                                 fatal("%s \"---\" at line %ld--check line numbers at line %ld\n",
 656                                                                     (p_end <= p_ptrn_lines
 657                                                                     ? "Premature"
 658                                                                     : "Overdue"),
 659                                                                     p_input_line, p_hunk_beg);
 660                                                         }
 661                                                 }
 662                                         }
 663                                         repl_beginning = p_end;
 664                                         repl_backtrack_position = ftell(pfp);
 665                                         repl_patch_line = p_input_line;
 666                                         p_line[p_end] = savestr(buf);
 667                                         if (out_of_mem) {
 668                                                 p_end--;
 669                                                 return false;
 670                                         }
 671                                         p_char[p_end] = '=';
 672                                         for (s = buf; *s && !isdigit((unsigned char)*s); s++)
 673                                                 ;
 674                                         if (!*s)
 675                                                 malformed();
 676                                         p_newfirst = (LINENUM) atol(s);
 677                                         while (isdigit((unsigned char)*s))
 678                                                 s++;
 679                                         if (*s == ',') {
 680                                                 for (; *s && !isdigit((unsigned char)*s); s++)
 681                                                         ;
 682                                                 if (!*s)
 683                                                         malformed();
 684                                                 p_repl_lines = ((LINENUM) atol(s)) -
 685                                                     p_newfirst + 1;
 686                                         } else if (p_newfirst)
 687                                                 p_repl_lines = 1;
 688                                         else {
 689                                                 p_repl_lines = 0;
 690                                                 p_newfirst = 1;
 691                                         }
 692                                         p_max = p_repl_lines + p_end;
 693                                         if (p_max > MAXHUNKSIZE)
 694                                                 fatal("hunk too large (%ld lines) at line %ld: %s",
 695                                                     p_max, p_input_line, buf);
 696                                         while (p_max >= hunkmax)
 697                                                 grow_hunkmax();
 698                                         if (p_repl_lines != ptrn_copiable &&
 699                                             (p_context != 0 || p_repl_lines != 1))
 700                                                 repl_could_be_missing = false;
 701                                         break;
 702                                 }
 703                                 goto change_line;
 704                         case '+':
 705                         case '!':
 706                                 repl_could_be_missing = false;
 707                 change_line:
 708                                 if (buf[1] == '\n' && canonicalize)
 709                                         strlcpy(buf + 1, " \n", buf_size - 1);
 710                                 if (!isspace((unsigned char)buf[1]) && buf[1] != '>' &&
 711                                     buf[1] != '<' &&
 712                                     repl_beginning && repl_could_be_missing) {
 713                                         repl_missing = true;
 714                                         goto hunk_done;
 715                                 }
 716                                 if (context >= 0) {
 717                                         if (context < p_context)
 718                                                 p_context = context;
 719                                         context = -1000;
 720                                 }
 721                                 p_line[p_end] = savestr(buf + 2);
 722                                 if (out_of_mem) {
 723                                         p_end--;
 724                                         return false;
 725                                 }
 726                                 if (p_end == p_ptrn_lines) {
 727                                         if (remove_special_line()) {
 728                                                 int     l;
 729
 730                                                 l = strlen(p_line[p_end]) - 1;
 731                                                 (p_line[p_end])[l] = 0;
 732                                         }
 733                                 }
 734                                 break;
 735                         case '\t':
 736                         case '\n':      /* assume the 2 spaces got eaten */
 737                                 if (repl_beginning && repl_could_be_missing &&
 738                                     (!ptrn_spaces_eaten ||
 739                                     diff_type == NEW_CONTEXT_DIFF)) {
 740                                         repl_missing = true;
 741                                         goto hunk_done;
 742                                 }
 743                                 p_line[p_end] = savestr(buf);
 744                                 if (out_of_mem) {
 745                                         p_end--;
 746                                         return false;
 747                                 }
 748                                 if (p_end != p_ptrn_lines + 1) {
 749                                         ptrn_spaces_eaten |= (repl_beginning != 0);
 750                                         context++;
 751                                         if (!repl_beginning)
 752                                                 ptrn_copiable++;
 753                                         p_char[p_end] = ' ';
 754                                 }
 755                                 break;
 756                         case ' ':
 757                                 if (!isspace((unsigned char)buf[1]) &&
 758                                     repl_beginning && repl_could_be_missing) {
 759                                         repl_missing = true;
 760                                         goto hunk_done;
 761                                 }
 762                                 context++;
 763                                 if (!repl_beginning)
 764                                         ptrn_copiable++;
 765                                 p_line[p_end] = savestr(buf + 2);
 766                                 if (out_of_mem) {
 767                                         p_end--;
 768                                         return false;
 769                                 }
 770                                 break;
 771                         default:
 772                                 if (repl_beginning && repl_could_be_missing) {
 773                                         repl_missing = true;
 774                                         goto hunk_done;
 775                                 }
 776                                 malformed();
 777                         }
 778                         /* set up p_len for strncmp() so we don't have to */
 779                         /* assume null termination */
 780                         if (p_line[p_end])
 781                                 p_len[p_end] = strlen(p_line[p_end]);
 782                         else
 783                                 p_len[p_end] = 0;
 784                 }
 785
 786 hunk_done:
 787                 if (p_end >= 0 && !repl_beginning)
 788                         fatal("no --- found in patch at line %ld\n", pch_hunk_beg());
 789
 790                 if (repl_missing) {
 791
 792                         /* reset state back to just after --- */
 793                         p_input_line = repl_patch_line;
 794                         for (p_end--; p_end > repl_beginning; p_end--)
 795                                 free(p_line[p_end]);
 796                         fseek(pfp, repl_backtrack_position, SEEK_SET);
 797
 798                         /* redundant 'new' context lines were omitted - set */
 799                         /* up to fill them in from the old file context */
 800                         if (!p_context && p_repl_lines == 1) {
 801                                 p_repl_lines = 0;
 802                                 p_max--;
 803                         }
 804                         fillsrc = 1;
 805                         filldst = repl_beginning + 1;
 806                         fillcnt = p_repl_lines;
 807                         p_end = p_max;
 808                 } else if (!p_context && fillcnt == 1) {
 809                         /* the first hunk was a null hunk with no context */
 810                         /* and we were expecting one line -- fix it up. */
 811                         while (filldst < p_end) {
 812                                 p_line[filldst] = p_line[filldst + 1];
 813                                 p_char[filldst] = p_char[filldst + 1];
 814                                 p_len[filldst] = p_len[filldst + 1];
 815                                 filldst++;
 816                         }
 817 #if 0
 818                         repl_beginning--;       /* this doesn't need to be fixed */
 819 #endif
 820                         p_end--;
 821                         p_first++;      /* do append rather than insert */
 822                         fillcnt = 0;
 823                         p_ptrn_lines = 0;
 824                 }
 825                 if (diff_type == CONTEXT_DIFF &&
 826                     (fillcnt || (p_first > 1 && ptrn_copiable > 2 * p_context))) {
 827                         if (verbose)
 828                                 say("%s\n%s\n%s\n",
 829                                     "(Fascinating--this is really a new-style context diff but without",
 830                                     "the telltale extra asterisks on the *** line that usually indicate",
 831                                     "the new style...)");
 832                         diff_type = NEW_CONTEXT_DIFF;
 833                 }
 834                 /* if there were omitted context lines, fill them in now */
 835                 if (fillcnt) {
 836                         p_bfake = filldst;      /* remember where not to free() */
 837                         p_efake = filldst + fillcnt - 1;
 838                         while (fillcnt-- > 0) {
 839                                 while (fillsrc <= p_end && p_char[fillsrc] != ' ')
 840                                         fillsrc++;
 841                                 if (fillsrc > p_end)
 842                                         fatal("replacement text or line numbers mangled in hunk at line %ld\n",
 843                                             p_hunk_beg);
 844                                 p_line[filldst] = p_line[fillsrc];
 845                                 p_char[filldst] = p_char[fillsrc];
 846                                 p_len[filldst] = p_len[fillsrc];
 847                                 fillsrc++;
 848                                 filldst++;
 849                         }
 850                         while (fillsrc <= p_end && fillsrc != repl_beginning &&
 851                             p_char[fillsrc] != ' ')
 852                                 fillsrc++;
 853 #ifdef DEBUGGING
 854                         if (debug & 64)
 855                                 printf("fillsrc %ld, filldst %ld, rb %ld, e+1 %ld\n",
 856                                 fillsrc, filldst, repl_beginning, p_end + 1);
 857 #endif
 858                         if (fillsrc != p_end + 1 && fillsrc != repl_beginning)
 859                                 malformed();
 860                         if (filldst != p_end + 1 && filldst != repl_beginning)
 861                                 malformed();
 862                 }
 863                 if (p_line[p_end] != NULL) {
 864                         if (remove_special_line()) {
 865                                 p_len[p_end] -= 1;
 866                                 (p_line[p_end])[p_len[p_end]] = 0;
 867                         }
 868                 }
 869         } else if (diff_type == UNI_DIFF) {
 870                 LINENUM fillold;        /* index of old lines */
 871                 LINENUM fillnew;        /* index of new lines */
 872                 char    ch;
 873
 874                 line_beginning = ftell(pfp); /* file pos of the current line */
 875                 len = pgets(true);
 876                 p_input_line++;
 877                 if (len == 0 || strnNE(buf, "@@ -", 4)) {
 878                         next_intuit_at(line_beginning, p_input_line);
 879                         return false;
 880                 }
 881                 s = buf + 4;
 882                 if (!*s)
 883                         malformed();
 884                 p_first = (LINENUM) atol(s);
 885                 while (isdigit((unsigned char)*s))
 886                         s++;
 887                 if (*s == ',') {
 888                         p_ptrn_lines = (LINENUM) atol(++s);
 889                         while (isdigit((unsigned char)*s))
 890                                 s++;
 891                 } else
 892                         p_ptrn_lines = 1;
 893                 if (*s == ' ')
 894                         s++;
 895                 if (*s != '+' || !*++s)
 896                         malformed();
 897                 p_newfirst = (LINENUM) atol(s);
 898                 while (isdigit((unsigned char)*s))
 899                         s++;
 900                 if (*s == ',') {
 901                         p_repl_lines = (LINENUM) atol(++s);
 902                         while (isdigit((unsigned char)*s))
 903                                 s++;
 904                 } else
 905                         p_repl_lines = 1;
 906                 if (*s == ' ')
 907                         s++;
 908                 if (*s != '@')
 909                         malformed();
 910                 if (!p_ptrn_lines)
 911                         p_first++;      /* do append rather than insert */
 912                 p_max = p_ptrn_lines + p_repl_lines + 1;
 913                 while (p_max >= hunkmax)
 914                         grow_hunkmax();
 915                 fillold = 1;
 916                 fillnew = fillold + p_ptrn_lines;
 917                 p_end = fillnew + p_repl_lines;
 918                 snprintf(buf, buf_size, "*** %ld,%ld ****\n", p_first,
 919                     p_first + p_ptrn_lines - 1);
 920                 p_line[0] = savestr(buf);
 921                 if (out_of_mem) {
 922                         p_end = -1;
 923                         return false;
 924                 }
 925                 p_char[0] = '*';
 926                 snprintf(buf, buf_size, "--- %ld,%ld ----\n", p_newfirst,
 927                     p_newfirst + p_repl_lines - 1);
 928                 p_line[fillnew] = savestr(buf);
 929                 if (out_of_mem) {
 930                         p_end = 0;
 931                         return false;
 932                 }
 933                 p_char[fillnew++] = '=';
 934                 p_context = 100;
 935                 context = 0;
 936                 p_hunk_beg = p_input_line + 1;
 937                 while (fillold <= p_ptrn_lines || fillnew <= p_end) {
 938                         line_beginning = ftell(pfp);
 939                         len = pgets(true);
 940                         p_input_line++;
 941                         if (len == 0) {
 942                                 if (p_max - fillnew < 3) {
 943                                         /* assume blank lines got chopped */
 944                                         strlcpy(buf, " \n", buf_size);
 945                                 } else {
 946                                         fatal("unexpected end of file in patch\n");
 947                                 }
 948                         }
 949                         if (*buf == '\t' || *buf == '\n') {
 950                                 ch = ' ';       /* assume the space got eaten */
 951                                 s = savestr(buf);
 952                         } else {
 953                                 ch = *buf;
 954                                 s = savestr(buf + 1);
 955                         }
 956                         if (out_of_mem) {
 957                                 while (--fillnew > p_ptrn_lines)
 958                                         free(p_line[fillnew]);
 959                                 p_end = fillold - 1;
 960                                 return false;
 961                         }
 962                         switch (ch) {
 963                         case '-':
 964                                 if (fillold > p_ptrn_lines) {
 965                                         free(s);
 966                                         p_end = fillnew - 1;
 967                                         malformed();
 968                                 }
 969                                 p_char[fillold] = ch;
 970                                 p_line[fillold] = s;
 971                                 p_len[fillold++] = strlen(s);
 972                                 if (fillold > p_ptrn_lines) {
 973                                         if (remove_special_line()) {
 974                                                 p_len[fillold - 1] -= 1;
 975                                                 s[p_len[fillold - 1]] = 0;
 976                                         }
 977                                 }
 978                                 break;
 979                         case '=':
 980                                 ch = ' ';
 981                                 /* FALL THROUGH */
 982                         case ' ':
 983                                 if (fillold > p_ptrn_lines) {
 984                                         free(s);
 985                                         while (--fillnew > p_ptrn_lines)
 986                                                 free(p_line[fillnew]);
 987                                         p_end = fillold - 1;
 988                                         malformed();
 989                                 }
 990                                 context++;
 991                                 p_char[fillold] = ch;
 992                                 p_line[fillold] = s;
 993                                 p_len[fillold++] = strlen(s);
 994                                 s = savestr(s);
 995                                 if (out_of_mem) {
 996                                         while (--fillnew > p_ptrn_lines)
 997                                                 free(p_line[fillnew]);
 998                                         p_end = fillold - 1;
 999                                         return false;
1000                                 }
1001                                 if (fillold > p_ptrn_lines) {
1002                                         if (remove_special_line()) {
1003                                                 p_len[fillold - 1] -= 1;
1004                                                 s[p_len[fillold - 1]] = 0;
1005                                         }
1006                                 }
1007                                 /* FALL THROUGH */
1008                         case '+':
1009                                 if (fillnew > p_end) {
1010                                         free(s);
1011                                         while (--fillnew > p_ptrn_lines)
1012                                                 free(p_line[fillnew]);
1013                                         p_end = fillold - 1;
1014                                         malformed();
1015                                 }
1016                                 p_char[fillnew] = ch;
1017                                 p_line[fillnew] = s;
1018                                 p_len[fillnew++] = strlen(s);
1019                                 if (fillold > p_ptrn_lines) {
1020                                         if (remove_special_line()) {
1021                                                 p_len[fillnew - 1] -= 1;
1022                                                 s[p_len[fillnew - 1]] = 0;
1023                                         }
1024                                 }
1025                                 break;
1026                         default:
1027                                 p_end = fillnew;
1028                                 malformed();
1029                         }
1030                         if (ch != ' ' && context > 0) {
1031                                 if (context < p_context)
1032                                         p_context = context;
1033                                 context = -1000;
1034                         }
1035                 }               /* while */
1036         } else {                /* normal diff--fake it up */
1037                 char    hunk_type;
1038                 int     i;
1039                 LINENUM min, max;
1040
1041                 line_beginning = ftell(pfp);
1042                 p_context = 0;
1043                 len = pgets(true);
1044                 p_input_line++;
1045                 if (len == 0 || !isdigit((unsigned char)*buf)) {
1046                         next_intuit_at(line_beginning, p_input_line);
1047                         return false;
1048                 }
1049                 p_first = (LINENUM) atol(buf);
1050                 for (s = buf; isdigit((unsigned char)*s); s++)
1051                         ;
1052                 if (*s == ',') {
1053                         p_ptrn_lines = (LINENUM) atol(++s) - p_first + 1;
1054                         while (isdigit((unsigned char)*s))
1055                                 s++;
1056                 } else
1057                         p_ptrn_lines = (*s != 'a');
1058                 hunk_type = *s;
1059                 if (hunk_type == 'a')
1060                         p_first++;      /* do append rather than insert */
1061                 min = (LINENUM) atol(++s);
1062                 for (; isdigit((unsigned char)*s); s++)
1063                         ;
1064                 if (*s == ',')
1065                         max = (LINENUM) atol(++s);
1066                 else
1067                         max = min;
1068                 if (hunk_type == 'd')
1069                         min++;
1070                 p_end = p_ptrn_lines + 1 + max - min + 1;
1071                 if (p_end > MAXHUNKSIZE)
1072                         fatal("hunk too large (%ld lines) at line %ld: %s",
1073                             p_end, p_input_line, buf);
1074                 while (p_end >= hunkmax)
1075                         grow_hunkmax();
1076                 p_newfirst = min;
1077                 p_repl_lines = max - min + 1;
1078                 snprintf(buf, buf_size, "*** %ld,%ld\n", p_first,
1079                     p_first + p_ptrn_lines - 1);
1080                 p_line[0] = savestr(buf);
1081                 if (out_of_mem) {
1082                         p_end = -1;
1083                         return false;
1084                 }
1085                 p_char[0] = '*';
1086                 for (i = 1; i <= p_ptrn_lines; i++) {
1087                         len = pgets(true);
1088                         p_input_line++;
1089                         if (len == 0)
1090                                 fatal("unexpected end of file in patch at line %ld\n",
1091                                     p_input_line);
1092                         if (*buf != '<')
1093                                 fatal("< expected at line %ld of patch\n",
1094                                     p_input_line);
1095                         p_line[i] = savestr(buf + 2);
1096                         if (out_of_mem) {
1097                                 p_end = i - 1;
1098                                 return false;
1099                         }
1100                         p_len[i] = strlen(p_line[i]);
1101                         p_char[i] = '-';
1102                 }
1103
1104                 if (remove_special_line()) {
1105                         p_len[i - 1] -= 1;
1106                         (p_line[i - 1])[p_len[i - 1]] = 0;
1107                 }
1108                 if (hunk_type == 'c') {
1109                         len = pgets(true);
1110                         p_input_line++;
1111                         if (len == 0)
1112                                 fatal("unexpected end of file in patch at line %ld\n",
1113                                     p_input_line);
1114                         if (*buf != '-')
1115                                 fatal("--- expected at line %ld of patch\n",
1116                                     p_input_line);
1117                 }
1118                 snprintf(buf, buf_size, "--- %ld,%ld\n", min, max);
1119                 p_line[i] = savestr(buf);
1120                 if (out_of_mem) {
1121                         p_end = i - 1;
1122                         return false;
1123                 }
1124                 p_char[i] = '=';
1125                 for (i++; i <= p_end; i++) {
1126                         len = pgets(true);
1127                         p_input_line++;
1128                         if (len == 0)
1129                                 fatal("unexpected end of file in patch at line %ld\n",
1130                                     p_input_line);
1131                         if (*buf != '>')
1132                                 fatal("> expected at line %ld of patch\n",
1133                                     p_input_line);
1134                         p_line[i] = savestr(buf + 2);
1135                         if (out_of_mem) {
1136                                 p_end = i - 1;
1137                                 return false;
1138                         }
1139                         p_len[i] = strlen(p_line[i]);
1140                         p_char[i] = '+';
1141                 }
1142
1143                 if (remove_special_line()) {
1144                         p_len[i - 1] -= 1;
1145                         (p_line[i - 1])[p_len[i - 1]] = 0;
1146                 }
1147         }
1148         if (reverse)            /* backwards patch? */
1149                 if (!pch_swap())
1150                         say("Not enough memory to swap next hunk!\n");
1151 #ifdef DEBUGGING
1152         if (debug & 2) {
1153                 int     i;
1154                 char    special;
1155
1156                 for (i = 0; i <= p_end; i++) {
1157                         if (i == p_ptrn_lines)
1158                                 special = '^';
1159                         else
1160                                 special = ' ';
1161                         fprintf(stderr, "%3d %c %c %s", i, p_char[i],
1162                             special, p_line[i]);
1163                         fflush(stderr);
1164                 }
1165         }
1166 #endif
1167         if (p_end + 1 < hunkmax)/* paranoia reigns supreme... */
1168                 p_char[p_end + 1] = '^';        /* add a stopper for apply_hunk */
1169         return true;
1170 }
1171
1172 /*
1173  * Input a line from the patch file.
1174  * Worry about indentation if do_indent is true.
1175  * The line is read directly into the buf global variable which
1176  * is resized if necessary in order to hold the complete line.
1177  * Returns the number of characters read including the terminating
1178  * '\n', if any.
1179  */
1180 size_t
1181 pgets(bool do_indent)
1182 {
1183         char *line;
1184         size_t len;
1185         int indent = 0, skipped = 0;
1186
1187         line = fgetln(pfp, &len);
1188         if (line != NULL) {
1189                 if (len + 1 > buf_size) {
1190                         while (len + 1 > buf_size)
1191                                 buf_size *= 2;
1192                         free(buf);
1193                         buf = malloc(buf_size);
1194                         if (buf == NULL)
1195                                 fatal("out of memory\n");
1196                 }
1197                 if (do_indent == 1 && p_indent) {
1198                         for (;
1199                             indent < p_indent && (*line == ' ' || *line == '\t' || *line == 'X');
1200                             line++, skipped++) {
1201                                 if (*line == '\t')
1202                                         indent += 8 - (indent %7);
1203                                 else
1204                                         indent++;
1205                         }
1206                 }
1207                 memcpy(buf, line, len - skipped);
1208                 buf[len - skipped] = '\0';
1209         }
1210         return len;
1211 }
1212
1213
1214 /*
1215  * Reverse the old and new portions of the current hunk.
1216  */
1217 bool
1218 pch_swap(void)
1219 {
1220         char    **tp_line;      /* the text of the hunk */
1221         short   *tp_len;        /* length of each line */
1222         char    *tp_char;       /* +, -, and ! */
1223         LINENUM i;
1224         LINENUM n;
1225         bool    blankline = false;
1226         char    *s;
1227
1228         i = p_first;
1229         p_first = p_newfirst;
1230         p_newfirst = i;
1231
1232         /* make a scratch copy */
1233
1234         tp_line = p_line;
1235         tp_len = p_len;
1236         tp_char = p_char;
1237         p_line = NULL;  /* force set_hunkmax to allocate again */
1238         p_len = NULL;
1239         p_char = NULL;
1240         set_hunkmax();
1241         if (p_line == NULL || p_len == NULL || p_char == NULL) {
1242
1243                 free(p_line);
1244                 p_line = tp_line;
1245                 free(p_len);
1246                 p_len = tp_len;
1247                 free(p_char);
1248                 p_char = tp_char;
1249                 return false;   /* not enough memory to swap hunk! */
1250         }
1251         /* now turn the new into the old */
1252
1253         i = p_ptrn_lines + 1;
1254         if (tp_char[i] == '\n') {       /* account for possible blank line */
1255                 blankline = true;
1256                 i++;
1257         }
1258         if (p_efake >= 0) {     /* fix non-freeable ptr range */
1259                 if (p_efake <= i)
1260                         n = p_end - i + 1;
1261                 else
1262                         n = -i;
1263                 p_efake += n;
1264                 p_bfake += n;
1265         }
1266         for (n = 0; i <= p_end; i++, n++) {
1267                 p_line[n] = tp_line[i];
1268                 p_char[n] = tp_char[i];
1269                 if (p_char[n] == '+')
1270                         p_char[n] = '-';
1271                 p_len[n] = tp_len[i];
1272         }
1273         if (blankline) {
1274                 i = p_ptrn_lines + 1;
1275                 p_line[n] = tp_line[i];
1276                 p_char[n] = tp_char[i];
1277                 p_len[n] = tp_len[i];
1278                 n++;
1279         }
1280         if (p_char[0] != '=')
1281                 fatal("Malformed patch at line %ld: expected '=' found '%c'\n",
1282                     p_input_line, p_char[0]);
1283         p_char[0] = '*';
1284         for (s = p_line[0]; *s; s++)
1285                 if (*s == '-')
1286                         *s = '*';
1287
1288         /* now turn the old into the new */
1289
1290         if (p_char[0] != '*')
1291                 fatal("Malformed patch at line %ld: expected '*' found '%c'\n",
1292                     p_input_line, p_char[0]);
1293         tp_char[0] = '=';
1294         for (s = tp_line[0]; *s; s++)
1295                 if (*s == '*')
1296                         *s = '-';
1297         for (i = 0; n <= p_end; i++, n++) {
1298                 p_line[n] = tp_line[i];
1299                 p_char[n] = tp_char[i];
1300                 if (p_char[n] == '-')
1301                         p_char[n] = '+';
1302                 p_len[n] = tp_len[i];
1303         }
1304
1305         if (i != p_ptrn_lines + 1)
1306                 fatal("Malformed patch at line %ld: expected %ld lines, "
1307                     "got %ld\n",
1308                     p_input_line, p_ptrn_lines + 1, i);
1309
1310         i = p_ptrn_lines;
1311         p_ptrn_lines = p_repl_lines;
1312         p_repl_lines = i;
1313
1314         free(tp_line);
1315         free(tp_len);
1316         free(tp_char);
1317
1318         return true;
1319 }
1320
1321 /*
1322  * Return the specified line position in the old file of the old context.
1323  */
1324 LINENUM
1325 pch_first(void)
1326 {
1327         return p_first;
1328 }
1329
1330 /*
1331  * Return the number of lines of old context.
1332  */
1333 LINENUM
1334 pch_ptrn_lines(void)
1335 {
1336         return p_ptrn_lines;
1337 }
1338
1339 /*
1340  * Return the probable line position in the new file of the first line.
1341  */
1342 LINENUM
1343 pch_newfirst(void)
1344 {
1345         return p_newfirst;
1346 }
1347
1348 /*
1349  * Return the number of lines in the replacement text including context.
1350  */
1351 LINENUM
1352 pch_repl_lines(void)
1353 {
1354         return p_repl_lines;
1355 }
1356
1357 /*
1358  * Return the number of lines in the whole hunk.
1359  */
1360 LINENUM
1361 pch_end(void)
1362 {
1363         return p_end;
1364 }
1365
1366 /*
1367  * Return the number of context lines before the first changed line.
1368  */
1369 LINENUM
1370 pch_context(void)
1371 {
1372         return p_context;
1373 }
1374
1375 /*
1376  * Return the length of a particular patch line.
1377  */
1378 short
1379 pch_line_len(LINENUM line)
1380 {
1381         return p_len[line];
1382 }
1383
1384 /*
1385  * Return the control character (+, -, *, !, etc) for a patch line.
1386  */
1387 char
1388 pch_char(LINENUM line)
1389 {
1390         return p_char[line];
1391 }
1392
1393 /*
1394  * Return a pointer to a particular patch line.
1395  */
1396 char *
1397 pfetch(LINENUM line)
1398 {
1399         return p_line[line];
1400 }
1401
1402 /*
1403  * Return where in the patch file this hunk began, for error messages.
1404  */
1405 LINENUM
1406 pch_hunk_beg(void)
1407 {
1408         return p_hunk_beg;
1409 }
1410
1411 /*
1412  * Apply an ed script by feeding ed itself.
1413  */
1414 void
1415 do_ed_script(void)
1416 {
1417         char    *t;
1418         long    beginning_of_this_line;
1419         FILE    *pipefp = NULL;
1420
1421         if (!skip_rest_of_patch) {
1422                 if (copy_file(filearg[0], TMPOUTNAME) < 0) {
1423                         unlink(TMPOUTNAME);
1424                         fatal("can't create temp file %s", TMPOUTNAME);
1425                 }
1426                 snprintf(buf, buf_size, "%s%s%s", _PATH_ED,
1427                     verbose ? " " : " -s ", TMPOUTNAME);
1428                 pipefp = popen(buf, "w");
1429         }
1430         for (;;) {
1431                 beginning_of_this_line = ftell(pfp);
1432                 if (pgets(true) == 0) {
1433                         next_intuit_at(beginning_of_this_line, p_input_line);
1434                         break;
1435                 }
1436                 p_input_line++;
1437                 for (t = buf; isdigit((unsigned char)*t) || *t == ','; t++)
1438                         ;
1439                 /* POSIX defines allowed commands as {a,c,d,i,s} */
1440                 if (isdigit((unsigned char)*buf) && (*t == 'a' || *t == 'c' ||
1441                     *t == 'd' || *t == 'i' || *t == 's')) {
1442                         if (pipefp != NULL)
1443                                 fputs(buf, pipefp);
1444                         if (*t != 'd') {
1445                                 while (pgets(true)) {
1446                                         p_input_line++;
1447                                         if (pipefp != NULL)
1448                                                 fputs(buf, pipefp);
1449                                         if (strEQ(buf, ".\n"))
1450                                                 break;
1451                                 }
1452                         }
1453                 } else {
1454                         next_intuit_at(beginning_of_this_line, p_input_line);
1455                         break;
1456                 }
1457         }
1458         if (pipefp == NULL)
1459                 return;
1460         fprintf(pipefp, "w\n");
1461         fprintf(pipefp, "q\n");
1462         fflush(pipefp);
1463         pclose(pipefp);
1464         ignore_signals();
1465         if (!check_only) {
1466                 if (move_file(TMPOUTNAME, outname) < 0) {
1467                         toutkeep = true;
1468                         chmod(TMPOUTNAME, filemode);
1469                 } else
1470                         chmod(outname, filemode);
1471         }
1472         set_signals(1);
1473 }
1474
1475 /*
1476  * Choose the name of the file to be patched based on POSIX rules.
1477  * NOTE: the POSIX rules are amazingly stupid and we only follow them
1478  *       if the user specified --posix or set POSIXLY_CORRECT.
1479  */
1480 static char *
1481 posix_name(const struct file_name *names, bool assume_exists)
1482 {
1483         char *path = NULL;
1484         int i;
1485
1486         /*
1487          * POSIX states that the filename will be chosen from one
1488          * of the old, new and index names (in that order) if
1489          * the file exists relative to CWD after -p stripping.
1490          */
1491         for (i = 0; i < MAX_FILE; i++) {
1492                 if (names[i].path != NULL && names[i].exists) {
1493                         path = names[i].path;
1494                         break;
1495                 }
1496         }
1497         if (path == NULL && !assume_exists) {
1498                 /*
1499                  * No files found, look for something we can checkout from
1500                  * RCS/SCCS dirs.  Same order as above.
1501                  */
1502                 for (i = 0; i < MAX_FILE; i++) {
1503                         if (names[i].path != NULL &&
1504                             (path = checked_in(names[i].path)) != NULL)
1505                                 break;
1506                 }
1507                 /*
1508                  * Still no match?  Check to see if the diff could be creating
1509                  * a new file.
1510                  */
1511                 if (path == NULL && ok_to_create_file &&
1512                     names[NEW_FILE].path != NULL)
1513                         path = names[NEW_FILE].path;
1514         }
1515
1516         return path ? savestr(path) : NULL;
1517 }
1518
1519 static char *
1520 compare_names(const struct file_name *names, bool assume_exists, int phase)
1521 {
1522         size_t min_components, min_baselen, min_len, tmp;
1523         char *best = NULL;
1524         char *path;
1525         int i;
1526
1527         /*
1528          * The "best" name is the one with the fewest number of path
1529          * components, the shortest basename length, and the shortest
1530          * overall length (in that order).  We only use the Index: file
1531          * if neither of the old or new files could be intuited from
1532          * the diff header.
1533          */
1534         min_components = min_baselen = min_len = SIZE_MAX;
1535         for (i = INDEX_FILE; i >= OLD_FILE; i--) {
1536                 path = names[i].path;
1537                 if (path == NULL ||
1538                     (phase == 1 && !names[i].exists && !assume_exists) ||
1539                     (phase == 2 && checked_in(path) == NULL))
1540                         continue;
1541                 if ((tmp = num_components(path)) > min_components)
1542                         continue;
1543                 if (tmp < min_components) {
1544                         min_components = tmp;
1545                         best = path;
1546                 }
1547                 if ((tmp = strlen(basename(path))) > min_baselen)
1548                         continue;
1549                 if (tmp < min_baselen) {
1550                         min_baselen = tmp;
1551                         best = path;
1552                 }
1553                 if ((tmp = strlen(path)) > min_len)
1554                         continue;
1555                 min_len = tmp;
1556                 best = path;
1557         }
1558         return best;
1559 }
1560
1561 /*
1562  * Choose the name of the file to be patched based the "best" one
1563  * available.
1564  */
1565 static char *
1566 best_name(const struct file_name *names, bool assume_exists)
1567 {
1568         char *best;
1569
1570         best = compare_names(names, assume_exists, 1);
1571         if (best == NULL) {
1572                 best = compare_names(names, assume_exists, 2);
1573                 /*
1574                  * Still no match?  Check to see if the diff could be creating
1575                  * a new file.
1576                  */
1577                 if (best == NULL && ok_to_create_file &&
1578                     names[NEW_FILE].path != NULL)
1579                         best = names[NEW_FILE].path;
1580         }
1581
1582         return best ? savestr(best) : NULL;
1583 }
1584
1585 static size_t
1586 num_components(const char *path)
1587 {
1588         size_t n;
1589         const char *cp;
1590
1591         for (n = 0, cp = path; (cp = strchr(cp, '/')) != NULL; n++, cp++) {
1592                 while (*cp == '/')
1593                         cp++;           /* skip consecutive slashes */
1594         }
1595         return n;
1596 }