/*
  retest.c - TRE regression test program

  This software is released under a BSD-style license.
  See the file LICENSE for details and copyright.

*/

/*
   This is just a simple test application containing various hands-written
   tests for regression testing TRE.  I've tried to surround TRE specific
   tests inside ifdefs, so this can be used to test any POSIX compatible
   regexp implementation.
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif /* HAVE_CONFIG_H */

#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <sys/types.h>
#include <locale.h>
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif /* HAVE_MALLOC_H */
#include <regex.h>

#ifdef TRE_VERSION
#define HAVE_REGNEXEC 1
#define HAVE_REGNCOMP 1
#include "xmalloc.h"
#else /* !TRE_VERSION */
#define xmalloc malloc
#define xfree free
#endif /* !TRE_VERSION */
#include "tre-internal.h"

#ifdef WRETEST
#include <wchar.h>
#define CHAR_T wchar_t
#define L(x) (L ## x)

#define MAXSTRSIZE 1024
static wchar_t wstr[MAXSTRSIZE];
static wchar_t wregex[MAXSTRSIZE];
static int woffs[MAXSTRSIZE];

#define tre_regexec tre_regwexec
#define tre_regnexec tre_regwnexec
#define tre_regcomp tre_regwcomp
#define tre_regncomp tre_regwncomp

/* Iterate mbrtowc over the multi-byte sequence STR of length LEN,
   store the result in BUF and memoize the successive byte offsets
   in OFF.  */

static int
mbntowc (wchar_t *buf, const char *str, size_t len, int *off)
{
  int n, wlen;
#ifdef HAVE_MBSTATE_T
  mbstate_t cst;
  memset(&cst, 0, sizeof(cst));
#endif

  if (len >= MAXSTRSIZE)
    {
      fprintf(stderr, "Increase MAXSTRSIZE to %ld or more and recompile!\n",
	      (long)len + 1);
      exit(EXIT_FAILURE);
    }

  if (off)
    {
      memset(off + 1, -1, len * sizeof(int));
      *off = 0;
    }

  wlen = 0;
  while (len > 0)
    {
      n = tre_mbrtowc(buf ? buf++ : NULL, str, len, &cst);
      if (n < 0)
	return n;
      if (n == 0)
	n = 1;
      str += n;
      len -= n;
      wlen += 1;
      if (off)
	*(off += n) = wlen;
    }

  return(wlen);
}

#else /* !WRETEST */
#define CHAR_T char
#define L(x) (x)
#endif /* !WRETEST */

static int valid_reobj = 0;
static regex_t reobj;
static regmatch_t pmatch_global[32];
static const CHAR_T *regex_pattern;
static int cflags_global;
static int use_regnexec = 0;
static int use_regncomp = 0;
static int avoid_eflags = 0;

static int comp_tests = 0;
static int exec_tests = 0;
static int comp_errors = 0;
static int exec_errors = 0;

#ifndef REG_OK
#define REG_OK 0
#endif /* REG_OK */

#define END -2

static void
test_status(char c)
{
  static int k = 0;
  printf("%c", c);
  if (++k % 79 == 0)
    printf("\n");
  fflush(stdout);
}


static int
wrap_regexec(const CHAR_T *data, size_t len,
	     size_t pmatch_len, regmatch_t *pmatch, int eflags)
{
  CHAR_T *buf = NULL;
  int result;

  if (len == 0 && use_regnexec)
    {
      /* Zero length string and using tre_regnexec(), the pointer we give
	 should not be dereferenced at all. */
      buf = NULL;
    }
  else
    {
      /* Copy the data to a separate buffer to make a better test for
	 tre_regexec() and tre_regnexec(). */
      buf = xmalloc((len + !use_regnexec) * sizeof(CHAR_T));
      if (!buf)
	return REG_ESPACE;
      memcpy(buf, data, len * sizeof(CHAR_T));
      test_status('#');
    }

#ifdef HAVE_REGNEXEC
  if (use_regnexec)
    {
      if (len == 0)
	result = tre_regnexec(&reobj, NULL, len, pmatch_len, pmatch, eflags);
      else
	result = tre_regnexec(&reobj, buf, len, pmatch_len, pmatch, eflags);
    }
  else
#endif /* HAVE_REGNEXEC */
    {
      buf[len] = L('\0');
      result = tre_regexec(&reobj, buf, pmatch_len, pmatch, eflags);
    }

  xfree(buf);
  return result;
}

static int
wrap_regcomp(regex_t *preg, const CHAR_T *data, size_t len, int cflags)
{
#ifdef HAVE_REGNCOMP
  if (use_regncomp)
    return tre_regncomp(preg, data, len, cflags);
  else
    return tre_regcomp(preg, data, cflags);
#else /* !HAVE_REGNCOMP */
  fprintf(stderr, "%s\n", data);
  return tre_regcomp(preg, data, cflags);
#endif /* !HAVE_REGNCOMP */
}

static int
execute(const CHAR_T *data, int len, size_t pmatch_len, regmatch_t *pmatch,
	int eflags)
{
#ifdef MALLOC_DEBUGGING
  int i = 0;
  int ret;

  while (1)
    {
      xmalloc_configure(i);
      comp_tests++;
      ret = wrap_regexec(data, len, pmatch_len, pmatch, eflags);
      if (ret != REG_ESPACE)
	{
	  break;
	}
#ifdef REGEX_DEBUG
      xmalloc_dump_leaks();
#endif /* REGEX_DEBUG */
      i++;
    }
  return ret;
#else /* !MALLOC_DEBUGGING */
  return wrap_regexec(data, len, pmatch_len, pmatch, eflags);
#endif /* !MALLOC_DEBUGGING */
}

static int
check(va_list ap, int ret, const CHAR_T *str,
      size_t pmatch_len, regmatch_t *pmatch, int eflags)
{
  int fail = 0;

  if (ret != va_arg(ap, int))
    {
#ifndef WRETEST
      printf("Exec error, regex: \"%s\", cflags %d, "
	     "string: \"%s\", eflags %d\n", regex_pattern, cflags_global,
	     str, eflags);
#else /* WRETEST */
      printf("Exec error, regex: \"%ls\", cflags %d, "
	     "string: \"%ls\", eflags %d\n", regex_pattern, cflags_global,
	     str, eflags);
#endif /* WRETEST */
      printf("	got %smatch (tre_regexec returned %d)\n", ret ? "no " : "", ret);
      return 1;
    }

  if (ret == 0)
    {
      unsigned int i;

      for (i = 0; i < pmatch_len; i++)
	{
	  int rm_so, rm_eo;
	  rm_so = va_arg(ap, int);
	  if (rm_so == END)
	    break;
	  rm_eo = va_arg(ap, int);
#ifdef WRETEST
	  if (rm_so >= 0)
	    {
	      int n = rm_so;

	      if ((rm_so = woffs[rm_so]) < 0 ||
		  (n = rm_eo, rm_eo = woffs[rm_eo]) < 0)
		{
		  printf("Invalid or incomplete multi-byte sequence "
			 "in string %ls before byte offset %d\n", str, n);
		  return 1;
		}
	    }
#endif /* WRETEST */
	  if (pmatch[i].rm_so != rm_so
	      || pmatch[i].rm_eo != rm_eo)
	    {
#ifndef WRETEST
	      printf("Exec error, regex: \"%s\", string: \"%s\"\n",
		     regex_pattern, str);
	      printf("	group %d: expected (%d, %d) \"%.*s\", "
		     "got (%d, %d) \"%.*s\"\n",
#else /* WRETEST */
	      printf("Exec error, regex: \"%ls\", string: \"%ls\"\n",
		     regex_pattern, str);
	      printf("	group %d: expected (%d, %d) \"%.*ls\", "
		     "got (%d, %d) \"%.*ls\"\n",
#endif /* WRETEST */
		     i, rm_so, rm_eo, rm_eo - rm_so, str + rm_so,
		     (int)pmatch[i].rm_so, (int)pmatch[i].rm_eo,
		     (int)(pmatch[i].rm_eo - pmatch[i].rm_so),
		     str + pmatch[i].rm_so);
	      fail = 1;
	    }
	}

      if (!(cflags_global & REG_NOSUB) && reobj.re_nsub != i - 1
	  && reobj.re_nsub <= pmatch_len && pmatch)
	{
#ifndef WRETEST
	  printf("Comp error, regex: \"%s\"\n", regex_pattern);
#else /* WRETEST */
	  printf("Comp error, regex: \"%ls\"\n", regex_pattern);
#endif /* WRETEST */
	  printf("  re_nsub is %d, should be %d\n", (int)reobj.re_nsub, i - 1);
	  fail = 1;
	}


      for (; i < pmatch_len; i++)
	if (pmatch[i].rm_so != -1 || pmatch[i].rm_eo != -1)
	  {
	    if (!fail)
#ifndef WRETEST
	      printf("Exec error, regex: \"%s\", string: \"%s\"\n",
		     regex_pattern, str);
#else /* WRETEST */
	      printf("Exec error, regex: \"%ls\", string: \"%ls\"\n",
		     regex_pattern, str);
#endif /* WRETEST */
	    printf("  group %d: expected (-1, -1), got (%d, %d)\n",
		   i, (int)pmatch[i].rm_so, (int)pmatch[i].rm_eo);
	    fail = 1;
	  }
    }

  return fail;
}


static void
test_nexec(const char *data, size_t len, int eflags, ...)
{
  int m;
  int fail = 0;
  int extra_flags[] = {0, REG_BACKTRACKING_MATCHER, REG_APPROX_MATCHER};
  size_t i;
  va_list ap;

  if (!valid_reobj)
    {
      exec_errors++;
      return;
    }

#ifdef WRETEST
      {
	int wlen = mbntowc(wstr, data, len, woffs);
	if (wlen < 0)
	  {
	    exec_errors++;
	    printf("Invalid or incomplete multi-byte sequence in %s\n", data);
	    return;
	  }
	wstr[wlen] = L'\0';
	len = wlen;
      }
#define data wstr
#endif /* WRETEST */

  use_regnexec = 1;

  for (i = 0; i < elementsof(extra_flags); i++)
    {
      int final_flags = eflags | extra_flags[i];

      if ((final_flags & REG_BACKTRACKING_MATCHER
	   && tre_have_approx(&reobj))
	  || (final_flags & REG_APPROX_MATCHER
	      && tre_have_backrefs(&reobj))
	  || (final_flags & avoid_eflags))
	continue;

      /* Test with a pmatch array. */
      exec_tests++;
      m = execute(data, len, elementsof(pmatch_global), pmatch_global,
		  final_flags);
      va_start(ap, eflags);
      fail |= check(ap, m, data, elementsof(pmatch_global), pmatch_global,
		    final_flags);
      va_end(ap);

      /* Same test with a NULL pmatch. */
      exec_tests++;
      m = execute(data, len, 0, NULL, final_flags);
      va_start(ap, eflags);
      fail |= check(ap, m, data, 0, NULL, final_flags);
      va_end(ap);
    }

#ifdef WRETEST
#undef data
#endif /* WRETEST */

  if (fail)
    exec_errors++;
}



static void
test_exec(const char *str, int eflags, ...)
{
  int m;
  int fail = 0;
  size_t len = strlen(str);
  int extra_flags[] = {0,
		       REG_BACKTRACKING_MATCHER,
		       REG_APPROX_MATCHER,
		       REG_BACKTRACKING_MATCHER | REG_APPROX_MATCHER};
  size_t i;
  va_list ap;

  if (!valid_reobj)
    {
      exec_errors++;
      return;
    }

#ifdef WRETEST
      {
	int wlen = mbntowc(wstr, str, len, woffs);
	if (wlen < 0)
	  {
	    exec_errors++;
	    printf("Invalid or incomplete multi-byte sequence in %s\n", str);
	    return;
	  }
	wstr[wlen] = L'\0';
	len = wlen;
      }
#define str wstr
#endif /* WRETEST */

  for (use_regnexec = 0; use_regnexec < 2; use_regnexec++)
    {
      for (i = 0; i < elementsof(extra_flags); i++)
	{
	  int final_flags = eflags | extra_flags[i];

	  if ((final_flags & REG_BACKTRACKING_MATCHER
	       && tre_have_approx(&reobj))
	      || (final_flags & REG_APPROX_MATCHER
		  && tre_have_backrefs(&reobj))
	      || (final_flags & avoid_eflags))
	    continue;

	  /* Test with a pmatch array. */
	  exec_tests++;
	  m = execute(str, len, elementsof(pmatch_global), pmatch_global,
		      final_flags);
	  va_start(ap, eflags);
	  fail |= check(ap, m, str, elementsof(pmatch_global), pmatch_global,
			final_flags);
	  va_end(ap);

	  /* Same test with a NULL pmatch. */
	  exec_tests++;
	  m = execute(str, len, 0, NULL, final_flags);
	  va_start(ap, eflags);
	  fail |= check(ap, m, str, 0, NULL, final_flags);
	  va_end(ap);
	}
    }

#ifdef WRETEST
#undef str
#endif /* WRETEST */

  if (fail)
    exec_errors++;
}


static void
test_comp(const char *re, int flags, int ret)
{
  int errcode = 0;
  int len = strlen(re);

  if (valid_reobj)
    {
      tre_regfree(&reobj);
      valid_reobj = 0;
    }

  comp_tests++;

#ifdef WRETEST
  {
    int wlen = mbntowc(wregex, re, len, NULL);

    if (wlen < 0)
      {
	comp_errors++;
	printf("Invalid or incomplete multi-byte sequence in %s\n", re);
	return;
      }
    wregex[wlen] = L'\0';
    len = wlen;
  }
#define re wregex
#endif /* WRETEST */
  regex_pattern = re;
  cflags_global = flags;

#ifdef MALLOC_DEBUGGING
  {
    static int j = 0;
    int i = 0;
    while (1)
      {
	xmalloc_configure(i);
	comp_tests++;
	if (j++ % 20 == 0)
	  test_status('.');
	errcode = wrap_regcomp(&reobj, re, len, flags);
	if (errcode != REG_ESPACE)
	  {
	    test_status('*');
	    break;
	  }
#ifdef REGEX_DEBUG
	xmalloc_dump_leaks();
#endif /* REGEX_DEBUG */
	i++;
      }
  }
#else /* !MALLOC_DEBUGGING */
  errcode = wrap_regcomp(&reobj, re, len, flags);
#endif /* !MALLOC_DEBUGGING */

#ifdef WRETEST
#undef re
#endif /* WRETEST */

  if (errcode != ret)
    {
#ifndef WRETEST
      printf("Comp error, regex: \"%s\"\n", regex_pattern);
#else /* WRETEST */
      printf("Comp error, regex: \"%ls\"\n", regex_pattern);
#endif /* WRETEST */
      printf("	expected return code %d, got %d.\n",
	     ret, errcode);
      comp_errors++;
    }

  if (errcode == 0)
    valid_reobj = 1;
}



/* To enable tests for known bugs, set this to 1. */
#define KNOWN_BUG 0

int
main(int argc, char **argv)
{

#ifdef WRETEST
  /* Need an 8-bit locale.  Or move the two tests with non-ascii
     characters to the localized internationalization tests.  */
  if (setlocale(LC_CTYPE, "en_US.ISO-8859-1") == NULL)
    fprintf(stderr, "Could not set locale en_US.ISO-8859-1.  Expect some\n"
		    "`Invalid or incomplete multi-byte sequence' errors.\n");
#endif /* WRETEST */
  /* Large number of macros in one regexp. */
  test_comp("[A-Z]\\d\\s?\\d[A-Z]{2}|[A-Z]\\d{2}\\s?\\d[A-Z]{2}|[A-Z]{2}\\d"
	    "\\s?\\d[A-Z]{2}|[A-Z]{2}\\d{2}\\s?\\d[A-Z]{2}|[A-Z]\\d[A-Z]\\s?"
	    "\\d[A-Z]{2}|[A-Z]{2}\\d[A-Z]\\s?\\d[A-Z]{2}|[A-Z]{3}\\s?\\d[A-Z]"
	    "{2}", REG_EXTENDED, 0);

  test_comp("a{11}(b{2}c){2}", REG_EXTENDED, 0);
  test_comp("a{2}{2}xb+xc*xd?x", REG_EXTENDED, 0);
  test_comp("^!packet [0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3} [0-9]+",
	    REG_EXTENDED, 0);
  test_comp("^!pfast [0-9]{1,15} ([0-9]{1,3}\\.){3}[0-9]{1,3}[0-9]{1,5}$",
	    REG_EXTENDED, 0);

#if KNOWN_BUG
  /* Should these match or not? */
  test_comp("(a)*-\\1b", REG_EXTENDED, 0);
  test_exec("aaa-b", 0, REG_NOMATCH);
  test_comp("((.*)\\1)+", REG_EXTENDED, 0);
  test_exec("xxxxxx", 0, REG_NOMATCH);
#endif

#ifdef TRE_APPROX
  /*
   * Approximate matching tests.
   *
   * The approximate matcher always searches for the best match, and returns
   * the leftmost and longest one if there are several best matches.
   */

  test_comp("(fou){# ~1}", REG_EXTENDED, 0);
  test_comp("(fuu){#}", REG_EXTENDED, 0);
  test_comp("(fuu){# ~}", REG_EXTENDED, 0);
  test_comp("(anaconda){ 1i + 1d < 1, #1}", REG_EXTENDED, 0);
  test_comp("(anaconda){ 1i + 1d < 1 #1 ~10 }", REG_EXTENDED, 0);
  test_comp("(anaconda){ #1, ~1, 1i + 1d < 1 }", REG_EXTENDED, 0);

  test_comp("(znacnda){ #1 ~3 1i + 1d < 1 }", REG_EXTENDED, 0);
  test_exec("molasses anaconda foo bar baz smith anderson ",
	    0, REG_NOMATCH);
  test_comp("(znacnda){ #1 ~3 1i + 1d < 2 }", REG_EXTENDED, 0);
  test_exec("molasses anaconda foo bar baz smith anderson ",
	    0, REG_OK, 9, 17, 9, 17, END);
  test_comp("(ananda){ 1i + 1d < 2 }", REG_EXTENDED, 0);
  test_exec("molasses anaconda foo bar baz smith anderson ",
	    0, REG_NOMATCH);

  test_comp("(fuu){ +3 -3 ~5}", REG_EXTENDED, 0);
  test_exec("anaconda foo bar baz smith anderson",
	    0, REG_OK, 9, 10, 9, 10, END);
  test_comp("(fuu){ +2 -2 ~5}", REG_EXTENDED, 0);
  test_exec("anaconda foo bar baz smith anderson",
	    0, REG_OK, 9, 10, 9, 10, END);
  test_comp("(fuu){ +3 -3 ~}", REG_EXTENDED, 0);
  test_exec("anaconda foo bar baz smith anderson",
	    0, REG_OK, 9, 10, 9, 10, END);

  test_comp("(laurikari){ #3, 1i + 1d < 3 }", REG_EXTENDED, 0);

  /* No cost limit. */
  test_comp("(foobar){~}", REG_EXTENDED, 0);
  test_exec("xirefoabralfobarxie", 0, REG_OK, 11, 16, 11, 16, END);

  /* At most two errors. */
  test_comp("(foobar){~2}", REG_EXTENDED, 0);
  test_exec("xirefoabrzlfd", 0, REG_OK, 4, 9, 4, 9, END);
  test_exec("xirefoabzlfd", 0, REG_NOMATCH);

  /* At most two inserts or substitutions and max two errors total. */
  test_comp("(foobar){+2#2~2}", REG_EXTENDED, 0);
  test_exec("oobargoobaploowap", 0, REG_OK, 5, 11, 5, 11, END);

  /* Find best whole word match for "foobar". */
  test_comp("\\<(foobar){~}\\>", REG_EXTENDED, 0);
  test_exec("zfoobarz", 0, REG_OK, 0, 8, 0, 8, END);
  test_exec("boing zfoobarz goobar woop", 0, REG_OK, 15, 21, 15, 21, END);

  /* Match whole string, allow only 1 error. */
  test_comp("^(foobar){~1}$", REG_EXTENDED, 0);
  test_exec("foobar", 0, REG_OK, 0, 6, 0, 6, END);
  test_exec("xfoobar", 0, REG_OK, 0, 7, 0, 7, END);
  /*
    This currently fails.
  test_exec("foobarx", 0, REG_OK, 0, 7, 0, 7, END);
  */
  test_exec("fooxbar", 0, REG_OK, 0, 7, 0, 7, END);
  test_exec("foxbar", 0, REG_OK, 0, 6, 0, 6, END);
  test_exec("xoobar", 0, REG_OK, 0, 6, 0, 6, END);
  test_exec("foobax", 0, REG_OK, 0, 6, 0, 6, END);
  test_exec("oobar", 0, REG_OK, 0, 5, 0, 5, END);
  test_exec("fobar", 0, REG_OK, 0, 5, 0, 5, END);
  test_exec("fooba", 0, REG_OK, 0, 5, 0, 5, END);
  test_exec("xfoobarx", 0, REG_NOMATCH);
  test_exec("foobarxx", 0, REG_NOMATCH);
  test_exec("xxfoobar", 0, REG_NOMATCH);
  test_exec("xfoxbar", 0, REG_NOMATCH);
  test_exec("foxbarx", 0, REG_NOMATCH);

  /* At most one insert, two deletes, and three substitutions.
     Additionally, deletes cost two and substitutes one, and total
     cost must be less than 4. */
  test_comp("(foobar){+1 -2 #3, 2d + 1s < 4}", REG_EXTENDED, 0);
  test_exec("3oifaowefbaoraofuiebofasebfaobfaorfeoaro",
	    0, REG_OK, 26, 33, 26, 33, END);

  /* Partially approximate matches. */
  test_comp("foo(bar){~1}zap", REG_EXTENDED, 0);
  test_exec("foobarzap", 0, REG_OK, 0, 9, 3, 6, END);
  test_exec("fobarzap", 0, REG_NOMATCH);
  test_exec("foobrzap", 0, REG_OK, 0, 8, 3, 5, END);
  test_comp("^.*(dot.org){~}.*$", REG_EXTENDED, 0);
  test_exec("www.cnn.com 64.236.16.20\n"
	    "www.slashdot.org 66.35.250.150\n"
	    "For useful information, use www.slashdot.org\n"
	    "this is demo data!\n",
	    0, REG_OK, 0, 120, 93, 100, END);

  /* Approximate matching and back referencing cannot be used together. */
  test_comp("(foo{~})\\1", REG_EXTENDED, REG_BADPAT);

#endif /* TRE_APPROX */

  /*
   * Basic tests with pure regular expressions
   */

  /* Basic string matching. */
  test_comp("foobar", REG_EXTENDED, 0);
  test_exec("foobar", 0, REG_OK, 0, 6, END);
  test_exec("xxxfoobarzapzot", 0, REG_OK, 3, 9, END);
  test_comp("foobar", REG_EXTENDED | REG_NOSUB, 0);
  test_exec("foobar", 0, REG_OK, END);
  test_comp("aaaa", REG_EXTENDED, 0);
  test_exec("xxaaaaaaaaaaaaaaaaa", 0, REG_OK, 2, 6, END);

  /* Test zero length matches. */
  test_comp("(a*)", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, END);

  test_comp("(a*)*", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, END);

  test_comp("((a*)*)*", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, 0, 0, END);
  test_comp("(a*bcd)*", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaaaabcxbcxbcxaabcxaabcx", 0, REG_OK, 0, 0, -1, -1, END);
  test_exec("aaaaaaaaaaaabcxbcxbcxaabcxaabc", 0, REG_OK, 0, 0, -1, -1, END);
  test_exec("aaaaaaaaaaaabcxbcdbcxaabcxaabc", 0, REG_OK, 0, 0, -1, -1, END);
  test_exec("aaaaaaaaaaaabcdbcdbcxaabcxaabc", 0, REG_OK, 0, 18, 15, 18, END);

  test_comp("(a*)+", REG_EXTENDED, 0);
  test_exec("-", 0, REG_OK, 0, 0, 0, 0, END);

  /* This test blows up the backtracking matcher. */
  avoid_eflags = REG_BACKTRACKING_MATCHER;
  test_comp("((a*)*b)*b", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaaaaaaaaaaaaaaaaab", 0, REG_OK,
	    25, 26, -1, -1, -1, -1, END);
  avoid_eflags = 0;

  test_comp("", 0, 0);
  test_exec("", 0, REG_OK, 0, 0, END);
  test_exec("foo", 0, REG_OK, 0, 0, END);

  /* Test for submatch addressing which requires arbitrary lookahead. */
  test_comp("(a*)aaaaaa", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaaaaaaax", 0, REG_OK, 0, 15, 0, 9, END);

  /* Test leftmost and longest matching and some tricky submatches. */
  test_comp("(a*)(a*)", REG_EXTENDED, 0);
  test_exec("aaaa", 0, REG_OK, 0, 4, 0, 4, 4, 4, END);
  test_comp("(abcd|abc)(d?)", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 4, 0, 4, 4, 4, END);
  test_comp("(abc|abcd)(d?)", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 4, 0, 4, 4, 4, END);
  test_comp("(abc|abcd)(d?)e", REG_EXTENDED, 0);
  test_exec("abcde", 0, REG_OK, 0, 5, 0, 4, 4, 4, END);
  test_comp("(abcd|abc)(d?)e", REG_EXTENDED, 0);
  test_exec("abcde", 0, REG_OK, 0, 5, 0, 4, 4, 4, END);
  test_comp("a(bc|bcd)(d?)", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 4, 1, 4, 4, 4, END);
  test_comp("a(bcd|bc)(d?)", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 4, 1, 4, 4, 4, END);
  test_comp("a*(a?bc|bcd)(d?)", REG_EXTENDED, 0);
  test_exec("aaabcd", 0, REG_OK, 0, 6, 3, 6, 6, 6, END);
  test_comp("a*(bcd|a?bc)(d?)", REG_EXTENDED, 0);
  test_exec("aaabcd", 0, REG_OK, 0, 6, 3, 6, 6, 6, END);
  test_comp("(a|(a*b*))*", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, 0, 0, END);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, -1, -1, END);
  test_exec("aa", 0, REG_OK, 0, 2, 0, 2, 0, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, 0, 3, 0, 3, END);
  test_exec("bbb", 0, REG_OK, 0, 3, 0, 3, 0, 3, END);
  test_exec("aaabbb", 0, REG_OK, 0, 6, 0, 6, 0, 6, END);
  test_exec("bbbaaa", 0, REG_OK, 0, 6, 3, 6, 3, 6, END);
  test_comp("((a*b*)|a)*", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, 0, 0, END);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, 0, 1, END);
  test_exec("aa", 0, REG_OK, 0, 2, 0, 2, 0, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, 0, 3, 0, 3, END);
  test_exec("bbb", 0, REG_OK, 0, 3, 0, 3, 0, 3, END);
  test_exec("aaabbb", 0, REG_OK, 0, 6, 0, 6, 0, 6, END);
  test_exec("bbbaaa", 0, REG_OK, 0, 6, 3, 6, 3, 6, END);
  test_comp("a.*(.*b.*(.*c.*).*d.*).*e.*(.*f.*).*g", REG_EXTENDED, 0);
  test_exec("aabbccddeeffgg", 0, REG_OK, 0, 14, 3, 9, 5, 7, 11, 13, END);
  test_comp("(wee|week)(night|knights)s*", REG_EXTENDED, 0);
  test_exec("weeknights", 0, REG_OK, 0, 10, 0, 3, 3, 10, END);
  test_exec("weeknightss", 0, REG_OK, 0, 11, 0, 3, 3, 10, END);
  test_comp("a*", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaa", 0, REG_OK, 0, 10, END);
  test_comp("aa*", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaa", 0, REG_OK, 0, 10, END);
  test_comp("aaa*", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaa", 0, REG_OK, 0, 10, END);
  test_comp("aaaa*", REG_EXTENDED, 0);
  test_exec("aaaaaaaaaa", 0, REG_OK, 0, 10, END);

  /* Test clearing old submatch data with nesting parentheses
     and iteration. */
  test_comp("((a)|(b))*c", REG_EXTENDED, 0);
  test_exec("aaabc", 0, REG_OK, 0, 5, 3, 4, -1, -1, 3, 4, END);
  test_exec("aaaac", 0, REG_OK, 0, 5, 3, 4, 3, 4, -1, -1, END);
  test_comp("foo((bar)*)*zot", REG_EXTENDED, 0);
  test_exec("foozot", 0, REG_OK, 0, 6, 3, 3, -1, -1, END);
  test_exec("foobarzot", 0, REG_OK, 0, 9, 3, 6, 3, 6, END);
  test_exec("foobarbarzot", 0, REG_OK, 0, 12, 3, 9, 6, 9, END);

  test_comp("foo((zup)*|(bar)*|(zap)*)*zot", REG_EXTENDED, 0);
  test_exec("foobarzapzot", 0, REG_OK,
	    0, 12, 6, 9, -1, -1, -1, -1, 6, 9, END);
  test_exec("foobarbarzapzot", 0, REG_OK,
	    0, 15, 9, 12, -1, -1, -1, -1, 9, 12, END);
  test_exec("foozupzot", 0, REG_OK,
	    0, 9, 3, 6, 3, 6, -1, -1, -1, -1, END);
  test_exec("foobarzot", 0, REG_OK,
	    0, 9, 3, 6, -1, -1, 3, 6, -1, -1, END);
  test_exec("foozapzot", 0, REG_OK,
	    0, 9, 3, 6, -1, -1, -1, -1, 3, 6, END);
  test_exec("foozot", 0, REG_OK,
	    0, 6, 3, 3, -1, -1, -1, -1, -1, -1, END);


  /* Test case where, e.g., Perl and Python regexp functions, and many
     other backtracking matchers, fail to produce the longest match.
     It is not exactly a bug since Perl does not claim to find the
     longest match, but a confusing feature and, in my opinion, a bad
     design choice because the union operator is traditionally defined
     to be commutative (with respect to the language denoted by the RE). */
  test_comp("(a|ab)(blip)?", REG_EXTENDED, 0);
  test_exec("ablip", 0, REG_OK, 0, 5, 0, 1, 1, 5, END);
  test_exec("ab", 0, REG_OK, 0, 2, 0, 2, -1, -1, END);
  test_comp("(ab|a)(blip)?", REG_EXTENDED, 0);
  test_exec("ablip", 0, REG_OK, 0, 5, 0, 1, 1, 5, END);
  test_exec("ab", 0, REG_OK, 0, 2, 0, 2, -1, -1, END);

  /* Test more submatch addressing. */
  test_comp("((a|b)*)a(a|b)*", REG_EXTENDED, 0);
  test_exec("aaaaabaaaba", 0, REG_OK, 0, 11, 0, 10, 9, 10, -1, -1, END);
  test_exec("aaaaabaaab", 0, REG_OK, 0, 10, 0, 8, 7, 8, 9, 10, END);
  test_exec("caa", 0, REG_OK, 1, 3, 1, 2, 1, 2, -1, -1, END);
  test_comp("((a|aba)*)(ababbaba)((a|b)*)", REG_EXTENDED, 0);
  test_exec("aabaababbabaaababbab", 0, REG_OK,
	    0, 20, 0, 4, 1, 4, 4, 12, 12, 20, 19, 20, END);
  test_exec("aaaaababbaba", 0, REG_OK,
	    0, 12, 0, 4, 3, 4, 4, 12, 12, 12, -1, -1, END);
  test_comp("((a|aba|abb|bba|bab)*)(ababbababbabbbabbbbbbabbaba)((a|b)*)",
	    REG_EXTENDED, 0);
  test_exec("aabaabbbbabababaababbababbabbbabbbbbbabbabababbababababbabababa",
	    0, REG_OK, 0, 63, 0, 16, 13, 16, 16, 43, 43, 63, 62, 63, END);

  /* Test for empty subexpressions. */
  test_comp("", 0, 0);
  test_exec("", 0, REG_OK, 0, 0, END);
  test_exec("foo", 0, REG_OK, 0, 0, END);
  test_comp("(a|)", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, END);
  test_exec("b", 0, REG_OK, 0, 0, 0, 0, END);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, END);
  test_comp("a|", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_exec("b", 0, REG_OK, 0, 0, END);
  test_exec("", 0, REG_OK, 0, 0, END);
  test_comp("|a", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_exec("b", 0, REG_OK, 0, 0, END);
  test_exec("", 0, REG_OK, 0, 0, END);

  /* Miscellaneous tests. */
  test_comp("(a*)b(c*)", REG_EXTENDED, 0);
  test_exec("abc", 0, REG_OK, 0, 3, 0, 1, 2, 3, END);
  test_exec("***abc***", 0, REG_OK, 3, 6, 3, 4, 5, 6, END);
  test_comp("(a)", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, END);
  test_comp("((a))", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, 0, 1, END);
  test_comp("(((a)))", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, 0, 1, 0, 1, END);
  test_comp("((((((((((((((((((((a))))))))))))))))))))", REG_EXTENDED, 0);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
	    0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
	    0, 1, 0, 1, 0, 1, END);

  test_comp("ksntoeaiksntoeaikstneoaiksnteoaiksntoeaiskntoeaiskntoekainstoei"
	    "askntoeakisntoeksaitnokesantiksoentaikosentaiksoentaiksnoeaiskn"
	    "teoaksintoekasitnoeksaitkosetniaksoetnaisknoetakistoeksintokesa"
	    "nitksoentaisknoetaisknoetiaksotneaikstoekasitoeskatioksentaikso"
	    "enatiksoetnaiksonateiksoteaeskanotisknetaiskntoeasknitoskenatis"
	    "konetaisknoteai", 0, 0);

  test_comp("((aab)|(aac)|(aa*))c", REG_EXTENDED, 0);
  test_exec("aabc", 0, REG_OK, 0, 4, 0, 3,  0,	3, -1, -1, -1, -1, END);
  test_exec("aacc", 0, REG_OK, 0, 4, 0, 3, -1, -1,  0,	3, -1, -1, END);
  test_exec("aaac", 0, REG_OK, 0, 4, 0, 3, -1, -1, -1, -1,  0,	3, END);

  test_comp("^(([^!]+!)?([^!]+)|.+!([^!]+!)([^!]+))$",
	    REG_EXTENDED, 0);
  test_exec("foo!bar!bas", 0, REG_OK,
	    0, 11, 0, 11, -1, -1, -1, -1, 4, 8, 8, 11, END);
  test_comp("^([^!]+!)?([^!]+)$|^.+!([^!]+!)([^!]+)$",
	    REG_EXTENDED, 0);
  test_exec("foo!bar!bas", 0, REG_OK,
	    0, 11, -1, -1, -1, -1, 4, 8, 8, 11, END);
  test_comp("^(([^!]+!)?([^!]+)|.+!([^!]+!)([^!]+))$",
	    REG_EXTENDED, 0);
  test_exec("foo!bar!bas", 0, REG_OK,
	    0, 11, 0, 11, -1, -1, -1, -1, 4, 8, 8, 11, END);

  test_comp("M[ou]'?am+[ae]r .*([AEae]l[- ])?[GKQ]h?[aeu]+([dtz][dhz]?)+af[iy]",
	    REG_EXTENDED, 0);
  test_exec("Muammar Quathafi", 0, REG_OK, 0, 16, -1, -1, 11, 13, END);

  test_comp("(Ab|cD)*", REG_EXTENDED | REG_ICASE, 0);
  test_exec("aBcD", 0, REG_OK, 0, 4, 2, 4, END);

  test_comp("a**", REG_EXTENDED, REG_BADRPT);
  test_comp("a*+", REG_EXTENDED, REG_BADRPT);
  test_comp("a+*", REG_EXTENDED, REG_BADRPT);
  test_comp("a++", REG_EXTENDED, REG_BADRPT);
  test_comp("a?+", REG_EXTENDED, REG_BADRPT);
  test_comp("a?*", REG_EXTENDED, REG_BADRPT);
  test_comp("a{1,2}*", REG_EXTENDED, REG_BADRPT);
  test_comp("a{1,2}+", REG_EXTENDED, REG_BADRPT);

  /*
   * Many of the following tests were mostly inspired by (or copied from) the
   * libhackerlab posix test suite by Tom Lord.
   */

  test_comp("a", 0, 0);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_comp("\\.", 0, 0);
  test_exec(".", 0, REG_OK, 0, 1, END);
  test_comp("\\[", 0, 0);
  test_exec("[", 0, REG_OK, 0, 1, END);
  test_comp("\\\\", 0, 0);
  test_exec("\\", 0, REG_OK, 0, 1, END);
  test_comp("\\*", 0, 0);
  test_exec("*", 0, REG_OK, 0, 1, END);
  test_comp("\\^", 0, 0);
  test_exec("^", 0, REG_OK, 0, 1, END);
  test_comp("\\$", 0, 0);
  test_exec("$", 0, REG_OK, 0, 1, END);

  test_comp("\\", 0, REG_EESCAPE);

  test_comp("x\\.", 0, 0);
  test_exec("x.", 0, REG_OK, 0, 2, END);
  test_comp("x\\[", 0, 0);
  test_exec("x[", 0, REG_OK, 0, 2, END);
  test_comp("x\\\\", 0, 0);
  test_exec("x\\", 0, REG_OK, 0, 2, END);
  test_comp("x\\*", 0, 0);
  test_exec("x*", 0, REG_OK, 0, 2, END);
  test_comp("x\\^", 0, 0);
  test_exec("x^", 0, REG_OK, 0, 2, END);
  test_comp("x\\$", 0, 0);
  test_exec("x$", 0, REG_OK, 0, 2, END);

  test_comp("x\\", 0, REG_EESCAPE);

  test_comp(".", 0, 0);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_exec("\n", 0, REG_OK, 0, 1, END);

  test_comp("(+|?)", 0, 0);
  test_exec("(+|?)", 0, REG_OK, 0, 5, END);
  test_exec("+|?", 0, REG_NOMATCH);
  test_exec("(+)", 0, REG_NOMATCH);
  test_exec("+", 0, REG_NOMATCH);


  /*
   * Test bracket expressions.
   */

  test_comp("[", 0, REG_EBRACK);
  test_comp("[]", 0, REG_EBRACK);
  test_comp("[^]", 0, REG_EBRACK);

  test_comp("[]x]", 0, 0);
  test_exec("]", 0, REG_OK, 0, 1, END);
  test_exec("x", 0, REG_OK, 0, 1, END);

  test_comp("[.]", 0, 0);
  test_exec(".", 0, REG_OK, 0, 1, END);
  test_exec("a", 0, REG_NOMATCH);

  test_comp("[*]", 0, 0);
  test_exec("*", 0, REG_OK, 0, 1, END);

  test_comp("[[]", 0, 0);
  test_exec("[", 0, REG_OK, 0, 1, END);

  test_comp("[\\]", 0, 0);
  test_exec("\\", 0, REG_OK, 0, 1, END);

  test_comp("[-x]", 0, 0);
  test_exec("-", 0, REG_OK, 0, 1, END);
  test_exec("x", 0, REG_OK, 0, 1, END);
  test_comp("[x-]", 0, 0);
  test_exec("-", 0, REG_OK, 0, 1, END);
  test_exec("x", 0, REG_OK, 0, 1, END);
  test_comp("[-]", 0, 0);
  test_exec("-", 0, REG_OK, 0, 1, END);

  test_comp("[abc]", 0, 0);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_exec("b", 0, REG_OK, 0, 1, END);
  test_exec("c", 0, REG_OK, 0, 1, END);
  test_exec("d", 0, REG_NOMATCH);
  test_exec("xa", 0, REG_OK, 1, 2, END);
  test_exec("xb", 0, REG_OK, 1, 2, END);
  test_exec("xc", 0, REG_OK, 1, 2, END);
  test_exec("xd", 0, REG_NOMATCH);
  test_comp("x[abc]", 0, 0);
  test_exec("xa", 0, REG_OK, 0, 2, END);
  test_exec("xb", 0, REG_OK, 0, 2, END);
  test_exec("xc", 0, REG_OK, 0, 2, END);
  test_exec("xd", 0, REG_NOMATCH);
  test_comp("[^abc]", 0, 0);
  test_exec("a", 0, REG_NOMATCH);
  test_exec("b", 0, REG_NOMATCH);
  test_exec("c", 0, REG_NOMATCH);
  test_exec("d", 0, REG_OK, 0, 1, END);
  test_exec("xa", 0, REG_OK, 0, 1, END);
  test_exec("xb", 0, REG_OK, 0, 1, END);
  test_exec("xc", 0, REG_OK, 0, 1, END);
  test_exec("xd", 0, REG_OK, 0, 1, END);
  test_comp("x[^abc]", 0, 0);
  test_exec("xa", 0, REG_NOMATCH);
  test_exec("xb", 0, REG_NOMATCH);
  test_exec("xc", 0, REG_NOMATCH);
  test_exec("xd", 0, REG_OK, 0, 2, END);

  test_comp("[()+?*\\]+", REG_EXTENDED, 0);
  test_exec("x\\*?+()x", 0, REG_OK, 1, 7, END);

  /* Standard character classes. */
  test_comp("[[:alnum:]]+", REG_EXTENDED, 0);
  test_exec("%abc123890XYZ=", 0, REG_OK, 1, 13, END);
  test_comp("[[:cntrl:]]+", REG_EXTENDED, 0);
  test_exec("%\n\t\015\f ", 0, REG_OK, 1, 5, END);
  test_comp("[[:lower:]]+", REG_EXTENDED, 0);
  test_exec("AbcdE", 0, REG_OK, 1, 4, END);
  test_comp("[[:lower:]]+", REG_EXTENDED | REG_ICASE, 0);
  test_exec("AbcdE", 0, REG_OK, 0, 5, END);
  test_comp("[[:space:]]+", REG_EXTENDED, 0);
  test_exec("x \t\f\nx", 0, REG_OK, 1, 5, END);
  test_comp("[[:alpha:]]+", REG_EXTENDED, 0);
  test_exec("%abC123890xyz=", 0, REG_OK, 1, 4, END);
  test_comp("[[:digit:]]+", REG_EXTENDED, 0);
  test_exec("%abC123890xyz=", 0, REG_OK, 4, 10, END);
  test_comp("[^[:digit:]]+", REG_EXTENDED, 0);
  test_exec("%abC123890xyz=", 0, REG_OK, 0, 4, END);
  test_comp("[[:print:]]+", REG_EXTENDED, 0);
  test_exec("\n %abC12\f", 0, REG_OK, 1, 8, END);
  test_comp("[[:upper:]]+", REG_EXTENDED, 0);
  test_exec("\n aBCDEFGHIJKLMNOPQRSTUVWXYz", 0, REG_OK, 3, 27, END);
  test_comp("[[:upper:]]+", REG_EXTENDED | REG_ICASE, 0);
  test_exec("\n aBCDEFGHIJKLMNOPQRSTUVWXYz", 0, REG_OK, 2, 28, END);
#ifdef HAVE_ISWBLANK
#ifdef HAVE_ISBLANK
  test_comp("[[:blank:]]+", REG_EXTENDED, 0);
  test_exec("\na \t b", 0, REG_OK, 2, 5, END);
#endif /* HAVE_ISBLANK */
#endif /* HAVE_ISWBLANK */
  test_comp("[[:graph:]]+", REG_EXTENDED, 0);
  test_exec("\n %abC12\f", 0, REG_OK, 2, 8, END);
  test_comp("[[:punct:]]+", REG_EXTENDED, 0);
  test_exec("a~!@#$%^&*()_+=-`[]{};':\"|\\,./?>< ",
	    0, REG_OK, 1, 33, END);
  test_comp("[[:xdigit:]]+", REG_EXTENDED, 0);
  test_exec("-0123456789ABCDEFabcdef", 0, REG_OK, 1, 23, END);
  test_comp("[[:bogus-character-class-name:]", REG_EXTENDED, REG_ECTYPE);


  /* Range expressions (assuming that the C locale is being used). */
  test_comp("[a-z]+", REG_EXTENDED, 0);
  test_exec("ABCabcxyzABC", 0, REG_OK, 3, 9, END);
  test_comp("[z-a]+", REG_EXTENDED, REG_ERANGE);
  test_comp("[a-b-c]", 0, REG_ERANGE);
  test_comp("[a-a]+", REG_EXTENDED, 0);
  test_exec("zaaaaab", 0, REG_OK, 1, 6, END);
  test_comp("[--Z]+", REG_EXTENDED, 0);
  test_exec("!ABC-./XYZ~", 0, REG_OK, 1, 10, END);
  test_comp("[*--]", 0, 0);
  test_exec("-", 0, REG_OK, 0, 1, END);
  test_exec("*", 0, REG_OK, 0, 1, END);
  test_comp("[*--Z]+", REG_EXTENDED, 0);
  test_exec("!+*,---ABC", 0, REG_OK, 1, 7, END);
  test_comp("[a-]+", REG_EXTENDED, 0);
  test_exec("xa-a--a-ay", 0, REG_OK, 1, 9, END);

  /* REG_ICASE and character sets. */
  test_comp("[a-c]*", REG_ICASE | REG_EXTENDED, 0);
  test_exec("cABbage", 0, REG_OK, 0, 5, END);
  test_comp("[^a-c]*", REG_ICASE | REG_EXTENDED, 0);
  test_exec("tObAcCo", 0, REG_OK, 0, 2, END);
  test_comp("[A-C]*", REG_ICASE | REG_EXTENDED, 0);
  test_exec("cABbage", 0, REG_OK, 0, 5, END);
  test_comp("[^A-C]*", REG_ICASE | REG_EXTENDED, 0);
  test_exec("tObAcCo", 0, REG_OK, 0, 2, END);

  /* Complex character sets. */
  test_comp("[[:digit:]a-z#$%]+", REG_EXTENDED, 0);
  test_exec("__abc#lmn012$x%yz789*", 0, REG_OK, 2, 20, END);
  test_comp("[[:digit:]a-z#$%]+", REG_ICASE | REG_EXTENDED, 0);
  test_exec("__abcLMN012x%#$yz789*", 0, REG_OK, 2, 20, END);
  test_comp("[^[:digit:]a-z#$%]+", REG_EXTENDED, 0);
  test_exec("abc#lmn012$x%yz789--@*,abc", 0, REG_OK, 18, 23, END);
  test_comp("[^[:digit:]a-z#$%]+", REG_ICASE | REG_EXTENDED, 0);
  test_exec("abc#lmn012$x%yz789--@*,abc", 0, REG_OK, 18, 23, END);
  test_comp("[^[:digit:]#$%[:xdigit:]]+", REG_ICASE | REG_EXTENDED, 0);
  test_exec("abc#lmn012$x%yz789--@*,abc", 0, REG_OK, 4, 7, END);
  test_comp("[^-]+", REG_EXTENDED, 0);
  test_exec("---afd*(&,ml---", 0, REG_OK, 3, 12, END);
  test_comp("[^--Z]+", REG_EXTENDED, 0);
  test_exec("---AFD*(&,ml---", 0, REG_OK, 6, 12, END);
  test_comp("[^--Z]+", REG_ICASE | REG_EXTENDED, 0);
  test_exec("---AFD*(&,ml---", 0, REG_OK, 6, 10, END);

  /* Unsupported things (equivalence classes and multicharacter collating
     elements) */
  test_comp("[[.foo.]]", 0, REG_ECOLLATE);
  test_comp("[[=foo=]]", 0, REG_ECOLLATE);
  test_comp("[[..]]", 0, REG_ECOLLATE);
  test_comp("[[==]]", 0, REG_ECOLLATE);
  test_comp("[[.]]", 0, REG_ECOLLATE);
  test_comp("[[=]]", 0, REG_ECOLLATE);
  test_comp("[[.]", 0, REG_ECOLLATE);
  test_comp("[[=]", 0, REG_ECOLLATE);
  test_comp("[[.", 0, REG_ECOLLATE);
  test_comp("[[=", 0, REG_ECOLLATE);



  /* Miscellaneous tests. */
  test_comp("abc\\(\\(de\\)\\(fg\\)\\)hi", 0, 0);
  test_exec("xabcdefghiy", 0, REG_OK, 1, 10, 4, 8, 4, 6, 6, 8, END);

  test_comp("abc*def", 0, 0);
  test_exec("xabdefy", 0, REG_OK, 1, 6, END);
  test_exec("xabcdefy", 0, REG_OK, 1, 7, END);
  test_exec("xabcccccccdefy", 0, REG_OK, 1, 13, END);

  test_comp("abc\\(def\\)*ghi", 0, 0);
  test_exec("xabcghiy", 0, REG_OK, 1, 7, -1, -1, END);
  test_exec("xabcdefghi", 0, REG_OK, 1, 10, 4, 7, END);
  test_exec("xabcdefdefdefghi", 0, REG_OK, 1, 16, 10, 13, END);

  test_comp("a?", REG_EXTENDED, REG_OK);
  test_exec("aaaaa", 0, REG_OK, 0, 1, END);
  test_exec("xaaaaa", 0, REG_OK, 0, 0, END);
  test_comp("a+", REG_EXTENDED, REG_OK);
  test_exec("aaaaa", 0, REG_OK, 0, 5, END);
  test_exec("xaaaaa", 0, REG_OK, 1, 6, END);


  /*
   * Test anchors and their behaviour with the REG_NEWLINE compilation
   * flag and the REG_NOTBOL, REG_NOTEOL execution flags.
   */

  /* Normally, `^' matches the empty string at beginning of input.
     If REG_NOTBOL is used, `^' won't match the zero length string. */
  test_comp("^abc", 0, 0);
  test_exec("abcdef", 0, REG_OK, 0, 3, END);
  test_exec("abcdef", REG_NOTBOL, REG_NOMATCH);
  test_exec("xyzabcdef", 0, REG_NOMATCH);
  test_exec("xyzabcdef", REG_NOTBOL, REG_NOMATCH);
  test_exec("\nabcdef", 0, REG_NOMATCH);
  test_exec("\nabcdef", REG_NOTBOL, REG_NOMATCH);

  /* Normally, `$' matches the empty string at end of input.
     If REG_NOTEOL is used, `$' won't match the zero length string. */
  test_comp("abc$", 0, 0);
  test_exec("defabc", 0, REG_OK, 3, 6, END);
  test_exec("defabc", REG_NOTEOL, REG_NOMATCH);
  test_exec("defabcxyz", 0, REG_NOMATCH);
  test_exec("defabcxyz", REG_NOTEOL, REG_NOMATCH);
  test_exec("defabc\n", 0, REG_NOMATCH);
  test_exec("defabc\n", REG_NOTEOL, REG_NOMATCH);

  test_comp("^abc$", 0, 0);
  test_exec("abc", 0, REG_OK, 0, 3, END);
  test_exec("abc", REG_NOTBOL, REG_NOMATCH);
  test_exec("abc", REG_NOTEOL, REG_NOMATCH);
  test_exec("abc", REG_NOTBOL | REG_NOTEOL, REG_NOMATCH);
  test_exec("\nabc\n", 0, REG_NOMATCH);
  test_exec("defabc\n", 0, REG_NOMATCH);
  test_exec("\nabcdef", 0, REG_NOMATCH);
  test_exec("abcdef", 0, REG_NOMATCH);
  test_exec("defabc", 0, REG_NOMATCH);
  test_exec("abc\ndef", 0, REG_NOMATCH);
  test_exec("def\nabc", 0, REG_NOMATCH);

  /* If REG_NEWLINE is used, `^' matches the empty string immediately after
     a newline, regardless of whether execution flags contain REG_NOTBOL.
     Similarly, if REG_NEWLINE is used, `$' matches the empty string
     immediately before a newline, regardless of execution flags. */
  test_comp("^abc", REG_NEWLINE, 0);
  test_exec("abcdef", 0, REG_OK, 0, 3, END);
  test_exec("abcdef", REG_NOTBOL, REG_NOMATCH);
  test_exec("xyzabcdef", 0, REG_NOMATCH);
  test_exec("xyzabcdef", REG_NOTBOL, REG_NOMATCH);
  test_exec("\nabcdef", 0, REG_OK, 1, 4, END);
  test_exec("\nabcdef", REG_NOTBOL, 0, 1, 4, END);
  test_comp("abc$", REG_NEWLINE, 0);
  test_exec("defabc", 0, REG_OK, 3, 6, END);
  test_exec("defabc", REG_NOTEOL, REG_NOMATCH);
  test_exec("defabcxyz", 0, REG_NOMATCH);
  test_exec("defabcxyz", REG_NOTEOL, REG_NOMATCH);
  test_exec("defabc\n", 0, REG_OK, 3, 6, END);
  test_exec("defabc\n", REG_NOTEOL, 0, 3, 6, END);
  test_comp("^abc$", REG_NEWLINE, 0);
  test_exec("abc", 0, REG_OK, 0, 3, END);
  test_exec("abc", REG_NOTBOL, REG_NOMATCH);
  test_exec("abc", REG_NOTEOL, REG_NOMATCH);
  test_exec("abc", REG_NOTBOL | REG_NOTEOL, REG_NOMATCH);
  test_exec("\nabc\n", 0, REG_OK, 1, 4, END);
  test_exec("defabc\n", 0, REG_NOMATCH);
  test_exec("\nabcdef", 0, REG_NOMATCH);
  test_exec("abcdef", 0, REG_NOMATCH);
  test_exec("abcdef", REG_NOTBOL, REG_NOMATCH);
  test_exec("defabc", 0, REG_NOMATCH);
  test_exec("defabc", REG_NOTEOL, REG_NOMATCH);
  test_exec("abc\ndef", 0, REG_OK, 0, 3, END);
  test_exec("abc\ndef", REG_NOTBOL, REG_NOMATCH);
  test_exec("abc\ndef", REG_NOTEOL, 0, 0, 3, END);
  test_exec("abc\ndef", REG_NOTBOL | REG_NOTEOL, REG_NOMATCH);
  test_exec("def\nabc", 0, REG_OK, 4, 7, END);
  test_exec("def\nabc", REG_NOTBOL, 0, 4, 7, END);
  test_exec("def\nabc", REG_NOTEOL, REG_NOMATCH);
  test_exec("def\nabc", REG_NOTBOL | REG_NOTEOL, REG_NOMATCH);

  /* With BRE syntax, `^' has a special meaning only at the beginning of the
     RE or the beginning of a parenthesized subexpression. */
  test_comp("a\\{0,1\\}^bc", 0, 0);
  test_exec("bc", 0, REG_NOMATCH);
  test_exec("^bc", 0, REG_OK, 0, 3, END);
  test_exec("abc", 0, REG_NOMATCH);
  test_exec("a^bc", 0, REG_OK, 0, 4, END);
  test_comp("a\\{0,1\\}\\(^bc\\)", 0, 0);
  test_exec("bc", 0, REG_OK, 0, 2, 0, 2, END);
  test_exec("^bc", 0, REG_NOMATCH);
  test_exec("abc", 0, REG_NOMATCH);
  test_exec("a^bc", 0, REG_NOMATCH);
  test_comp("(^a", 0, 0);
  test_exec("(^a", 0, REG_OK, 0, 3, END);

  /* With BRE syntax, `$' has a special meaning only at the end of the
     RE or the end of a parenthesized subexpression. */
  test_comp("ab$c\\{0,1\\}", 0, 0);
  test_exec("ab", 0, REG_NOMATCH);
  test_exec("ab$", 0, REG_OK, 0, 3, END);
  test_exec("abc", 0, REG_NOMATCH);
  test_exec("ab$c", 0, REG_OK, 0, 4, END);
  test_comp("\\(ab$\\)c\\{0,1\\}", 0, 0);
  test_exec("ab", 0, REG_OK, 0, 2, 0, 2, END);
  test_exec("ab$", 0, REG_NOMATCH);
  test_exec("abc", 0, REG_NOMATCH);
  test_exec("ab$c", 0, REG_NOMATCH);
  test_comp("a$)", 0, 0);
  test_exec("a$)", 0, REG_OK, 0, 3, END);

  /* Miscellaneous tests for `^' and `$'. */
  test_comp("foo^$", REG_EXTENDED, 0);
  test_exec("foo", 0, REG_NOMATCH);
  test_comp("x$\n^y", REG_EXTENDED | REG_NEWLINE, 0);
  test_exec("foo\nybarx\nyes\n", 0, REG_OK, 8, 11, END);
  test_comp("^$", 0, 0);
  test_exec("x", 0, REG_NOMATCH);
  test_exec("", 0, REG_OK, 0, 0, END);
  test_exec("\n", 0, REG_NOMATCH);
  test_comp("^$", REG_NEWLINE, 0);
  test_exec("x", 0, REG_NOMATCH);
  test_exec("", 0, REG_OK, 0, 0, END);
  test_exec("\n", 0, REG_OK, 0, 0, END);

  /* REG_NEWLINE causes `.' not to match newlines. */
  test_comp(".*", 0, 0);
  test_exec("ab\ncd", 0, REG_OK, 0, 5, END);
  test_comp(".*", REG_NEWLINE, 0);
  test_exec("ab\ncd", 0, REG_OK, 0, 2, END);

  /*
   * Tests for nonstandard syntax extensions.
   */

  /* Zero width assertions. */
  test_comp("\\<x", REG_EXTENDED, 0);
  test_exec("aax xaa", 0, REG_OK, 4, 5, END);
  test_exec("xaa", 0, REG_OK, 0, 1, END);
  test_comp("x\\>", REG_EXTENDED, 0);
  test_exec("axx xaa", 0, REG_OK, 2, 3, END);
  test_exec("aax", 0, REG_OK, 2, 3, END);
  test_comp("\\bx", REG_EXTENDED, 0);
  test_exec("axx xaa", 0, REG_OK, 4, 5, END);
  test_exec("aax", 0, REG_NOMATCH);
  test_exec("xax", 0, REG_OK, 0, 1, END);
  test_comp("x\\b", REG_EXTENDED, 0);
  test_exec("axx xaa", 0, REG_OK, 2, 3, END);
  test_exec("aax", 0, REG_OK, 2, 3, END);
  test_exec("xaa", 0, REG_NOMATCH);
  test_comp("\\Bx", REG_EXTENDED, 0);
  test_exec("aax xxa", 0, REG_OK, 2, 3, END);
  test_comp("\\Bx\\b", REG_EXTENDED, 0);
  test_exec("aax xxx", 0, REG_OK, 2, 3, END);
  test_comp("\\<.", REG_EXTENDED, 0);
  test_exec(";xaa", 0, REG_OK, 1, 2, END);

  /* Shorthands for character classes. */
  test_comp("\\w+", REG_EXTENDED, 0);
  test_exec(",.(a23_Nt-öo)", 0, REG_OK, 3, 9, END);
  test_comp("\\d+", REG_EXTENDED, 0);
  test_exec("uR120_4=v4", 0, REG_OK, 2, 5, END);
  test_comp("\\D+", REG_EXTENDED, 0);
  test_exec("120d_=vA4s", 0, REG_OK, 3, 8, END);

  /* Quoted special characters. */
  test_comp("\\t", REG_EXTENDED, 0);
  test_comp("\\e", REG_EXTENDED, 0);

  /* Test the \x1B and \x{263a} extensions for specifying 8 bit and wide
     characters in hexadecimal. */
  test_comp("\\x41", REG_EXTENDED, 0);
  test_exec("ABC", 0, REG_OK, 0, 1, END);
  test_comp("\\x5", REG_EXTENDED, 0);
  test_exec("\005", 0, REG_OK, 0, 1, END);
  test_comp("\\x5r", REG_EXTENDED, 0);
  test_exec("\005r", 0, REG_OK, 0, 2, END);
  test_comp("\\x", REG_EXTENDED, 0);
  test_nexec("\000", 1, 0, REG_OK, 0, 1, END);
  test_comp("\\xr", REG_EXTENDED, 0);
  test_nexec("\000r", 2, 0, REG_OK, 0, 2, END);
  test_comp("\\x{41}", REG_EXTENDED, 0);
  test_exec("ABC", 0, REG_OK, 0, 1, END);
  test_comp("\\x{5}", REG_EXTENDED, 0);
  test_exec("\005", 0, REG_OK, 0, 1, END);
  test_comp("\\x{5}r", REG_EXTENDED, 0);
  test_exec("\005r", 0, REG_OK, 0, 2, END);
  test_comp("\\x{}", REG_EXTENDED, 0);
  test_nexec("\000", 1, 0, REG_OK, 0, 1, END);
  test_comp("\\x{}r", REG_EXTENDED, 0);
  test_nexec("\000r", 2, 0, REG_OK, 0, 2, END);

  /* Tests for (?inrU-inrU) and (?inrU-inrU:) */
  test_comp("foo(?i)bar", REG_EXTENDED, 0);
  test_exec("fooBaR", 0, REG_OK, 0, 6, END);
  test_comp("foo(?i)bar|zap", REG_EXTENDED, 0);
  test_exec("fooBaR", 0, REG_OK, 0, 6, END);
  test_exec("foozap", 0, REG_OK, 0, 6, END);
  test_exec("foozAp", 0, REG_OK, 0, 6, END);
  test_exec("zap", 0, REG_NOMATCH);
  test_comp("foo(?-i:zap)zot", REG_EXTENDED | REG_ICASE, 0);
  test_exec("FoOzapZOt", 0, REG_OK, 0, 9, END);
  test_exec("FoOzApZOt", 0, REG_NOMATCH);
  test_comp("foo(?i:bar|zap)", REG_EXTENDED, 0);
  test_exec("foozap", 0, REG_OK, 0, 6, END);
  test_exec("foobar", 0, REG_OK, 0, 6, END);
  test_exec("foobAr", 0, REG_OK, 0, 6, END);
  test_exec("fooZaP", 0, REG_OK, 0, 6, END);
  test_comp("foo(?U:o*)(o*)", REG_EXTENDED, 0);
  test_exec("foooo", 0, REG_OK, 0, 5, 3, 5, END);

  /* Test comment syntax. */
  test_comp("foo(?# This here is a comment. )bar", REG_EXTENDED, 0);
  test_exec("foobar", 0, REG_OK, 0, 6, END);

  /* Tests for \Q and \E. */
  test_comp("\\((\\Q)?:\\<[^$\\E)", REG_EXTENDED, 0);
  test_exec("()?:\\<[^$", 0, REG_OK, 0, 9, 1, 9, END);
  test_comp("\\Qabc\\E.*", REG_EXTENDED, 0);
  test_exec("abcdef", 0, REG_OK, 0, 6, END);
  test_comp("\\Qabc\\E.*|foo", REG_EXTENDED, 0);
  test_exec("parabc123wxyz", 0, REG_OK, 3, 13, END);
  test_exec("fooabc123wxyz", 0, REG_OK, 0, 3, END);

  /*
   * Test bounded repetitions.
   */

  test_comp("a{0,0}", REG_EXTENDED, REG_OK);
  test_exec("aaa", 0, REG_OK, 0, 0, END);
  test_comp("a{0,1}", REG_EXTENDED, REG_OK);
  test_exec("aaa", 0, REG_OK, 0, 1, END);
  test_comp("a{1,1}", REG_EXTENDED, REG_OK);
  test_exec("aaa", 0, REG_OK, 0, 1, END);
  test_comp("a{1,3}", REG_EXTENDED, REG_OK);
  test_exec("xaaaaa", 0, REG_OK, 1, 4, END);
  test_comp("a{0,3}", REG_EXTENDED, REG_OK);
  test_exec("aaaaa", 0, REG_OK, 0, 3, END);
  test_comp("a{0,}", REG_EXTENDED, REG_OK);
  test_exec("", 0, REG_OK, 0, 0, END);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_exec("aa", 0, REG_OK, 0, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, END);
  test_comp("a{1,}", REG_EXTENDED, REG_OK);
  test_exec("", 0, REG_NOMATCH);
  test_exec("a", 0, REG_OK, 0, 1, END);
  test_exec("aa", 0, REG_OK, 0, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, END);
  test_comp("a{2,}", REG_EXTENDED, REG_OK);
  test_exec("", 0, REG_NOMATCH);
  test_exec("a", 0, REG_NOMATCH);
  test_exec("aa", 0, REG_OK, 0, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, END);
  test_comp("a{3,}", REG_EXTENDED, REG_OK);
  test_exec("", 0, REG_NOMATCH);
  test_exec("a", 0, REG_NOMATCH);
  test_exec("aa", 0, REG_NOMATCH);
  test_exec("aaa", 0, REG_OK, 0, 3, END);
  test_exec("aaaa", 0, REG_OK, 0, 4, END);
  test_exec("aaaaa", 0, REG_OK, 0, 5, END);
  test_exec("aaaaaa", 0, REG_OK, 0, 6, END);
  test_exec("aaaaaaa", 0, REG_OK, 0, 7, END);

  test_comp("a{5,10}", REG_EXTENDED, REG_OK);
  test_comp("a{6,6}", REG_EXTENDED, REG_OK);
  test_exec("aaaaaaaaaaaa", 0, REG_OK, 0, 6, END);
  test_exec("xxaaaaaaaaaaaa", 0, REG_OK, 2, 8, END);
  test_exec("xxaaaaa", 0, REG_NOMATCH);
  test_comp("a{5,6}", REG_EXTENDED, REG_OK);
  test_exec("aaaaaaaaaaaa", 0, REG_OK, 0, 6, END);
  test_exec("xxaaaaaaaaaaaa", 0, REG_OK, 2, 8, END);
  test_exec("xxaaaaa", 0, REG_OK, 2, 7, END);
  test_exec("xxaaaa", 0, REG_NOMATCH);

  /* Trickier ones... */
  test_comp("([ab]{5,10})*b", REG_EXTENDED, REG_OK);
  test_exec("bbbbbabaaaaab", 0, REG_OK, 0, 13, 5, 12, END);
  test_exec("bbbbbbaaaaab", 0, REG_OK, 0, 12, 5, 11, END);
  test_exec("bbbbbbaaaab", 0, REG_OK, 0, 11, 0, 10, END);
  test_exec("bbbbbbaaab", 0, REG_OK, 0, 10, 0, 9, END);
  test_exec("bbbbbbaab", 0, REG_OK, 0, 9, 0, 8, END);
  test_exec("bbbbbbab", 0, REG_OK, 0, 8, 0, 7, END);

  test_comp("([ab]*)(ab[ab]{5,10})ba", REG_EXTENDED, REG_OK);
  test_exec("abbabbbabaabbbbbbbbbbbbbabaaaabab", 0, REG_OK,
	    0, 10, 0, 0, 0, 8, END);
  test_exec("abbabbbabaabbbbbbbbbbbbabaaaaabab", 0, REG_OK,
	    0, 32, 0, 23, 23, 30, END);
  test_exec("abbabbbabaabbbbbbbbbbbbabaaaabab", 0, REG_OK,
	    0, 24, 0, 10, 10, 22, END);
  test_exec("abbabbbabaabbbbbbbbbbbba", 0, REG_OK,
	    0, 24, 0, 10, 10, 22, END);

  /* Test repeating something that has submatches inside. */
  test_comp("(a){0,5}", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, -1, -1, END);
  test_exec("a", 0, REG_OK, 0, 1, 0, 1, END);
  test_exec("aa", 0, REG_OK, 0, 2, 1, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, 2, 3, END);
  test_exec("aaaa", 0, REG_OK, 0, 4, 3, 4, END);
  test_exec("aaaaa", 0, REG_OK, 0, 5, 4, 5, END);
  test_exec("aaaaaa", 0, REG_OK, 0, 5, 4, 5, END);

  test_comp("(a){2,3}", REG_EXTENDED, 0);
  test_exec("", 0, REG_NOMATCH);
  test_exec("a", 0, REG_NOMATCH);
  test_exec("aa", 0, REG_OK, 0, 2, 1, 2, END);
  test_exec("aaa", 0, REG_OK, 0, 3, 2, 3, END);
  test_exec("aaaa", 0, REG_OK, 0, 3, 2, 3, END);

  test_comp("\\(a\\)\\{4\\}", 0, 0);
  test_exec("aaaa", 0, REG_OK, 0, 4, 3, 4, END);

  test_comp("\\(a*\\)\\{2\\}", 0, 0);
  test_exec("a", 0, REG_OK, 0, 1, 1, 1, END);

  test_comp("((..)|(.)){2}", REG_EXTENDED, 0);
  test_exec("aa", 0, REG_OK, 0, 2, 1, 2, -1, -1, 1, 2, END);

  /* Nested repeats. */
  test_comp("(.){2}{3}", REG_EXTENDED, 0);
  test_exec("xxxxx", 0, REG_NOMATCH);
  test_exec("xxxxxx", 0, REG_OK, 0, 6, 5, 6, END);
  test_comp("(..){2}{3}", REG_EXTENDED, 0);
  test_exec("xxxxxxxxxxx", 0, REG_NOMATCH);
  test_exec("xxxxxxxxxxxx", 0, REG_OK, 0, 12, 10, 12, END);
  test_comp("((..){2}.){3}", REG_EXTENDED, 0);
  test_exec("xxxxxxxxxxxxxx", 0, REG_NOMATCH);
  test_exec("xxxxxxxxxxxxxxx", 0, REG_OK, 0, 15, 10, 15, 12, 14, END);
  test_comp("((..){1,2}.){3}", REG_EXTENDED, 0);
  test_exec("xxxxxxxx", 0, REG_NOMATCH);
  test_exec("xxxxxxxxx", 0, REG_OK, 0, 9, 6, 9, 6, 8, END);
  test_exec("xxxxxxxxxx", 0, REG_OK, 0, 9, 6, 9, 6, 8, END);
  test_exec("xxxxxxxxxxx", 0, REG_OK, 0, 11, 8, 11, 8, 10, END);
  test_comp("a{2}{2}x", REG_EXTENDED, 0);
  test_exec("", 0, REG_NOMATCH);
  test_exec("x", 0, REG_NOMATCH);
  test_exec("ax", 0, REG_NOMATCH);
  test_exec("aax", 0, REG_NOMATCH);
  test_exec("aaax", 0, REG_NOMATCH);
  test_exec("aaaax", 0, REG_OK, 0, 5, END);
  test_exec("aaaaax", 0, REG_OK, 1, 6, END);
  test_exec("aaaaaax", 0, REG_OK, 2, 7, END);
  test_exec("aaaaaaax", 0, REG_OK, 3, 8, END);
  test_exec("aaaaaaaax", 0, REG_OK, 4, 9, END);

  /* Repeats with iterations inside. */
  test_comp("([a-z]+){2,5}", REG_EXTENDED, 0);
  test_exec("a\n", 0, REG_NOMATCH);
  test_exec("aa\n", 0, REG_OK, 0, 2, 1, 2, END);

  /* Multiple repeats in one regexp. */
  test_comp("a{3}b{3}", REG_EXTENDED, 0);
  test_exec("aaabbb", 0, REG_OK, 0, 6, END);
  test_exec("aaabbbb", 0, REG_OK, 0, 6, END);
  test_exec("aaaabbb", 0, REG_OK, 1, 7, END);
  test_exec("aabbb", 0, REG_NOMATCH);
  test_exec("aaabb", 0, REG_NOMATCH);

  /* Test that different types of repetitions work correctly when used
     in the same regexp.  */
  test_comp("a{2}{2}xb+xc*xd?x", REG_EXTENDED, 0);
  test_exec("aaaaxbxcxdx", 0, REG_OK, 0, 11, END);
  test_exec("aaaxbxcxdx", 0, REG_NOMATCH);
  test_exec("aabxcxdx", 0, REG_NOMATCH);
  test_exec("aaaacxdx", 0, REG_NOMATCH);
  test_exec("aaaaxbdx", 0, REG_NOMATCH);
  test_comp("^!packet [0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3}\\.[0-9]{1,3} [0-9]+",
	    REG_EXTENDED, 0);
  test_exec("!packet 10.0.2.4 12765 ei voittoa", 0, REG_OK, 0, 22, END);

  /*
   * Back referencing tests.
   */
  test_comp("([a-z]*) \\1", REG_EXTENDED, 0);
  test_exec("foobar foobar", 0, REG_OK, 0, 13, 0, 6, END);

  /* Searching for a leftmost longest square (repeated string) */
  test_comp("(.*)\\1", REG_EXTENDED, 0);
  test_exec("foobarfoobar", 0, REG_OK, 0, 12, 0, 6, END);

  test_comp("a(b)*c\\1", REG_EXTENDED, 0);
  test_exec("acb", 0, REG_OK, 0, 2, -1, -1, END);
  test_exec("abbcbbb", 0, REG_OK, 0, 5, 2, 3, END);
  test_exec("abbdbd", 0, REG_NOMATCH);

  test_comp("([a-c]*)\\1", REG_EXTENDED, 0);
  test_exec("abcacdef", 0, REG_OK, 0, 0, 0, 0, END);
  test_exec("abcabcabcd", 0, REG_OK, 0, 6, 0, 3, END);

  test_comp("\\(a*\\)*\\(x\\)\\(\\1\\)", 0, 0);
  test_exec("x", 0, REG_OK, 0, 1, 0, 0, 0, 1, 1, 1, END);
#if KNOWN_BUG
  test_exec("ax", 0, REG_OK, 0, 2, 1, 1, 1, 2, 2, 2, END);
#endif

  test_comp("(a)\\1{1,2}", REG_EXTENDED, 0);
  test_exec("aabc", 0, REG_OK, 0, 2, 0, 1, END);

  test_comp("((.*)\\1)+", REG_EXTENDED, 0);
  test_exec("aa", 0, REG_OK, 0, 2, 0, 2, 0, 1, END);

#if KNOWN_BUG
  test_comp("()(\\1\\1)*", REG_EXTENDED, 0);
  test_exec("", 0, REG_OK, 0, 0, 0, 0, 0, 0, END);
#endif

  /* Check that back references work with REG_NOSUB. */
  test_comp("(o)\\1", REG_EXTENDED | REG_NOSUB, 0);
  test_exec("foobar", 0, REG_OK, END);
  test_comp("(o)\\1", REG_EXTENDED, 0);
  test_exec("foobar", 0, REG_OK, 1, 3, 1, 2, END);
  test_comp("(o)\\1", REG_EXTENDED, 0);
  test_exec("fobar", 0, REG_NOMATCH);

  test_comp("\\1foo", REG_EXTENDED, REG_ESUBREG);
  test_comp("\\1foo(bar)", REG_EXTENDED, 0);

  /* Back reference with zero-width assertion. */
  test_comp("(.)\\1$", REG_EXTENDED, 0);
  test_exec("foox", 0, REG_NOMATCH);
  test_exec("foo", 0, REG_OK, 1, 3, 1, 2, END);

  /* Back references together with {}. */
  test_comp("([0-9]{5})\\1", REG_EXTENDED, 0);
  test_exec("12345", 0, REG_NOMATCH);
  test_exec("1234512345", 0, REG_OK, 0, 10, 0, 5, END);
  test_comp("([0-9]{4})\\1", REG_EXTENDED, 0);
  test_exec("1234", 0, REG_NOMATCH);
  test_exec("12341234", 0, REG_OK, 0, 8, 0, 4, END);

  /*
   * Test minimal repetitions (non-greedy repetitions)
   */
  avoid_eflags = REG_BACKTRACKING_MATCHER | REG_APPROX_MATCHER;

  /* Basic .*/
  test_comp(".*?", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 0, END);
  test_comp(".+?", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 1, END);
  test_comp(".??", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 0, END);
  test_comp(".{2,5}?", REG_EXTENDED, 0);
  test_exec("abcd", 0, REG_OK, 0, 2, END);

  /* More complicated. */
  test_comp("<b>(.*?)</b>", REG_EXTENDED, 0);
  test_exec("<b>text1</b><b>text2</b>", 0, REG_OK, 0, 12, 3, 8, END);
  test_comp("a(.*?)(foo|bar|zap)", REG_EXTENDED, 0);
  test_exec("hubba wooga-booga zabar gafoo wazap", 0, REG_OK,
	    4, 23, 5, 20, 20, 23, END);

  /* Test REG_UNGREEDY. */
  test_comp(".*", REG_EXTENDED | REG_UNGREEDY, 0);
  test_exec("abcd", 0, REG_OK, 0, 0, END);
  test_comp(".*?", REG_EXTENDED | REG_UNGREEDY, 0);
  test_exec("abcd", 0, REG_OK, 0, 4, END);

  avoid_eflags = 0;


  /*
   * Error reporting tests.
   */

  test_comp("\\", REG_EXTENDED, REG_EESCAPE);
  test_comp("\\\\", REG_EXTENDED, REG_OK);
  test_exec("\\", 0, REG_OK, 0, 1, END);
  test_comp("(", REG_EXTENDED, REG_EPAREN);
  test_comp("(aaa", REG_EXTENDED, REG_EPAREN);
  test_comp(")", REG_EXTENDED, REG_OK);
  test_exec(")", 0, REG_OK, 0, 1, END);
  test_comp("a{1", REG_EXTENDED, REG_EBRACE);
  test_comp("a{1,x}", REG_EXTENDED, REG_BADBR);
  test_comp("a{1x}", REG_EXTENDED, REG_BADBR);
  test_comp("a{1,0}", REG_EXTENDED, REG_BADBR);
  test_comp("a{x}", REG_EXTENDED, REG_BADBR);
  test_comp("a{}", REG_EXTENDED, REG_BADBR);


  test_comp("\\", 0, REG_EESCAPE);
  test_comp("\\(", 0, REG_EPAREN);
  test_comp("\\)", 0, REG_EPAREN);
  test_comp("a\\{1", 0, REG_EBRACE);
  test_comp("a\\{1,x\\}", 0, REG_BADBR);
  test_comp("a\\{1x\\}", 0, REG_BADBR);
  test_comp("a\\{1,0\\}", 0, REG_BADBR);
  test_comp("a\\{x\\}", 0, REG_BADBR);
  test_comp("a\\{\\}", 0, REG_BADBR);




  /*
   * Internationalization tests.
   */

  /* This same test with the correct locale is below. */
  test_comp("µ¡+", REG_EXTENDED, 0);
  test_exec("¤³¤Î¾Þ¤Ï¡¢µ¡¡¦ÍøÊØÀ­¡¦¥»¥­", 0, REG_OK, 10, 13, END);

#if !defined(WIN32) && !defined(__OpenBSD__)
  if (setlocale(LC_CTYPE, "en_US.ISO-8859-1") != NULL)
    {
      printf("\nTesting LC_CTYPE en_US.ISO-8859-1\n");
      test_comp("aBCdeFghiJKlmnoPQRstuvWXyZåäö", REG_ICASE, 0);
      test_exec("abCDefGhiJKlmNoPqRStuVwXyzÅÄÖ", 0, REG_OK, 0, 29, END);
    }

#ifdef TRE_MULTIBYTE
  if (setlocale(LC_CTYPE, "ja_JP.eucjp") != NULL)
    {
      printf("\nTesting LC_CTYPE ja_JP.eucjp\n");
      /* I tried to make a test where implementations not aware of multibyte
	 character sets will fail.  I have no idea what the japanese text here
	 means, I took it from http://www.ipsec.co.jp/. */
      test_comp("µ¡+", REG_EXTENDED, 0);
      test_exec("¤³¤Î¾Þ¤Ï¡¢µ¡¡¦ÍøÊØÀ­¡¦¥»¥­", 0, REG_OK, 10, 12, END);

      test_comp("a", REG_EXTENDED, 0);
      test_nexec("foo\000bar", 7, 0, REG_OK, 5, 6, END);
      test_comp("c$", REG_EXTENDED, 0);
      test_exec("abc", 0, REG_OK, 2, 3, END);
    }
#endif /* TRE_MULTIBYTE */
#endif

  tre_regfree(&reobj);

  printf("\n");
  if (comp_errors || exec_errors)
    printf("%d (%d + %d) out of %d tests FAILED!\n",
	   comp_errors + exec_errors, comp_errors, exec_errors,
	   comp_tests + exec_tests);
  else
    printf("All %d tests passed.\n", comp_tests + exec_tests);


#ifdef MALLOC_DEBUGGING
  if (xmalloc_dump_leaks())
    return 1;
#endif /* MALLOC_DEBUGGING */

  return comp_errors || exec_errors;
}

/* EOF */