2 * $OpenBSD: patch.c,v 1.43 2004/11/19 20:08:11 otto Exp $
3 * $DragonFly: src/usr.bin/patch/patch.c,v 1.6 2006/04/18 22:11:35 joerg Exp $
7 * patch - a program to apply diffs to original files
9 * Copyright 1986, Larry Wall
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following condition is met:
13 * 1. Redistributions of source code must retain the above copyright notice,
14 * this condition and the following disclaimer.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * -C option added in 1998, original code by Marc Espie, based on FreeBSD
32 #include <sys/types.h>
47 #include "backupfile.h"
48 #include "pathnames.h"
52 char buf[MAXLINELEN]; /* general purpose buffer */
53 size_t buf_len = sizeof(buf);
55 bool using_plan_a = true; /* try to keep everything in memory */
56 bool out_of_mem = false; /* ran out of memory in plan a */
60 char *filearg[MAXFILEC];
61 bool ok_to_create_file = false;
63 char *origprae = NULL;
68 bool toutkeep = false;
69 bool trejkeep = false;
70 bool warn_on_invalid_line;
71 bool last_line_missing_eol;
81 bool noreverse = false;
82 bool skip_rest_of_patch = false;
84 bool canonicalize = false;
85 bool check_only = false;
87 char *revision = NULL; /* prerequisite revision, if any */
88 LINENUM input_lines = 0; /* how long is input file in lines */
89 int posix = 0; /* strict POSIX mode? */
91 static void reinitialize_almost_everything(void);
92 static void get_some_switches(void);
93 static LINENUM locate_hunk(LINENUM);
94 static void abort_context_hunk(void);
95 static void rej_line(int, LINENUM);
96 static void abort_hunk(void);
97 static void apply_hunk(LINENUM);
98 static void init_output(const char *);
99 static void init_reject(const char *);
100 static void copy_till(LINENUM, bool);
101 static void spew_output(void);
102 static void dump_line(LINENUM, bool);
103 static bool patch_match(LINENUM, LINENUM, LINENUM);
104 static bool similar(const char *, const char *, int);
105 static void usage(void);
107 /* true if -E was specified on command line. */
108 static bool remove_empty_files = false;
110 /* true if -R was specified on command line. */
111 static bool reverse_flag_specified = false;
113 /* buffer holding the name of the rejected patch file. */
114 static char rejname[NAME_MAX + 1];
116 /* buffer for stderr */
117 static char serrbuf[BUFSIZ];
119 /* how many input lines have been irretractibly output */
120 static LINENUM last_frozen_line = 0;
122 static int Argc; /* guess */
124 static int Argc_last; /* for restarting plan_b */
125 static char **Argv_last;
127 static FILE *ofp = NULL; /* output file pointer */
128 static FILE *rejfp = NULL; /* reject file pointer */
130 static int filec = 0; /* how many file arguments? */
131 static LINENUM last_offset = 0;
132 static LINENUM maxfuzz = 2;
134 /* patch using ifdef, ifndef, etc. */
135 static bool do_defines = false;
137 static char if_defined[128];
139 static char not_defined[128];
141 static const char else_defined[] = "#else\n";
143 static char end_defined[128];
146 /* Apply a set of diffs as appropriate. */
149 main(int argc, char *argv[])
151 int error = 0, hunk, failed, i, fd;
152 LINENUM where = 0, newwhere, fuzz, mymaxfuzz;
156 setbuf(stderr, serrbuf);
157 for (i = 0; i < MAXFILEC; i++)
160 /* Cons up the names of the temporary files. */
161 if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
163 for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
166 if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
167 fatal("cannot allocate memory");
168 if ((fd = mkstemp(TMPOUTNAME)) < 0)
169 pfatal("can't create %s", TMPOUTNAME);
172 if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
173 fatal("cannot allocate memory");
174 if ((fd = mkstemp(TMPINNAME)) < 0)
175 pfatal("can't create %s", TMPINNAME);
178 if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
179 fatal("cannot allocate memory");
180 if ((fd = mkstemp(TMPREJNAME)) < 0)
181 pfatal("can't create %s", TMPREJNAME);
184 if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
185 fatal("cannot allocate memory");
186 if ((fd = mkstemp(TMPPATNAME)) < 0)
187 pfatal("can't create %s", TMPPATNAME);
190 v = getenv("SIMPLE_BACKUP_SUFFIX");
192 simple_backup_suffix = v;
194 simple_backup_suffix = ORIGEXT;
201 if (backup_type == none) {
202 if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
203 v = getenv("VERSION_CONTROL");
204 if (v != NULL || !posix)
205 backup_type = get_version(v); /* OK to pass NULL. */
208 /* make sure we clean up /tmp in case of disaster */
211 for (open_patch_file(filearg[1]); there_is_another_patch();
212 reinitialize_almost_everything()) {
213 /* for each patch in patch file */
215 warn_on_invalid_line = true;
218 outname = savestr(filearg[0]);
220 /* for ed script just up and do it and exit */
221 if (diff_type == ED_DIFF) {
225 /* initialize the patched file */
226 if (!skip_rest_of_patch)
227 init_output(TMPOUTNAME);
229 /* initialize reject file */
230 init_reject(TMPREJNAME);
232 /* find out where all the lines are */
233 if (!skip_rest_of_patch)
234 scan_input(filearg[0]);
236 /* from here on, open no standard i/o files, because malloc */
237 /* might misfire and we can't catch it easily */
239 /* apply each hunk of patch */
243 while (another_hunk()) {
246 mymaxfuzz = pch_context();
247 if (maxfuzz < mymaxfuzz)
249 if (!skip_rest_of_patch) {
251 where = locate_hunk(fuzz);
252 if (hunk == 1 && where == 0 && !force) {
253 /* dwim for reversed patch? */
256 say("Not enough memory to try swapped hunk! Assuming unswapped.\n");
261 where = locate_hunk(fuzz);
263 /* didn't find it swapped */
265 /* put it back to normal */
266 fatal("lost hunk on alloc error!\n");
268 } else if (noreverse) {
270 /* put it back to normal */
271 fatal("lost hunk on alloc error!\n");
273 say("Ignoring previously applied (or reversed) patch.\n");
274 skip_rest_of_patch = true;
277 say("%seversed (or previously applied) patch detected! %s -R.",
278 reverse ? "R" : "Unr",
279 reverse ? "Assuming" : "Ignoring");
281 ask("%seversed (or previously applied) patch detected! %s -R? [y] ",
282 reverse ? "R" : "Unr",
283 reverse ? "Assume" : "Ignore");
285 ask("Apply anyway? [n] ");
287 skip_rest_of_patch = true;
291 /* put it back to normal */
292 fatal("lost hunk on alloc error!\n");
296 } while (!skip_rest_of_patch && where == 0 &&
297 ++fuzz <= mymaxfuzz);
299 if (skip_rest_of_patch) { /* just got decided */
304 newwhere = pch_newfirst() + last_offset;
305 if (skip_rest_of_patch) {
309 say("Hunk #%d ignored at %ld.\n",
311 } else if (where == 0) {
315 say("Hunk #%d failed at %ld.\n",
320 say("Hunk #%d succeeded at %ld",
323 say(" with fuzz %ld", fuzz);
325 say(" (offset %ld line%s)",
327 last_offset == 1L ? "" : "s");
333 if (out_of_mem && using_plan_a) {
336 say("\n\nRan out of memory using Plan A--trying again...\n\n");
346 fatal("Internal error: hunk should not be 0\n");
348 /* finish spewing out the new file */
349 if (!skip_rest_of_patch)
352 /* and put the output where desired */
354 if (!skip_rest_of_patch) {
356 char *realout = outname;
359 if (move_file(TMPOUTNAME, outname) < 0) {
361 realout = TMPOUTNAME;
362 chmod(TMPOUTNAME, filemode);
364 chmod(outname, filemode);
366 if (remove_empty_files &&
367 stat(realout, &statbuf) == 0 &&
368 statbuf.st_size == 0) {
370 say("Removing %s (empty after patching).\n",
380 if (*rejname == '\0') {
381 if (strlcpy(rejname, outname,
382 sizeof(rejname)) >= sizeof(rejname))
383 fatal("filename %s is too long\n", outname);
384 if (strlcat(rejname, REJEXT,
385 sizeof(rejname)) >= sizeof(rejname))
386 fatal("filename %s is too long\n", outname);
388 if (skip_rest_of_patch) {
389 say("%d out of %d hunks ignored--saving rejects to %s\n",
390 failed, hunk, rejname);
392 say("%d out of %d hunks failed--saving rejects to %s\n",
393 failed, hunk, rejname);
395 if (!check_only && move_file(TMPREJNAME, rejname) < 0)
404 /* Prepare to find the next patch to do in the patch file. */
407 reinitialize_almost_everything(void)
413 last_frozen_line = 0;
430 reverse = reverse_flag_specified;
431 skip_rest_of_patch = false;
436 /* Process switches and filenames. */
439 get_some_switches(void)
441 const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
442 static struct option longopts[] = {
443 {"backup", no_argument, 0, 'b'},
444 {"batch", no_argument, 0, 't'},
445 {"check", no_argument, 0, 'C'},
446 {"context", no_argument, 0, 'c'},
447 {"debug", required_argument, 0, 'x'},
448 {"directory", required_argument, 0, 'd'},
449 {"ed", no_argument, 0, 'e'},
450 {"force", no_argument, 0, 'f'},
451 {"forward", no_argument, 0, 'N'},
452 {"fuzz", required_argument, 0, 'F'},
453 {"ifdef", required_argument, 0, 'D'},
454 {"input", required_argument, 0, 'i'},
455 {"ignore-whitespace", no_argument, 0, 'l'},
456 {"normal", no_argument, 0, 'n'},
457 {"output", required_argument, 0, 'o'},
458 {"prefix", required_argument, 0, 'B'},
459 {"quiet", no_argument, 0, 's'},
460 {"reject-file", required_argument, 0, 'r'},
461 {"remove-empty-files", no_argument, 0, 'E'},
462 {"reverse", no_argument, 0, 'R'},
463 {"silent", no_argument, 0, 's'},
464 {"strip", required_argument, 0, 'p'},
465 {"suffix", required_argument, 0, 'z'},
466 {"unified", no_argument, 0, 'u'},
467 {"version", no_argument, 0, 'v'},
468 {"version-control", required_argument, 0, 'V'},
469 {"posix", no_argument, &posix, 1},
479 optreset = optind = 1;
480 while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
483 if (backup_type == none)
484 backup_type = numbered_existing;
488 say("Warning, the ``-b suffix'' option has been"
489 " obsoleted by the -z option.\n");
492 /* must directly follow 'b' case for backwards compat */
493 simple_backup_suffix = savestr(optarg);
496 origprae = savestr(optarg);
499 diff_type = CONTEXT_DIFF;
505 if (chdir(optarg) < 0)
506 pfatal("can't cd to %s", optarg);
510 if (!isalpha((unsigned char)*optarg) && *optarg != '_')
511 fatal("argument to -D is not an identifier\n");
512 snprintf(if_defined, sizeof if_defined,
513 "#ifdef %s\n", optarg);
514 snprintf(not_defined, sizeof not_defined,
515 "#ifndef %s\n", optarg);
516 snprintf(end_defined, sizeof end_defined,
517 "#endif /* %s */\n", optarg);
523 remove_empty_files = true;
529 maxfuzz = atoi(optarg);
532 if (++filec == MAXFILEC)
533 fatal("too many file arguments\n");
534 filearg[filec] = savestr(optarg);
540 diff_type = NORMAL_DIFF;
546 outname = savestr(optarg);
549 strippath = atoi(optarg);
552 if (strlcpy(rejname, optarg,
553 sizeof(rejname)) >= sizeof(rejname))
554 fatal("argument for -r is too long\n");
558 reverse_flag_specified = true;
567 diff_type = UNI_DIFF;
573 backup_type = get_version(optarg);
577 debug = atoi(optarg);
590 filearg[0] = savestr(*Argv++);
593 if (++filec == MAXFILEC)
594 fatal("too many file arguments\n");
595 filearg[filec] = savestr(*Argv++);
600 if (getenv("POSIXLY_CORRECT") != NULL)
608 "usage: patch [-bcCeEflnNRstuv] [-B backup-prefix] [-d directory] [-D symbol]\n"
609 " [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
610 " [-r rej-name] [-V {numbered,existing,simple}] [-z backup-ext]\n"
611 " [origfile [patchfile]]\n");
612 my_exit(EXIT_SUCCESS);
616 * Attempt to find the right place to apply this hunk of patch.
619 locate_hunk(LINENUM fuzz)
621 LINENUM first_guess = pch_first() + last_offset;
623 LINENUM pat_lines = pch_ptrn_lines();
624 LINENUM max_pos_offset = input_lines - first_guess - pat_lines + 1;
625 LINENUM max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
627 if (pat_lines == 0) { /* null range matches always */
628 if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
629 || diff_type == NEW_CONTEXT_DIFF
630 || diff_type == UNI_DIFF)) {
631 say("Empty context always matches.\n");
633 if (diff_type == CONTEXT_DIFF
634 || diff_type == NEW_CONTEXT_DIFF
635 || diff_type == UNI_DIFF) {
637 return (input_lines == 0 ? first_guess : 0);
639 return (first_guess);
641 if (max_neg_offset >= first_guess) /* do not try lines < 0 */
642 max_neg_offset = first_guess - 1;
643 if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
645 for (offset = 1; ; offset++) {
646 bool check_after = (offset <= max_pos_offset);
647 bool check_before = (offset <= max_neg_offset);
649 if (check_after && patch_match(first_guess, offset, fuzz)) {
652 say("Offset changing from %ld to %ld\n",
653 last_offset, offset);
655 last_offset = offset;
656 return first_guess + offset;
657 } else if (check_before && patch_match(first_guess, -offset, fuzz)) {
660 say("Offset changing from %ld to %ld\n",
661 last_offset, -offset);
663 last_offset = -offset;
664 return first_guess - offset;
665 } else if (!check_before && !check_after)
670 /* We did not find the pattern, dump out the hunk so they can handle it. */
673 abort_context_hunk(void)
676 const LINENUM pat_end = pch_end();
678 * add in last_offset to guess the same as the previous successful
681 const LINENUM oldfirst = pch_first() + last_offset;
682 const LINENUM newfirst = pch_newfirst() + last_offset;
683 const LINENUM oldlast = oldfirst + pch_ptrn_lines() - 1;
684 const LINENUM newlast = newfirst + pch_repl_lines() - 1;
685 const char *stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
686 const char *minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
688 fprintf(rejfp, "***************\n");
689 for (i = 0; i <= pat_end; i++) {
690 switch (pch_char(i)) {
692 if (oldlast < oldfirst)
693 fprintf(rejfp, "*** 0%s\n", stars);
694 else if (oldlast == oldfirst)
695 fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
697 fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
701 if (newlast < newfirst)
702 fprintf(rejfp, "--- 0%s\n", minuses);
703 else if (newlast == newfirst)
704 fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
706 fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
710 fprintf(rejfp, "%s", pfetch(i));
716 fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
719 fatal("fatal internal error in abort_context_hunk\n");
725 rej_line(int ch, LINENUM i)
728 const char *line = pfetch(i);
732 fprintf(rejfp, "%c%s", ch, line);
733 if (len == 0 || line[len-1] != '\n')
734 fprintf(rejfp, "\n\\ No newline at end of file\n");
742 const LINENUM pat_end = pch_end();
743 const LINENUM oldfirst = pch_first() + last_offset;
744 const LINENUM newfirst = pch_newfirst() + last_offset;
746 if (diff_type != UNI_DIFF) {
747 abort_context_hunk();
751 for (i = 0; i <= pat_end; i++) {
752 if (pch_char(i) == '=') {
758 fprintf(rejfp, "malformed hunk: no split found\n");
763 fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
764 pch_ptrn_lines() ? oldfirst : 0,
765 pch_ptrn_lines(), newfirst, pch_repl_lines());
766 while (i < split || j <= pat_end) {
767 ch1 = i < split ? pch_char(i) : -1;
768 ch2 = j <= pat_end ? pch_char(j) : -1;
772 } else if (ch1 == ' ' && ch2 == ' ') {
776 } else if (ch1 == '!' && ch2 == '!') {
777 while (i < split && ch1 == '!') {
780 ch1 = i < split ? pch_char(i) : -1;
782 while (j <= pat_end && ch2 == '!') {
785 ch2 = j <= pat_end ? pch_char(j) : -1;
787 } else if (ch1 == '*') {
789 } else if (ch2 == '+' || ch2 == ' ') {
793 fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
802 /* We found where to apply it (we hope), so do it. */
805 apply_hunk(LINENUM where)
808 const LINENUM lastline = pch_ptrn_lines();
809 LINENUM new = lastline + 1;
814 int def_state = OUTSIDE;
815 const LINENUM pat_end = pch_end();
818 while (pch_char(new) == '=' || pch_char(new) == '\n')
821 while (old <= lastline) {
822 if (pch_char(old) == '-') {
823 copy_till(where + old - 1, false);
825 if (def_state == OUTSIDE) {
826 fputs(not_defined, ofp);
827 def_state = IN_IFNDEF;
828 } else if (def_state == IN_IFDEF) {
829 fputs(else_defined, ofp);
832 fputs(pfetch(old), ofp);
836 } else if (new > pat_end) {
838 } else if (pch_char(new) == '+') {
839 copy_till(where + old - 1, false);
841 if (def_state == IN_IFNDEF) {
842 fputs(else_defined, ofp);
844 } else if (def_state == OUTSIDE) {
845 fputs(if_defined, ofp);
846 def_state = IN_IFDEF;
849 fputs(pfetch(new), ofp);
851 } else if (pch_char(new) != pch_char(old)) {
852 say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
853 pch_hunk_beg() + old,
854 pch_hunk_beg() + new);
856 say("oldchar = '%c', newchar = '%c'\n",
857 pch_char(old), pch_char(new));
860 } else if (pch_char(new) == '!') {
861 copy_till(where + old - 1, false);
863 fputs(not_defined, ofp);
864 def_state = IN_IFNDEF;
866 while (pch_char(old) == '!') {
868 fputs(pfetch(old), ofp);
874 fputs(else_defined, ofp);
877 while (pch_char(new) == '!') {
878 fputs(pfetch(new), ofp);
882 if (pch_char(new) != ' ')
883 fatal("Internal error: expected ' '\n");
886 if (do_defines && def_state != OUTSIDE) {
887 fputs(end_defined, ofp);
892 if (new <= pat_end && pch_char(new) == '+') {
893 copy_till(where + old - 1, false);
895 if (def_state == OUTSIDE) {
896 fputs(if_defined, ofp);
897 def_state = IN_IFDEF;
898 } else if (def_state == IN_IFNDEF) {
899 fputs(else_defined, ofp);
903 while (new <= pat_end && pch_char(new) == '+') {
904 fputs(pfetch(new), ofp);
908 if (do_defines && def_state != OUTSIDE) {
909 fputs(end_defined, ofp);
917 init_output(const char *name)
919 ofp = fopen(name, "w");
921 pfatal("can't create %s", name);
925 * Open a file to put hunks we can't locate.
928 init_reject(const char *name)
930 rejfp = fopen(name, "w");
932 pfatal("can't create %s", name);
936 * Copy input file to output, up to wherever hunk is to be applied.
937 * If endoffile is true, treat the last line specially since it may
941 copy_till(LINENUM lastline, bool endoffile)
943 if (last_frozen_line > lastline)
944 fatal("misordered hunks! output would be garbled\n");
945 while (last_frozen_line < lastline) {
946 if (++last_frozen_line == lastline && endoffile)
947 dump_line(last_frozen_line, !last_line_missing_eol);
949 dump_line(last_frozen_line, true);
954 * Finish copying the input file to the output file.
961 say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
964 copy_till(input_lines, true); /* dump remainder of file */
970 * Copy one line from input to output.
973 dump_line(LINENUM line, bool write_newline)
980 /* Note: string is not NUL terminated. */
981 for (; *s != '\n'; s++)
988 * Does the patch pattern match at line base+offset?
991 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
993 LINENUM pline = 1 + fuzz;
995 LINENUM pat_lines = pch_ptrn_lines() - fuzz;
996 const char *ilineptr;
997 const char *plineptr;
1000 for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1001 ilineptr = ifetch(iline, offset >= 0);
1002 if (ilineptr == NULL)
1004 plineptr = pfetch(pline);
1005 plinelen = pch_line_len(pline);
1007 if (!similar(ilineptr, plineptr, plinelen))
1009 } else if (strnNE(ilineptr, plineptr, plinelen))
1011 if (iline == input_lines) {
1013 * We are looking at the last line of the file.
1014 * If the file has no eol, the patch line should
1015 * not have one either and vice-versa. Note that
1018 if (last_line_missing_eol) {
1019 if (plineptr[plinelen - 1] == '\n')
1022 if (plineptr[plinelen - 1] != '\n')
1031 * Do two lines match with canonicalized white space?
1034 similar(const char *a, const char *b, int len)
1037 if (isspace((unsigned char)*b)) { /* whitespace (or \n) to match? */
1038 if (!isspace((unsigned char)*a)) /* no corresponding whitespace? */
1040 while (len && isspace((unsigned char)*b) && *b != '\n')
1041 b++, len--; /* skip pattern whitespace */
1042 while (isspace((unsigned char)*a) && *a != '\n')
1043 a++; /* skip target whitespace */
1044 if (*a == '\n' || *b == '\n')
1045 return (*a == *b); /* should end in sync */
1046 } else if (*a++ != *b++) /* match non-whitespace chars */
1049 len--; /* probably not necessary */
1051 return true; /* actually, this is not reached */
1052 /* since there is always a \n */