patch 8.2.3409: reading beyond end of line with invalid utf-8 character

Problem:    Reading beyond end of line with invalid utf-8 character.
Solution:   Check for NUL when advancing.

post2nfa(int *postfix, int *end, int nfa_calc_size)
{
    int		*p;
    int		mopen;
    int		mclose;
    Frag_T	*stack = NULL;
    Frag_T	*stackp = NULL;
    Frag_T	*stack_end = NULL;
    Frag_T	e1;
    Frag_T	e2;
    Frag_T	e;
    nfa_state_T	*s;
    nfa_state_T	*s1;
    nfa_state_T	*matchstate;
    nfa_state_T	*ret = NULL;

    if (postfix == NULL)
	return NULL;

#define PUSH(s)	    st_push((s), &stackp, stack_end)
#define POP()	    st_pop(&stackp, stack);		\
		    if (stackp < stack)			\
		    {					\
			st_error(postfix, end, p);	\
			vim_free(stack);		\
			return NULL;			\
		    }

    if (nfa_calc_size == FALSE)
    {
	// Allocate space for the stack. Max states on the stack: "nstate".
	stack = ALLOC_MULT(Frag_T, nstate + 1);
	if (stack == NULL)
	    return NULL;
	stackp = stack;
	stack_end = stack + (nstate + 1);
    }

    for (p = postfix; p < end; ++p)
    {
	switch (*p)
	{
	case NFA_CONCAT:
	    // Concatenation.
	    // Pay attention: this operator does not exist in the r.e. itself
	    // (it is implicit, really).  It is added when r.e. is translated
	    // to postfix form in re2post().
	    if (nfa_calc_size == TRUE)
	    {
		// nstate += 0;
		break;
	    }
	    e2 = POP();
	    e1 = POP();
	    patch(e1.out, e2.start);
	    PUSH(frag(e1.start, e2.out));
	    break;

	case NFA_OR:
	    // Alternation
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    e2 = POP();
	    e1 = POP();
	    s = alloc_state(NFA_SPLIT, e1.start, e2.start);
	    if (s == NULL)
		goto theend;
	    PUSH(frag(s, append(e1.out, e2.out)));
	    break;

	case NFA_STAR:
	    // Zero or more, prefer more
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    e = POP();
	    s = alloc_state(NFA_SPLIT, e.start, NULL);
	    if (s == NULL)
		goto theend;
	    patch(e.out, s);
	    PUSH(frag(s, list1(&s->out1)));
	    break;

	case NFA_STAR_NONGREEDY:
	    // Zero or more, prefer zero
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    e = POP();
	    s = alloc_state(NFA_SPLIT, NULL, e.start);
	    if (s == NULL)
		goto theend;
	    patch(e.out, s);
	    PUSH(frag(s, list1(&s->out)));
	    break;

	case NFA_QUEST:
	    // one or zero atoms=> greedy match
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    e = POP();
	    s = alloc_state(NFA_SPLIT, e.start, NULL);
	    if (s == NULL)
		goto theend;
	    PUSH(frag(s, append(e.out, list1(&s->out1))));
	    break;

	case NFA_QUEST_NONGREEDY:
	    // zero or one atoms => non-greedy match
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    e = POP();
	    s = alloc_state(NFA_SPLIT, NULL, e.start);
	    if (s == NULL)
		goto theend;
	    PUSH(frag(s, append(e.out, list1(&s->out))));
	    break;

	case NFA_END_COLL:
	case NFA_END_NEG_COLL:
	    // On the stack is the sequence starting with NFA_START_COLL or
	    // NFA_START_NEG_COLL and all possible characters. Patch it to
	    // add the output to the start.
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    e = POP();
	    s = alloc_state(NFA_END_COLL, NULL, NULL);
	    if (s == NULL)
		goto theend;
	    patch(e.out, s);
	    e.start->out1 = s;
	    PUSH(frag(e.start, list1(&s->out)));
	    break;

	case NFA_RANGE:
	    // Before this are two characters, the low and high end of a
	    // range.  Turn them into two states with MIN and MAX.
	    if (nfa_calc_size == TRUE)
	    {
		// nstate += 0;
		break;
	    }
	    e2 = POP();
	    e1 = POP();
	    e2.start->val = e2.start->c;
	    e2.start->c = NFA_RANGE_MAX;
	    e1.start->val = e1.start->c;
	    e1.start->c = NFA_RANGE_MIN;
	    patch(e1.out, e2.start);
	    PUSH(frag(e1.start, e2.out));
	    break;

	case NFA_EMPTY:
	    // 0-length, used in a repetition with max/min count of 0
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    s = alloc_state(NFA_EMPTY, NULL, NULL);
	    if (s == NULL)
		goto theend;
	    PUSH(frag(s, list1(&s->out)));
	    break;

	case NFA_OPT_CHARS:
	  {
	    int    n;

	    // \%[abc] implemented as:
	    //    NFA_SPLIT
	    //    +-CHAR(a)
	    //    | +-NFA_SPLIT
	    //    |   +-CHAR(b)
	    //    |   | +-NFA_SPLIT
	    //    |   |   +-CHAR(c)
	    //    |   |   | +-next
	    //    |   |   +- next
	    //    |   +- next
	    //    +- next
	    n = *++p; // get number of characters
	    if (nfa_calc_size == TRUE)
	    {
		nstate += n;
		break;
	    }
	    s = NULL; // avoid compiler warning
	    e1.out = NULL; // stores list with out1's
	    s1 = NULL; // previous NFA_SPLIT to connect to
	    while (n-- > 0)
	    {
		e = POP(); // get character
		s = alloc_state(NFA_SPLIT, e.start, NULL);
		if (s == NULL)
		    goto theend;
		if (e1.out == NULL)
		    e1 = e;
		patch(e.out, s1);
		append(e1.out, list1(&s->out1));
		s1 = s;
	    }
	    PUSH(frag(s, e1.out));
	    break;
	  }

	case NFA_PREV_ATOM_NO_WIDTH:
	case NFA_PREV_ATOM_NO_WIDTH_NEG:
	case NFA_PREV_ATOM_JUST_BEFORE:
	case NFA_PREV_ATOM_JUST_BEFORE_NEG:
	case NFA_PREV_ATOM_LIKE_PATTERN:
	  {
	    int before = (*p == NFA_PREV_ATOM_JUST_BEFORE
				      || *p == NFA_PREV_ATOM_JUST_BEFORE_NEG);
	    int pattern = (*p == NFA_PREV_ATOM_LIKE_PATTERN);
	    int start_state;
	    int end_state;
	    int n = 0;
	    nfa_state_T *zend;
	    nfa_state_T *skip;

	    switch (*p)
	    {
		case NFA_PREV_ATOM_NO_WIDTH:
		    start_state = NFA_START_INVISIBLE;
		    end_state = NFA_END_INVISIBLE;
		    break;
		case NFA_PREV_ATOM_NO_WIDTH_NEG:
		    start_state = NFA_START_INVISIBLE_NEG;
		    end_state = NFA_END_INVISIBLE_NEG;
		    break;
		case NFA_PREV_ATOM_JUST_BEFORE:
		    start_state = NFA_START_INVISIBLE_BEFORE;
		    end_state = NFA_END_INVISIBLE;
		    break;
		case NFA_PREV_ATOM_JUST_BEFORE_NEG:
		    start_state = NFA_START_INVISIBLE_BEFORE_NEG;
		    end_state = NFA_END_INVISIBLE_NEG;
		    break;
		default: // NFA_PREV_ATOM_LIKE_PATTERN:
		    start_state = NFA_START_PATTERN;
		    end_state = NFA_END_PATTERN;
		    break;
	    }

	    if (before)
		n = *++p; // get the count

	    // The \@= operator: match the preceding atom with zero width.
	    // The \@! operator: no match for the preceding atom.
	    // The \@<= operator: match for the preceding atom.
	    // The \@<! operator: no match for the preceding atom.
	    // Surrounds the preceding atom with START_INVISIBLE and
	    // END_INVISIBLE, similarly to MOPEN.

	    if (nfa_calc_size == TRUE)
	    {
		nstate += pattern ? 4 : 2;
		break;
	    }
	    e = POP();
	    s1 = alloc_state(end_state, NULL, NULL);
	    if (s1 == NULL)
		goto theend;

	    s = alloc_state(start_state, e.start, s1);
	    if (s == NULL)
		goto theend;
	    if (pattern)
	    {
		// NFA_ZEND -> NFA_END_PATTERN -> NFA_SKIP -> what follows.
		skip = alloc_state(NFA_SKIP, NULL, NULL);
		if (skip == NULL)
		    goto theend;
		zend = alloc_state(NFA_ZEND, s1, NULL);
		if (zend == NULL)
		    goto theend;
		s1->out= skip;
		patch(e.out, zend);
		PUSH(frag(s, list1(&skip->out)));
	    }
	    else
	    {
		patch(e.out, s1);
		PUSH(frag(s, list1(&s1->out)));
		if (before)
		{
		    if (n <= 0)
			// See if we can guess the maximum width, it avoids a
			// lot of pointless tries.
			n = nfa_max_width(e.start, 0);
		    s->val = n; // store the count
		}
	    }
	    break;
	  }

	case NFA_COMPOSING:	// char with composing char
#if 0
	    // TODO
	    if (regflags & RF_ICOMBINE)
	    {
		// use the base character only
	    }
#endif
	    // FALLTHROUGH

	case NFA_MOPEN:	// \( \) Submatch
	case NFA_MOPEN1:
	case NFA_MOPEN2:
	case NFA_MOPEN3:
	case NFA_MOPEN4:
	case NFA_MOPEN5:
	case NFA_MOPEN6:
	case NFA_MOPEN7:
	case NFA_MOPEN8:
	case NFA_MOPEN9:
#ifdef FEAT_SYN_HL
	case NFA_ZOPEN:	// \z( \) Submatch
	case NFA_ZOPEN1:
	case NFA_ZOPEN2:
	case NFA_ZOPEN3:
	case NFA_ZOPEN4:
	case NFA_ZOPEN5:
	case NFA_ZOPEN6:
	case NFA_ZOPEN7:
	case NFA_ZOPEN8:
	case NFA_ZOPEN9:
#endif
	case NFA_NOPEN:	// \%( \) "Invisible Submatch"
	    if (nfa_calc_size == TRUE)
	    {
		nstate += 2;
		break;
	    }

	    mopen = *p;
	    switch (*p)
	    {
		case NFA_NOPEN: mclose = NFA_NCLOSE; break;
#ifdef FEAT_SYN_HL
		case NFA_ZOPEN: mclose = NFA_ZCLOSE; break;
		case NFA_ZOPEN1: mclose = NFA_ZCLOSE1; break;
		case NFA_ZOPEN2: mclose = NFA_ZCLOSE2; break;
		case NFA_ZOPEN3: mclose = NFA_ZCLOSE3; break;
		case NFA_ZOPEN4: mclose = NFA_ZCLOSE4; break;
		case NFA_ZOPEN5: mclose = NFA_ZCLOSE5; break;
		case NFA_ZOPEN6: mclose = NFA_ZCLOSE6; break;
		case NFA_ZOPEN7: mclose = NFA_ZCLOSE7; break;
		case NFA_ZOPEN8: mclose = NFA_ZCLOSE8; break;
		case NFA_ZOPEN9: mclose = NFA_ZCLOSE9; break;
#endif
		case NFA_COMPOSING: mclose = NFA_END_COMPOSING; break;
		default:
		    // NFA_MOPEN, NFA_MOPEN1 .. NFA_MOPEN9
		    mclose = *p + NSUBEXP;
		    break;
	    }

	    // Allow "NFA_MOPEN" as a valid postfix representation for
	    // the empty regexp "". In this case, the NFA will be
	    // NFA_MOPEN -> NFA_MCLOSE. Note that this also allows
	    // empty groups of parenthesis, and empty mbyte chars
	    if (stackp == stack)
	    {
		s = alloc_state(mopen, NULL, NULL);
		if (s == NULL)
		    goto theend;
		s1 = alloc_state(mclose, NULL, NULL);
		if (s1 == NULL)
		    goto theend;
		patch(list1(&s->out), s1);
		PUSH(frag(s, list1(&s1->out)));
		break;
	    }

	    // At least one node was emitted before NFA_MOPEN, so
	    // at least one node will be between NFA_MOPEN and NFA_MCLOSE
	    e = POP();
	    s = alloc_state(mopen, e.start, NULL);   // `('
	    if (s == NULL)
		goto theend;

	    s1 = alloc_state(mclose, NULL, NULL);   // `)'
	    if (s1 == NULL)
		goto theend;
	    patch(e.out, s1);

	    if (mopen == NFA_COMPOSING)
		// COMPOSING->out1 = END_COMPOSING
		patch(list1(&s->out1), s1);

	    PUSH(frag(s, list1(&s1->out)));
	    break;

	case NFA_BACKREF1:
	case NFA_BACKREF2:
	case NFA_BACKREF3:
	case NFA_BACKREF4:
	case NFA_BACKREF5:
	case NFA_BACKREF6:
	case NFA_BACKREF7:
	case NFA_BACKREF8:
	case NFA_BACKREF9:
#ifdef FEAT_SYN_HL
	case NFA_ZREF1:
	case NFA_ZREF2:
	case NFA_ZREF3:
	case NFA_ZREF4:
	case NFA_ZREF5:
	case NFA_ZREF6:
	case NFA_ZREF7:
	case NFA_ZREF8:
	case NFA_ZREF9:
#endif
	    if (nfa_calc_size == TRUE)
	    {
		nstate += 2;
		break;
	    }
	    s = alloc_state(*p, NULL, NULL);
	    if (s == NULL)
		goto theend;
	    s1 = alloc_state(NFA_SKIP, NULL, NULL);
	    if (s1 == NULL)
		goto theend;
	    patch(list1(&s->out), s1);
	    PUSH(frag(s, list1(&s1->out)));
	    break;

	case NFA_LNUM:
	case NFA_LNUM_GT:
	case NFA_LNUM_LT:
	case NFA_VCOL:
	case NFA_VCOL_GT:
	case NFA_VCOL_LT:
	case NFA_COL:
	case NFA_COL_GT:
	case NFA_COL_LT:
	case NFA_MARK:
	case NFA_MARK_GT:
	case NFA_MARK_LT:
	  {
	    int n = *++p; // lnum, col or mark name

	    if (nfa_calc_size == TRUE)
	    {
		nstate += 1;
		break;
	    }
	    s = alloc_state(p[-1], NULL, NULL);
	    if (s == NULL)
		goto theend;
	    s->val = n;
	    PUSH(frag(s, list1(&s->out)));
	    break;
	  }

	case NFA_ZSTART:
	case NFA_ZEND:
	default:
	    // Operands
	    if (nfa_calc_size == TRUE)
	    {
		nstate++;
		break;
	    }
	    s = alloc_state(*p, NULL, NULL);
	    if (s == NULL)
		goto theend;
	    PUSH(frag(s, list1(&s->out)));
	    break;

	} // switch(*p)

    } // for(p = postfix; *p; ++p)

    if (nfa_calc_size == TRUE)
    {
	nstate++;
	goto theend;	// Return value when counting size is ignored anyway
    }

    e = POP();
    if (stackp != stack)
    {
	vim_free(stack);
	EMSG_RET_NULL(_("E875: (NFA regexp) (While converting from postfix to NFA), too many states left on stack"));
    }

    if (istate >= nstate)
    {
	vim_free(stack);
	EMSG_RET_NULL(_("E876: (NFA regexp) Not enough space to store the whole NFA "));
    }

    matchstate = &state_ptr[istate++]; // the match state
    matchstate->c = NFA_MATCH;
    matchstate->out = matchstate->out1 = NULL;
    matchstate->id = 0;

    patch(e.out, matchstate);
    ret = e.start;

theend:
    vim_free(stack);
    return ret;

#undef POP1
#undef PUSH1
#undef POP2
#undef PUSH2
#undef POP
#undef PUSH
}

vim is vulnerable to Heap-based Buffer Overflow


log_subsexpr(regsubs_T *subs)
{
    log_subexpr(&subs->norm);
# ifdef FEAT_SYN_HL
    if (rex.nfa_has_zsubexpr)
	log_subexpr(&subs->synt);
# endif
}


failure_chance(nfa_state_T *state, int depth)
{
    int c = state->c;
    int l, r;

    // detect looping
    if (depth > 4)
	return 1;

    switch (c)
    {
	case NFA_SPLIT:
	    if (state->out->c == NFA_SPLIT || state->out1->c == NFA_SPLIT)
		// avoid recursive stuff
		return 1;
	    // two alternatives, use the lowest failure chance
	    l = failure_chance(state->out, depth + 1);
	    r = failure_chance(state->out1, depth + 1);
	    return l < r ? l : r;

	case NFA_ANY:
	    // matches anything, unlikely to fail
	    return 1;

	case NFA_MATCH:
	case NFA_MCLOSE:
	case NFA_ANY_COMPOSING:
	    // empty match works always
	    return 0;

	case NFA_START_INVISIBLE:
	case NFA_START_INVISIBLE_FIRST:
	case NFA_START_INVISIBLE_NEG:
	case NFA_START_INVISIBLE_NEG_FIRST:
	case NFA_START_INVISIBLE_BEFORE:
	case NFA_START_INVISIBLE_BEFORE_FIRST:
	case NFA_START_INVISIBLE_BEFORE_NEG:
	case NFA_START_INVISIBLE_BEFORE_NEG_FIRST:
	case NFA_START_PATTERN:
	    // recursive regmatch is expensive, use low failure chance
	    return 5;

	case NFA_BOL:
	case NFA_EOL:
	case NFA_BOF:
	case NFA_EOF:
	case NFA_NEWL:
	    return 99;

	case NFA_BOW:
	case NFA_EOW:
	    return 90;

	case NFA_MOPEN:
	case NFA_MOPEN1:
	case NFA_MOPEN2:
	case NFA_MOPEN3:
	case NFA_MOPEN4:
	case NFA_MOPEN5:
	case NFA_MOPEN6:
	case NFA_MOPEN7:
	case NFA_MOPEN8:
	case NFA_MOPEN9:
#ifdef FEAT_SYN_HL
	case NFA_ZOPEN:
	case NFA_ZOPEN1:
	case NFA_ZOPEN2:
	case NFA_ZOPEN3:
	case NFA_ZOPEN4:
	case NFA_ZOPEN5:
	case NFA_ZOPEN6:
	case NFA_ZOPEN7:
	case NFA_ZOPEN8:
	case NFA_ZOPEN9:
	case NFA_ZCLOSE:
	case NFA_ZCLOSE1:
	case NFA_ZCLOSE2:
	case NFA_ZCLOSE3:
	case NFA_ZCLOSE4:
	case NFA_ZCLOSE5:
	case NFA_ZCLOSE6:
	case NFA_ZCLOSE7:
	case NFA_ZCLOSE8:
	case NFA_ZCLOSE9:
#endif
	case NFA_NOPEN:
	case NFA_MCLOSE1:
	case NFA_MCLOSE2:
	case NFA_MCLOSE3:
	case NFA_MCLOSE4:
	case NFA_MCLOSE5:
	case NFA_MCLOSE6:
	case NFA_MCLOSE7:
	case NFA_MCLOSE8:
	case NFA_MCLOSE9:
	case NFA_NCLOSE:
	    return failure_chance(state->out, depth + 1);

	case NFA_BACKREF1:
	case NFA_BACKREF2:
	case NFA_BACKREF3:
	case NFA_BACKREF4:
	case NFA_BACKREF5:
	case NFA_BACKREF6:
	case NFA_BACKREF7:
	case NFA_BACKREF8:
	case NFA_BACKREF9:
#ifdef FEAT_SYN_HL
	case NFA_ZREF1:
	case NFA_ZREF2:
	case NFA_ZREF3:
	case NFA_ZREF4:
	case NFA_ZREF5:
	case NFA_ZREF6:
	case NFA_ZREF7:
	case NFA_ZREF8:
	case NFA_ZREF9:
#endif
	    // backreferences don't match in many places
	    return 94;

	case NFA_LNUM_GT:
	case NFA_LNUM_LT:
	case NFA_COL_GT:
	case NFA_COL_LT:
	case NFA_VCOL_GT:
	case NFA_VCOL_LT:
	case NFA_MARK_GT:
	case NFA_MARK_LT:
	case NFA_VISUAL:
	    // before/after positions don't match very often
	    return 85;

	case NFA_LNUM:
	    return 90;

	case NFA_CURSOR:
	case NFA_COL:
	case NFA_VCOL:
	case NFA_MARK:
	    // specific positions rarely match
	    return 98;

	case NFA_COMPOSING:
	    return 95;

	default:
	    if (c > 0)
		// character match fails often
		return 95;
    }

    // something else, includes character classes
    return 50;
}


re2post(void)
{
    if (nfa_reg(REG_NOPAREN) == FAIL)
	return NULL;
    EMIT(NFA_MOPEN);
    return post_start;
}


find_match_text(colnr_T startcol, int regstart, char_u *match_text)
{
    colnr_T col = startcol;
    int	    c1, c2;
    int	    len1, len2;
    int	    match;

    for (;;)
    {
	match = TRUE;
	len2 = MB_CHAR2LEN(regstart); // skip regstart
	for (len1 = 0; match_text[len1] != NUL; len1 += MB_CHAR2LEN(c1))
	{
	    c1 = PTR2CHAR(match_text + len1);
	    c2 = PTR2CHAR(rex.line + col + len2);
	    if (c1 != c2 && (!rex.reg_ic || MB_CASEFOLD(c1) != MB_CASEFOLD(c2)))
	    {
		match = FALSE;
		break;
	    }
	    len2 += enc_utf8 ? utf_ptr2len(rex.line + col + len2)
							     : MB_CHAR2LEN(c2);
	}
	if (match
		// check that no composing char follows
		&& !(enc_utf8
			  && utf_iscomposing(PTR2CHAR(rex.line + col + len2))))
	{
	    cleanup_subexpr();
	    if (REG_MULTI)
	    {
		rex.reg_startpos[0].lnum = rex.lnum;
		rex.reg_startpos[0].col = col;
		rex.reg_endpos[0].lnum = rex.lnum;
		rex.reg_endpos[0].col = col + len2;
	    }
	    else
	    {
		rex.reg_startp[0] = rex.line + col;
		rex.reg_endp[0] = rex.line + col + len2;
	    }
	    return 1L;
	}

	// Try finding regstart after the current match.
	col += MB_CHAR2LEN(regstart); // skip regstart
	if (skip_to_start(regstart, &col) == FAIL)
	    break;
    }
    return 0L;
}


realloc_post_list(void)
{
    int   nstate_max = (int)(post_end - post_start);
    int   new_max;
    int   *new_start;
    int	  *old_start;

    // For weird patterns the number of states can be very high. Increasing by
    // 50% seems a reasonable compromise between memory use and speed.
    new_max = nstate_max * 3 / 2;
    new_start = ALLOC_MULT(int, new_max);
    if (new_start == NULL)
	return FAIL;
    mch_memmove(new_start, post_start, nstate_max * sizeof(int));
    old_start = post_start;
    post_start = new_start;
    post_ptr = new_start + (post_ptr - old_start);
    post_end = post_start + new_max;
    vim_free(old_start);
    return OK;
}


nfa_reg(
    int		paren)	// REG_NOPAREN, REG_PAREN, REG_NPAREN or REG_ZPAREN
{
    int		parno = 0;

    if (paren == REG_PAREN)
    {
	if (regnpar >= NSUBEXP) // Too many `('
	    EMSG_RET_FAIL(_("E872: (NFA regexp) Too many '('"));
	parno = regnpar++;
    }
#ifdef FEAT_SYN_HL
    else if (paren == REG_ZPAREN)
    {
	// Make a ZOPEN node.
	if (regnzpar >= NSUBEXP)
	    EMSG_RET_FAIL(_("E879: (NFA regexp) Too many \\z("));
	parno = regnzpar++;
    }
#endif

    if (nfa_regbranch() == FAIL)
	return FAIL;	    // cascaded error

    while (peekchr() == Magic('|'))
    {
	skipchr();
	if (nfa_regbranch() == FAIL)
	    return FAIL;    // cascaded error
	EMIT(NFA_OR);
    }

    // Check for proper termination.
    if (paren != REG_NOPAREN && getchr() != Magic(')'))
    {
	if (paren == REG_NPAREN)
	    EMSG2_RET_FAIL(_(e_unmatched_str_percent_open),
						       reg_magic == MAGIC_ALL);
	else
	    EMSG2_RET_FAIL(_(e_unmatched_str_open), reg_magic == MAGIC_ALL);
    }
    else if (paren == REG_NOPAREN && peekchr() != NUL)
    {
	if (peekchr() == Magic(')'))
	    EMSG2_RET_FAIL(_(e_unmatched_str_close), reg_magic == MAGIC_ALL);
	else
	    EMSG_RET_FAIL(_("E873: (NFA regexp) proper termination error"));
    }
    /*
     * Here we set the flag allowing back references to this set of
     * parentheses.
     */
    if (paren == REG_PAREN)
    {
	had_endbrace[parno] = TRUE;     // have seen the close paren
	EMIT(NFA_MOPEN + parno);
    }
#ifdef FEAT_SYN_HL
    else if (paren == REG_ZPAREN)
	EMIT(NFA_ZOPEN + parno);
#endif

    return OK;
}


nfa_regbranch(void)
{
    int		old_post_pos;

    old_post_pos = (int)(post_ptr - post_start);

    // First branch, possibly the only one
    if (nfa_regconcat() == FAIL)
	return FAIL;

    // Try next concats
    while (peekchr() == Magic('&'))
    {
	skipchr();
	// if concat is empty do emit a node
	if (old_post_pos == (int)(post_ptr - post_start))
	    EMIT(NFA_EMPTY);
	EMIT(NFA_NOPEN);
	EMIT(NFA_PREV_ATOM_NO_WIDTH);
	old_post_pos = (int)(post_ptr - post_start);
	if (nfa_regconcat() == FAIL)
	    return FAIL;
	// if concat is empty do emit a node
	if (old_post_pos == (int)(post_ptr - post_start))
	    EMIT(NFA_EMPTY);
	EMIT(NFA_CONCAT);
    }

    // if a branch is empty, emit one node for it
    if (old_post_pos == (int)(post_ptr - post_start))
	EMIT(NFA_EMPTY);

    return OK;
}


check_char_class(int class, int c)
{
    switch (class)
    {
	case NFA_CLASS_ALNUM:
	    if (c >= 1 && c < 128 && isalnum(c))
		return OK;
	    break;
	case NFA_CLASS_ALPHA:
	    if (c >= 1 && c < 128 && isalpha(c))
		return OK;
	    break;
	case NFA_CLASS_BLANK:
	    if (c == ' ' || c == '\t')
		return OK;
	    break;
	case NFA_CLASS_CNTRL:
	    if (c >= 1 && c <= 127 && iscntrl(c))
		return OK;
	    break;
	case NFA_CLASS_DIGIT:
	    if (VIM_ISDIGIT(c))
		return OK;
	    break;
	case NFA_CLASS_GRAPH:
	    if (c >= 1 && c <= 127 && isgraph(c))
		return OK;
	    break;
	case NFA_CLASS_LOWER:
	    if (MB_ISLOWER(c) && c != 170 && c != 186)
		return OK;
	    break;
	case NFA_CLASS_PRINT:
	    if (vim_isprintc(c))
		return OK;
	    break;
	case NFA_CLASS_PUNCT:
	    if (c >= 1 && c < 128 && ispunct(c))
		return OK;
	    break;
	case NFA_CLASS_SPACE:
	    if ((c >= 9 && c <= 13) || (c == ' '))
		return OK;
	    break;
	case NFA_CLASS_UPPER:
	    if (MB_ISUPPER(c))
		return OK;
	    break;
	case NFA_CLASS_XDIGIT:
	    if (vim_isxdigit(c))
		return OK;
	    break;
	case NFA_CLASS_TAB:
	    if (c == '\t')
		return OK;
	    break;
	case NFA_CLASS_RETURN:
	    if (c == '\r')
		return OK;
	    break;
	case NFA_CLASS_BACKSPACE:
	    if (c == '\b')
		return OK;
	    break;
	case NFA_CLASS_ESCAPE:
	    if (c == '\033')
		return OK;
	    break;
	case NFA_CLASS_IDENT:
	    if (vim_isIDc(c))
		return OK;
	    break;
	case NFA_CLASS_KEYWORD:
	    if (reg_iswordc(c))
		return OK;
	    break;
	case NFA_CLASS_FNAME:
	    if (vim_isfilec(c))
		return OK;
	    break;

	default:
	    // should not be here :P
	    siemsg(_(e_ill_char_class), class);
	    return FAIL;
    }
    return FAIL;
}


nfa_print_state2(FILE *debugf, nfa_state_T *state, garray_T *indent)
{
    char_u  *p;

    if (state == NULL)
	return;

    fprintf(debugf, "(%2d)", abs(state->id));

    // Output indent
    p = (char_u *)indent->ga_data;
    if (indent->ga_len >= 3)
    {
	int	last = indent->ga_len - 3;
	char_u	save[2];

	STRNCPY(save, &p[last], 2);
	STRNCPY(&p[last], "+-", 2);
	fprintf(debugf, " %s", p);
	STRNCPY(&p[last], save, 2);
    }
    else
	fprintf(debugf, " %s", p);

    nfa_set_code(state->c);
    fprintf(debugf, "%s (%d) (id=%d) val=%d\n",
		 code,
		 state->c,
		 abs(state->id),
		 state->val);
    if (state->id < 0)
	return;

    state->id = abs(state->id) * -1;

    // grow indent for state->out
    indent->ga_len -= 1;
    if (state->out1)
	ga_concat(indent, (char_u *)"| ");
    else
	ga_concat(indent, (char_u *)"  ");
    ga_append(indent, '\0');

    nfa_print_state2(debugf, state->out, indent);

    // replace last part of indent for state->out1
    indent->ga_len -= 3;
    ga_concat(indent, (char_u *)"  ");
    ga_append(indent, '\0');

    nfa_print_state2(debugf, state->out1, indent);

    // shrink indent
    indent->ga_len -= 3;
    ga_append(indent, '\0');
}


nfa_regexec_both(
    char_u	*line,
    colnr_T	startcol,	// column to start looking for match
    proftime_T	*tm,		// timeout limit or NULL
    int		*timed_out)	// flag set on timeout or NULL
{
    nfa_regprog_T   *prog;
    long	    retval = 0L;
    int		    i;
    colnr_T	    col = startcol;

    if (REG_MULTI)
    {
	prog = (nfa_regprog_T *)rex.reg_mmatch->regprog;
	line = reg_getline((linenr_T)0);    // relative to the cursor
	rex.reg_startpos = rex.reg_mmatch->startpos;
	rex.reg_endpos = rex.reg_mmatch->endpos;
    }
    else
    {
	prog = (nfa_regprog_T *)rex.reg_match->regprog;
	rex.reg_startp = rex.reg_match->startp;
	rex.reg_endp = rex.reg_match->endp;
    }

    // Be paranoid...
    if (prog == NULL || line == NULL)
    {
	iemsg(_(e_null_argument));
	goto theend;
    }

    // If pattern contains "\c" or "\C": overrule value of rex.reg_ic
    if (prog->regflags & RF_ICASE)
	rex.reg_ic = TRUE;
    else if (prog->regflags & RF_NOICASE)
	rex.reg_ic = FALSE;

    // If pattern contains "\Z" overrule value of rex.reg_icombine
    if (prog->regflags & RF_ICOMBINE)
	rex.reg_icombine = TRUE;

    rex.line = line;
    rex.lnum = 0;    // relative to line

    rex.nfa_has_zend = prog->has_zend;
    rex.nfa_has_backref = prog->has_backref;
    rex.nfa_nsubexpr = prog->nsubexp;
    rex.nfa_listid = 1;
    rex.nfa_alt_listid = 2;
#ifdef DEBUG
    nfa_regengine.expr = prog->pattern;
#endif

    if (prog->reganch && col > 0)
	return 0L;

    rex.need_clear_subexpr = TRUE;
#ifdef FEAT_SYN_HL
    // Clear the external match subpointers if necessary.
    if (prog->reghasz == REX_SET)
    {
	rex.nfa_has_zsubexpr = TRUE;
	rex.need_clear_zsubexpr = TRUE;
    }
    else
    {
	rex.nfa_has_zsubexpr = FALSE;
	rex.need_clear_zsubexpr = FALSE;
    }
#endif

    if (prog->regstart != NUL)
    {
	// Skip ahead until a character we know the match must start with.
	// When there is none there is no match.
	if (skip_to_start(prog->regstart, &col) == FAIL)
	    return 0L;

	// If match_text is set it contains the full text that must match.
	// Nothing else to try. Doesn't handle combining chars well.
	if (prog->match_text != NULL && !rex.reg_icombine)
	    return find_match_text(col, prog->regstart, prog->match_text);
    }

    // If the start column is past the maximum column: no need to try.
    if (rex.reg_maxcol > 0 && col >= rex.reg_maxcol)
	goto theend;

    // Set the "nstate" used by nfa_regcomp() to zero to trigger an error when
    // it's accidentally used during execution.
    nstate = 0;
    for (i = 0; i < prog->nstate; ++i)
    {
	prog->state[i].id = i;
	prog->state[i].lastlist[0] = 0;
	prog->state[i].lastlist[1] = 0;
    }

    retval = nfa_regtry(prog, col, tm, timed_out);

#ifdef DEBUG
    nfa_regengine.expr = NULL;
#endif

theend:
    if (retval > 0)
    {
	// Make sure the end is never before the start.  Can happen when \zs and
	// \ze are used.
	if (REG_MULTI)
	{
	    lpos_T *start = &rex.reg_mmatch->startpos[0];
	    lpos_T *end = &rex.reg_mmatch->endpos[0];

	    if (end->lnum < start->lnum
			|| (end->lnum == start->lnum && end->col < start->col))
		rex.reg_mmatch->endpos[0] = rex.reg_mmatch->startpos[0];
	}
	else
	{
	    if (rex.reg_match->endp[0] < rex.reg_match->startp[0])
		rex.reg_match->endp[0] = rex.reg_match->startp[0];
	}
    }

    return retval;
}


nfa_regexec_nl(
    regmatch_T	*rmp,
    char_u	*line,	// string to match against
    colnr_T	col,	// column to start looking for match
    int		line_lbr)
{
    rex.reg_match = rmp;
    rex.reg_mmatch = NULL;
    rex.reg_maxline = 0;
    rex.reg_line_lbr = line_lbr;
    rex.reg_buf = curbuf;
    rex.reg_win = NULL;
    rex.reg_ic = rmp->rm_ic;
    rex.reg_icombine = FALSE;
    rex.reg_maxcol = 0;
    return nfa_regexec_both(line, col, NULL, NULL);
}


nfa_print_state(FILE *debugf, nfa_state_T *state)
{
    garray_T indent;

    ga_init2(&indent, 1, 64);
    ga_append(&indent, '\0');
    nfa_print_state2(debugf, state, &indent);
    ga_clear(&indent);
}


nfa_get_match_text(nfa_state_T *start)
{
    nfa_state_T *p = start;
    int		len = 0;
    char_u	*ret;
    char_u	*s;

    if (p->c != NFA_MOPEN)
	return NULL; // just in case
    p = p->out;
    while (p->c > 0)
    {
	len += MB_CHAR2LEN(p->c);
	p = p->out;
    }
    if (p->c != NFA_MCLOSE || p->out->c != NFA_MATCH)
	return NULL;

    ret = alloc(len);
    if (ret != NULL)
    {
	p = start->out->out; // skip first char, it goes into regstart
	s = ret;
	while (p->c > 0)
	{
	    if (has_mbyte)
		s += (*mb_char2bytes)(p->c, s);
	    else
		*s++ = p->c;
	    p = p->out;
	}
	*s = NUL;
    }
    return ret;
}


pim_equal(nfa_pim_T *one, nfa_pim_T *two)
{
    int one_unused = (one == NULL || one->result == NFA_PIM_UNUSED);
    int two_unused = (two == NULL || two->result == NFA_PIM_UNUSED);

    if (one_unused)
	// one is unused: equal when two is also unused
	return two_unused;
    if (two_unused)
	// one is used and two is not: not equal
	return FALSE;
    // compare the state id
    if (one->state->id != two->state->id)
	return FALSE;
    // compare the position
    if (REG_MULTI)
	return one->end.pos.lnum == two->end.pos.lnum
	    && one->end.pos.col == two->end.pos.col;
    return one->end.ptr == two->end.ptr;
}


st_pop(Frag_T **p, Frag_T *stack)
{
    Frag_T *stackp;

    *p = *p - 1;
    stackp = *p;
    if (stackp < stack)
	return empty;
    return **p;
}


state_in_list(
    nfa_list_T		*l,	// runtime state list
    nfa_state_T		*state,	// state to update
    regsubs_T		*subs)	// pointers to subexpressions
{
    if (state->lastlist[nfa_ll_index] == l->id)
    {
	if (!rex.nfa_has_backref || has_state_with_pos(l, state, subs, NULL))
	    return TRUE;
    }
    return FALSE;
}


sub_equal(regsub_T *sub1, regsub_T *sub2)
{
    int		i;
    int		todo;
    linenr_T	s1;
    linenr_T	s2;
    char_u	*sp1;
    char_u	*sp2;

    todo = sub1->in_use > sub2->in_use ? sub1->in_use : sub2->in_use;
    if (REG_MULTI)
    {
	for (i = 0; i < todo; ++i)
	{
	    if (i < sub1->in_use)
		s1 = sub1->list.multi[i].start_lnum;
	    else
		s1 = -1;
	    if (i < sub2->in_use)
		s2 = sub2->list.multi[i].start_lnum;
	    else
		s2 = -1;
	    if (s1 != s2)
		return FALSE;
	    if (s1 != -1 && sub1->list.multi[i].start_col
					     != sub2->list.multi[i].start_col)
		return FALSE;

	    if (rex.nfa_has_backref)
	    {
		if (i < sub1->in_use)
		    s1 = sub1->list.multi[i].end_lnum;
		else
		    s1 = -1;
		if (i < sub2->in_use)
		    s2 = sub2->list.multi[i].end_lnum;
		else
		    s2 = -1;
		if (s1 != s2)
		    return FALSE;
		if (s1 != -1 && sub1->list.multi[i].end_col
					       != sub2->list.multi[i].end_col)
		return FALSE;
	    }
	}
    }
    else
    {
	for (i = 0; i < todo; ++i)
	{
	    if (i < sub1->in_use)
		sp1 = sub1->list.line[i].start;
	    else
		sp1 = NULL;
	    if (i < sub2->in_use)
		sp2 = sub2->list.line[i].start;
	    else
		sp2 = NULL;
	    if (sp1 != sp2)
		return FALSE;
	    if (rex.nfa_has_backref)
	    {
		if (i < sub1->in_use)
		    sp1 = sub1->list.line[i].end;
		else
		    sp1 = NULL;
		if (i < sub2->in_use)
		    sp2 = sub2->list.line[i].end;
		else
		    sp2 = NULL;
		if (sp1 != sp2)
		    return FALSE;
	    }
	}
    }

    return TRUE;
}


nfa_get_reganch(nfa_state_T *start, int depth)
{
    nfa_state_T *p = start;

    if (depth > 4)
	return 0;

    while (p != NULL)
    {
	switch (p->c)
	{
	    case NFA_BOL:
	    case NFA_BOF:
		return 1; // yes!

	    case NFA_ZSTART:
	    case NFA_ZEND:
	    case NFA_CURSOR:
	    case NFA_VISUAL:

	    case NFA_MOPEN:
	    case NFA_MOPEN1:
	    case NFA_MOPEN2:
	    case NFA_MOPEN3:
	    case NFA_MOPEN4:
	    case NFA_MOPEN5:
	    case NFA_MOPEN6:
	    case NFA_MOPEN7:
	    case NFA_MOPEN8:
	    case NFA_MOPEN9:
	    case NFA_NOPEN:
#ifdef FEAT_SYN_HL
	    case NFA_ZOPEN:
	    case NFA_ZOPEN1:
	    case NFA_ZOPEN2:
	    case NFA_ZOPEN3:
	    case NFA_ZOPEN4:
	    case NFA_ZOPEN5:
	    case NFA_ZOPEN6:
	    case NFA_ZOPEN7:
	    case NFA_ZOPEN8:
	    case NFA_ZOPEN9:
#endif
		p = p->out;
		break;

	    case NFA_SPLIT:
		return nfa_get_reganch(p->out, depth + 1)
				       && nfa_get_reganch(p->out1, depth + 1);

	    default:
		return 0; // noooo
	}
    }
    return 0;
}


nfa_max_width(nfa_state_T *startstate, int depth)
{
    int		    l, r;
    nfa_state_T	    *state = startstate;
    int		    len = 0;

    // detect looping in a NFA_SPLIT
    if (depth > 4)
	return -1;

    while (state != NULL)
    {
	switch (state->c)
	{
	    case NFA_END_INVISIBLE:
	    case NFA_END_INVISIBLE_NEG:
		// the end, return what we have
		return len;

	    case NFA_SPLIT:
		// two alternatives, use the maximum
		l = nfa_max_width(state->out, depth + 1);
		r = nfa_max_width(state->out1, depth + 1);
		if (l < 0 || r < 0)
		    return -1;
		return len + (l > r ? l : r);

	    case NFA_ANY:
	    case NFA_START_COLL:
	    case NFA_START_NEG_COLL:
		// matches some character, including composing chars
		if (enc_utf8)
		    len += MB_MAXBYTES;
		else if (has_mbyte)
		    len += 2;
		else
		    ++len;
		if (state->c != NFA_ANY)
		{
		    // skip over the characters
		    state = state->out1->out;
		    continue;
		}
		break;

	    case NFA_DIGIT:
	    case NFA_WHITE:
	    case NFA_HEX:
	    case NFA_OCTAL:
		// ascii
		++len;
		break;

	    case NFA_IDENT:
	    case NFA_SIDENT:
	    case NFA_KWORD:
	    case NFA_SKWORD:
	    case NFA_FNAME:
	    case NFA_SFNAME:
	    case NFA_PRINT:
	    case NFA_SPRINT:
	    case NFA_NWHITE:
	    case NFA_NDIGIT:
	    case NFA_NHEX:
	    case NFA_NOCTAL:
	    case NFA_WORD:
	    case NFA_NWORD:
	    case NFA_HEAD:
	    case NFA_NHEAD:
	    case NFA_ALPHA:
	    case NFA_NALPHA:
	    case NFA_LOWER:
	    case NFA_NLOWER:
	    case NFA_UPPER:
	    case NFA_NUPPER:
	    case NFA_LOWER_IC:
	    case NFA_NLOWER_IC:
	    case NFA_UPPER_IC:
	    case NFA_NUPPER_IC:
	    case NFA_ANY_COMPOSING:
		// possibly non-ascii
		if (has_mbyte)
		    len += 3;
		else
		    ++len;
		break;

	    case NFA_START_INVISIBLE:
	    case NFA_START_INVISIBLE_NEG:
	    case NFA_START_INVISIBLE_BEFORE:
	    case NFA_START_INVISIBLE_BEFORE_NEG:
		// zero-width, out1 points to the END state
		state = state->out1->out;
		continue;

	    case NFA_BACKREF1:
	    case NFA_BACKREF2:
	    case NFA_BACKREF3:
	    case NFA_BACKREF4:
	    case NFA_BACKREF5:
	    case NFA_BACKREF6:
	    case NFA_BACKREF7:
	    case NFA_BACKREF8:
	    case NFA_BACKREF9:
#ifdef FEAT_SYN_HL
	    case NFA_ZREF1:
	    case NFA_ZREF2:
	    case NFA_ZREF3:
	    case NFA_ZREF4:
	    case NFA_ZREF5:
	    case NFA_ZREF6:
	    case NFA_ZREF7:
	    case NFA_ZREF8:
	    case NFA_ZREF9:
#endif
	    case NFA_NEWL:
	    case NFA_SKIP:
		// unknown width
		return -1;

	    case NFA_BOL:
	    case NFA_EOL:
	    case NFA_BOF:
	    case NFA_EOF:
	    case NFA_BOW:
	    case NFA_EOW:
	    case NFA_MOPEN:
	    case NFA_MOPEN1:
	    case NFA_MOPEN2:
	    case NFA_MOPEN3:
	    case NFA_MOPEN4:
	    case NFA_MOPEN5:
	    case NFA_MOPEN6:
	    case NFA_MOPEN7:
	    case NFA_MOPEN8:
	    case NFA_MOPEN9:
#ifdef FEAT_SYN_HL
	    case NFA_ZOPEN:
	    case NFA_ZOPEN1:
	    case NFA_ZOPEN2:
	    case NFA_ZOPEN3:
	    case NFA_ZOPEN4:
	    case NFA_ZOPEN5:
	    case NFA_ZOPEN6:
	    case NFA_ZOPEN7:
	    case NFA_ZOPEN8:
	    case NFA_ZOPEN9:
	    case NFA_ZCLOSE:
	    case NFA_ZCLOSE1:
	    case NFA_ZCLOSE2:
	    case NFA_ZCLOSE3:
	    case NFA_ZCLOSE4:
	    case NFA_ZCLOSE5:
	    case NFA_ZCLOSE6:
	    case NFA_ZCLOSE7:
	    case NFA_ZCLOSE8:
	    case NFA_ZCLOSE9:
#endif
	    case NFA_MCLOSE:
	    case NFA_MCLOSE1:
	    case NFA_MCLOSE2:
	    case NFA_MCLOSE3:
	    case NFA_MCLOSE4:
	    case NFA_MCLOSE5:
	    case NFA_MCLOSE6:
	    case NFA_MCLOSE7:
	    case NFA_MCLOSE8:
	    case NFA_MCLOSE9:
	    case NFA_NOPEN:
	    case NFA_NCLOSE:

	    case NFA_LNUM_GT:
	    case NFA_LNUM_LT:
	    case NFA_COL_GT:
	    case NFA_COL_LT:
	    case NFA_VCOL_GT:
	    case NFA_VCOL_LT:
	    case NFA_MARK_GT:
	    case NFA_MARK_LT:
	    case NFA_VISUAL:
	    case NFA_LNUM:
	    case NFA_CURSOR:
	    case NFA_COL:
	    case NFA_VCOL:
	    case NFA_MARK:

	    case NFA_ZSTART:
	    case NFA_ZEND:
	    case NFA_OPT_CHARS:
	    case NFA_EMPTY:
	    case NFA_START_PATTERN:
	    case NFA_END_PATTERN:
	    case NFA_COMPOSING:
	    case NFA_END_COMPOSING:
		// zero-width
		break;

	    default:
		if (state->c < 0)
		    // don't know what this is
		    return -1;
		// normal character
		len += MB_CHAR2LEN(state->c);
		break;
	}

	// normal way to continue
	state = state->out;
    }

    // unrecognized, "cannot happen"
    return -1;
}


nfa_recognize_char_class(char_u *start, char_u *end, int extra_newl)
{
#   define CLASS_not		0x80
#   define CLASS_af		0x40
#   define CLASS_AF		0x20
#   define CLASS_az		0x10
#   define CLASS_AZ		0x08
#   define CLASS_o7		0x04
#   define CLASS_o9		0x02
#   define CLASS_underscore	0x01

    int		newl = FALSE;
    char_u	*p;
    int		config = 0;

    if (extra_newl == TRUE)
	newl = TRUE;

    if (*end != ']')
	return FAIL;
    p = start;
    if (*p == '^')
    {
	config |= CLASS_not;
	p++;
    }

    while (p < end)
    {
	if (p + 2 < end && *(p + 1) == '-')
	{
	    switch (*p)
	    {
		case '0':
		    if (*(p + 2) == '9')
		    {
			config |= CLASS_o9;
			break;
		    }
		    if (*(p + 2) == '7')
		    {
			config |= CLASS_o7;
			break;
		    }
		    return FAIL;

		case 'a':
		    if (*(p + 2) == 'z')
		    {
			config |= CLASS_az;
			break;
		    }
		    if (*(p + 2) == 'f')
		    {
			config |= CLASS_af;
			break;
		    }
		    return FAIL;

		case 'A':
		    if (*(p + 2) == 'Z')
		    {
			config |= CLASS_AZ;
			break;
		    }
		    if (*(p + 2) == 'F')
		    {
			config |= CLASS_AF;
			break;
		    }
		    return FAIL;

		default:
		    return FAIL;
	    }
	    p += 3;
	}
	else if (p + 1 < end && *p == '\\' && *(p + 1) == 'n')
	{
	    newl = TRUE;
	    p += 2;
	}
	else if (*p == '_')
	{
	    config |= CLASS_underscore;
	    p ++;
	}
	else if (*p == '\n')
	{
	    newl = TRUE;
	    p ++;
	}
	else
	    return FAIL;
    } // while (p < end)

    if (p != end)
	return FAIL;

    if (newl == TRUE)
	extra_newl = NFA_ADD_NL;

    switch (config)
    {
	case CLASS_o9:
	    return extra_newl + NFA_DIGIT;
	case CLASS_not |  CLASS_o9:
	    return extra_newl + NFA_NDIGIT;
	case CLASS_af | CLASS_AF | CLASS_o9:
	    return extra_newl + NFA_HEX;
	case CLASS_not | CLASS_af | CLASS_AF | CLASS_o9:
	    return extra_newl + NFA_NHEX;
	case CLASS_o7:
	    return extra_newl + NFA_OCTAL;
	case CLASS_not | CLASS_o7:
	    return extra_newl + NFA_NOCTAL;
	case CLASS_az | CLASS_AZ | CLASS_o9 | CLASS_underscore:
	    return extra_newl + NFA_WORD;
	case CLASS_not | CLASS_az | CLASS_AZ | CLASS_o9 | CLASS_underscore:
	    return extra_newl + NFA_NWORD;
	case CLASS_az | CLASS_AZ | CLASS_underscore:
	    return extra_newl + NFA_HEAD;
	case CLASS_not | CLASS_az | CLASS_AZ | CLASS_underscore:
	    return extra_newl + NFA_NHEAD;
	case CLASS_az | CLASS_AZ:
	    return extra_newl + NFA_ALPHA;
	case CLASS_not | CLASS_az | CLASS_AZ:
	    return extra_newl + NFA_NALPHA;
	case CLASS_az:
	   return extra_newl + NFA_LOWER_IC;
	case CLASS_not | CLASS_az:
	    return extra_newl + NFA_NLOWER_IC;
	case CLASS_AZ:
	    return extra_newl + NFA_UPPER_IC;
	case CLASS_not | CLASS_AZ:
	    return extra_newl + NFA_NUPPER_IC;
    }
    return FAIL;
}


nfa_save_listids(nfa_regprog_T *prog, int *list)
{
    int		    i;
    nfa_state_T	    *p;

    // Order in the list is reverse, it's a bit faster that way.
    p = &prog->state[0];
    for (i = prog->nstate; --i >= 0; )
    {
	list[i] = p->lastlist[1];
	p->lastlist[1] = 0;
	++p;
    }
}


addstate_here(
    nfa_list_T		*l,	// runtime state list
    nfa_state_T		*state,	// state to update
    regsubs_T		*subs,	// pointers to subexpressions
    nfa_pim_T		*pim,   // postponed look-behind match
    int			*ip)
{
    int tlen = l->n;
    int count;
    int listidx = *ip;
    regsubs_T *r;

    // First add the state(s) at the end, so that we know how many there are.
    // Pass the listidx as offset (avoids adding another argument to
    // addstate().
    r = addstate(l, state, subs, pim, -listidx - ADDSTATE_HERE_OFFSET);
    if (r == NULL)
	return NULL;

    // when "*ip" was at the end of the list, nothing to do
    if (listidx + 1 == tlen)
	return r;

    // re-order to put the new state at the current position
    count = l->n - tlen;
    if (count == 0)
	return r; // no state got added
    if (count == 1)
    {
	// overwrite the current state
	l->t[listidx] = l->t[l->n - 1];
    }
    else if (count > 1)
    {
	if (l->n + count - 1 >= l->len)
	{
	    // not enough space to move the new states, reallocate the list
	    // and move the states to the right position
	    int		    newlen = l->len * 3 / 2 + 50;
	    size_t	    newsize = newlen * sizeof(nfa_thread_T);
	    nfa_thread_T    *newl;

	    if ((long)(newsize >> 10) >= p_mmp)
	    {
		emsg(_(e_maxmempat));
		return NULL;
	    }
	    newl = alloc(newsize);
	    if (newl == NULL)
		return NULL;
	    l->len = newlen;
	    mch_memmove(&(newl[0]),
		    &(l->t[0]),
		    sizeof(nfa_thread_T) * listidx);
	    mch_memmove(&(newl[listidx]),
		    &(l->t[l->n - count]),
		    sizeof(nfa_thread_T) * count);
	    mch_memmove(&(newl[listidx + count]),
		    &(l->t[listidx + 1]),
		    sizeof(nfa_thread_T) * (l->n - count - listidx - 1));
	    vim_free(l->t);
	    l->t = newl;
	}
	else
	{
	    // make space for new states, then move them from the
	    // end to the current position
	    mch_memmove(&(l->t[listidx + count]),
		    &(l->t[listidx + 1]),
		    sizeof(nfa_thread_T) * (l->n - listidx - 1));
	    mch_memmove(&(l->t[listidx]),
		    &(l->t[l->n - 1]),
		    sizeof(nfa_thread_T) * count);
	}
    }
    --l->n;
    *ip = listidx - 1;

    return r;
}


nfa_emit_equi_class(int c)
{
#define EMIT2(c)    EMIT(c); EMIT(NFA_CONCAT);

    if (enc_utf8 || STRCMP(p_enc, "latin1") == 0
					 || STRCMP(p_enc, "iso-8859-15") == 0)
    {
#ifdef EBCDIC
# define A_circumflex 0x62
# define A_diaeresis 0x63
# define A_grave 0x64
# define A_acute 0x65
# define A_virguilla 0x66
# define A_ring 0x67
# define C_cedilla 0x68
# define E_acute 0x71
# define E_circumflex 0x72
# define E_diaeresis 0x73
# define E_grave 0x74
# define I_acute 0x75
# define I_circumflex 0x76
# define I_diaeresis 0x77
# define I_grave 0x78
# define N_virguilla 0x69
# define O_circumflex 0xeb
# define O_diaeresis 0xec
# define O_grave 0xed
# define O_acute 0xee
# define O_virguilla 0xef
# define O_slash 0x80
# define U_circumflex 0xfb
# define U_diaeresis 0xfc
# define U_grave 0xfd
# define U_acute 0xfe
# define Y_acute 0xba
# define a_grave 0x42
# define a_acute 0x43
# define a_circumflex 0x44
# define a_virguilla 0x45
# define a_diaeresis 0x46
# define a_ring 0x47
# define c_cedilla 0x48
# define e_grave 0x51
# define e_acute 0x52
# define e_circumflex 0x53
# define e_diaeresis 0x54
# define i_grave 0x55
# define i_acute 0x56
# define i_circumflex 0x57
# define i_diaeresis 0x58
# define n_virguilla 0x49
# define o_grave 0xcb
# define o_acute 0xcc
# define o_circumflex 0xcd
# define o_virguilla 0xce
# define o_diaeresis 0xcf
# define o_slash 0x70
# define u_grave 0xdb
# define u_acute 0xdc
# define u_circumflex 0xdd
# define u_diaeresis 0xde
# define y_acute 0x8d
# define y_diaeresis 0xdf
#else
# define A_grave 0xc0
# define A_acute 0xc1
# define A_circumflex 0xc2
# define A_virguilla 0xc3
# define A_diaeresis 0xc4
# define A_ring 0xc5
# define C_cedilla 0xc7
# define E_grave 0xc8
# define E_acute 0xc9
# define E_circumflex 0xca
# define E_diaeresis 0xcb
# define I_grave 0xcc
# define I_acute 0xcd
# define I_circumflex 0xce
# define I_diaeresis 0xcf
# define N_virguilla 0xd1
# define O_grave 0xd2
# define O_acute 0xd3
# define O_circumflex 0xd4
# define O_virguilla 0xd5
# define O_diaeresis 0xd6
# define O_slash 0xd8
# define U_grave 0xd9
# define U_acute 0xda
# define U_circumflex 0xdb
# define U_diaeresis 0xdc
# define Y_acute 0xdd
# define a_grave 0xe0
# define a_acute 0xe1
# define a_circumflex 0xe2
# define a_virguilla 0xe3
# define a_diaeresis 0xe4
# define a_ring 0xe5
# define c_cedilla 0xe7
# define e_grave 0xe8
# define e_acute 0xe9
# define e_circumflex 0xea
# define e_diaeresis 0xeb
# define i_grave 0xec
# define i_acute 0xed
# define i_circumflex 0xee
# define i_diaeresis 0xef
# define n_virguilla 0xf1
# define o_grave 0xf2
# define o_acute 0xf3
# define o_circumflex 0xf4
# define o_virguilla 0xf5
# define o_diaeresis 0xf6
# define o_slash 0xf8
# define u_grave 0xf9
# define u_acute 0xfa
# define u_circumflex 0xfb
# define u_diaeresis 0xfc
# define y_acute 0xfd
# define y_diaeresis 0xff
#endif
	switch (c)
	{
	    case 'A': case A_grave: case A_acute: case A_circumflex:
	    case A_virguilla: case A_diaeresis: case A_ring:
	    case 0x100: case 0x102: case 0x104: case 0x1cd:
	    case 0x1de: case 0x1e0: case 0x1fa: case 0x200:
	    case 0x202: case 0x226: case 0x23a: case 0x1e00:
	    case 0x1ea0: case 0x1ea2: case 0x1ea4: case 0x1ea6:
	    case 0x1ea8: case 0x1eaa: case 0x1eac: case 0x1eae:
	    case 0x1eb0: case 0x1eb2: case 0x1eb4: case 0x1eb6:
		    EMIT2('A') EMIT2(A_grave) EMIT2(A_acute)
		    EMIT2(A_circumflex) EMIT2(A_virguilla)
		    EMIT2(A_diaeresis) EMIT2(A_ring)
		    EMIT2(0x100) EMIT2(0x102) EMIT2(0x104)
		    EMIT2(0x1cd) EMIT2(0x1de) EMIT2(0x1e0)
		    EMIT2(0x1fa) EMIT2(0x200) EMIT2(0x202)
		    EMIT2(0x226) EMIT2(0x23a) EMIT2(0x1e00)
		    EMIT2(0x1ea0) EMIT2(0x1ea2) EMIT2(0x1ea4)
		    EMIT2(0x1ea6) EMIT2(0x1ea8) EMIT2(0x1eaa)
		    EMIT2(0x1eac) EMIT2(0x1eae) EMIT2(0x1eb0)
		    EMIT2(0x1eb2) EMIT2(0x1eb6) EMIT2(0x1eb4)
		    return OK;

	    case 'B': case 0x181: case 0x243: case 0x1e02:
	    case 0x1e04: case 0x1e06:
		    EMIT2('B')
		    EMIT2(0x181) EMIT2(0x243) EMIT2(0x1e02)
		    EMIT2(0x1e04) EMIT2(0x1e06)
		    return OK;

	    case 'C': case C_cedilla: case 0x106: case 0x108:
	    case 0x10a: case 0x10c: case 0x187: case 0x23b:
	    case 0x1e08: case 0xa792:
		    EMIT2('C') EMIT2(C_cedilla)
		    EMIT2(0x106) EMIT2(0x108) EMIT2(0x10a)
		    EMIT2(0x10c) EMIT2(0x187) EMIT2(0x23b)
		    EMIT2(0x1e08) EMIT2(0xa792)
		    return OK;

	    case 'D': case 0x10e: case 0x110: case 0x18a:
	    case 0x1e0a: case 0x1e0c: case 0x1e0e: case 0x1e10:
	    case 0x1e12:
		    EMIT2('D') EMIT2(0x10e) EMIT2(0x110) EMIT2(0x18a)
		    EMIT2(0x1e0a) EMIT2(0x1e0c) EMIT2(0x1e0e)
		    EMIT2(0x1e10) EMIT2(0x1e12)
		    return OK;

	    case 'E': case E_grave: case E_acute: case E_circumflex:
	    case E_diaeresis: case 0x112: case 0x114: case 0x116:
	    case 0x118: case 0x11a: case 0x204: case 0x206:
	    case 0x228: case 0x246: case 0x1e14: case 0x1e16:
	    case 0x1e18: case 0x1e1a: case 0x1e1c: case 0x1eb8:
	    case 0x1eba: case 0x1ebc: case 0x1ebe: case 0x1ec0:
	    case 0x1ec2: case 0x1ec4: case 0x1ec6:
		    EMIT2('E') EMIT2(E_grave) EMIT2(E_acute)
		    EMIT2(E_circumflex) EMIT2(E_diaeresis)
		    EMIT2(0x112) EMIT2(0x114) EMIT2(0x116)
		    EMIT2(0x118) EMIT2(0x11a) EMIT2(0x204)
		    EMIT2(0x206) EMIT2(0x228) EMIT2(0x246)
		    EMIT2(0x1e14) EMIT2(0x1e16) EMIT2(0x1e18)
		    EMIT2(0x1e1a) EMIT2(0x1e1c) EMIT2(0x1eb8)
		    EMIT2(0x1eba) EMIT2(0x1ebc) EMIT2(0x1ebe)
		    EMIT2(0x1ec0) EMIT2(0x1ec2) EMIT2(0x1ec4)
		    EMIT2(0x1ec6)
		    return OK;

	    case 'F': case 0x191: case 0x1e1e: case 0xa798:
		    EMIT2('F') EMIT2(0x191) EMIT2(0x1e1e) EMIT2(0xa798)
		    return OK;

	    case 'G': case 0x11c: case 0x11e: case 0x120:
	    case 0x122: case 0x193: case 0x1e4: case 0x1e6:
	    case 0x1f4: case 0x1e20: case 0xa7a0:
		    EMIT2('G') EMIT2(0x11c) EMIT2(0x11e) EMIT2(0x120)
		    EMIT2(0x122) EMIT2(0x193) EMIT2(0x1e4)
		    EMIT2(0x1e6) EMIT2(0x1f4) EMIT2(0x1e20)
		    EMIT2(0xa7a0)
		    return OK;

	    case 'H': case 0x124: case 0x126: case 0x21e:
	    case 0x1e22: case 0x1e24: case 0x1e26: case 0x1e28:
	    case 0x1e2a: case 0x2c67:
		    EMIT2('H') EMIT2(0x124) EMIT2(0x126) EMIT2(0x21e)
		    EMIT2(0x1e22) EMIT2(0x1e24) EMIT2(0x1e26)
		    EMIT2(0x1e28) EMIT2(0x1e2a) EMIT2(0x2c67)
		    return OK;

	    case 'I': case I_grave: case I_acute: case I_circumflex:
	    case I_diaeresis: case 0x128: case 0x12a: case 0x12c:
	    case 0x12e: case 0x130: case 0x197: case 0x1cf:
	    case 0x208: case 0x20a: case 0x1e2c: case 0x1e2e:
	    case 0x1ec8: case 0x1eca:
		    EMIT2('I') EMIT2(I_grave) EMIT2(I_acute)
		    EMIT2(I_circumflex) EMIT2(I_diaeresis)
		    EMIT2(0x128) EMIT2(0x12a) EMIT2(0x12c)
		    EMIT2(0x12e) EMIT2(0x130) EMIT2(0x197)
		    EMIT2(0x1cf) EMIT2(0x208) EMIT2(0x20a)
		    EMIT2(0x1e2c) EMIT2(0x1e2e) EMIT2(0x1ec8)
		    EMIT2(0x1eca)
		    return OK;

	    case 'J': case 0x134: case 0x248:
		    EMIT2('J') EMIT2(0x134) EMIT2(0x248)
		    return OK;

	    case 'K': case 0x136: case 0x198: case 0x1e8: case 0x1e30:
	    case 0x1e32: case 0x1e34: case 0x2c69: case 0xa740:
		    EMIT2('K') EMIT2(0x136) EMIT2(0x198) EMIT2(0x1e8)
		    EMIT2(0x1e30) EMIT2(0x1e32) EMIT2(0x1e34)
		    EMIT2(0x2c69) EMIT2(0xa740)
		    return OK;

	    case 'L': case 0x139: case 0x13b: case 0x13d:
	    case 0x13f: case 0x141: case 0x23d: case 0x1e36:
	    case 0x1e38: case 0x1e3a: case 0x1e3c: case 0x2c60:
		    EMIT2('L') EMIT2(0x139) EMIT2(0x13b)
		    EMIT2(0x13d) EMIT2(0x13f) EMIT2(0x141)
		    EMIT2(0x23d) EMIT2(0x1e36) EMIT2(0x1e38)
		    EMIT2(0x1e3a) EMIT2(0x1e3c) EMIT2(0x2c60)
		    return OK;

	    case 'M': case 0x1e3e: case 0x1e40: case 0x1e42:
		    EMIT2('M') EMIT2(0x1e3e) EMIT2(0x1e40)
		    EMIT2(0x1e42)
		    return OK;

	    case 'N': case N_virguilla:
	    case 0x143: case 0x145: case 0x147: case 0x1f8:
	    case 0x1e44: case 0x1e46: case 0x1e48: case 0x1e4a:
	    case 0xa7a4:
		    EMIT2('N') EMIT2(N_virguilla)
		    EMIT2(0x143) EMIT2(0x145) EMIT2(0x147)
		    EMIT2(0x1f8) EMIT2(0x1e44) EMIT2(0x1e46)
		    EMIT2(0x1e48) EMIT2(0x1e4a) EMIT2(0xa7a4)
		    return OK;

	    case 'O': case O_grave: case O_acute: case O_circumflex:
	    case O_virguilla: case O_diaeresis: case O_slash:
	    case 0x14c: case 0x14e: case 0x150: case 0x19f:
	    case 0x1a0: case 0x1d1: case 0x1ea: case 0x1ec:
	    case 0x1fe: case 0x20c: case 0x20e: case 0x22a:
	    case 0x22c: case 0x22e: case 0x230: case 0x1e4c:
	    case 0x1e4e: case 0x1e50: case 0x1e52: case 0x1ecc:
	    case 0x1ece: case 0x1ed0: case 0x1ed2: case 0x1ed4:
	    case 0x1ed6: case 0x1ed8: case 0x1eda: case 0x1edc:
	    case 0x1ede: case 0x1ee0: case 0x1ee2:
		    EMIT2('O') EMIT2(O_grave) EMIT2(O_acute)
		    EMIT2(O_circumflex) EMIT2(O_virguilla)
		    EMIT2(O_diaeresis) EMIT2(O_slash)
		    EMIT2(0x14c) EMIT2(0x14e) EMIT2(0x150)
		    EMIT2(0x19f) EMIT2(0x1a0) EMIT2(0x1d1)
		    EMIT2(0x1ea) EMIT2(0x1ec) EMIT2(0x1fe)
		    EMIT2(0x20c) EMIT2(0x20e) EMIT2(0x22a)
		    EMIT2(0x22c) EMIT2(0x22e) EMIT2(0x230)
		    EMIT2(0x1e4c) EMIT2(0x1e4e) EMIT2(0x1e50)
		    EMIT2(0x1e52) EMIT2(0x1ecc) EMIT2(0x1ece)
		    EMIT2(0x1ed0) EMIT2(0x1ed2) EMIT2(0x1ed4)
		    EMIT2(0x1ed6) EMIT2(0x1ed8) EMIT2(0x1eda)
		    EMIT2(0x1edc) EMIT2(0x1ede) EMIT2(0x1ee0)
		    EMIT2(0x1ee2)
		    return OK;

	    case 'P': case 0x1a4: case 0x1e54: case 0x1e56: case 0x2c63:
		    EMIT2('P') EMIT2(0x1a4) EMIT2(0x1e54) EMIT2(0x1e56)
		    EMIT2(0x2c63)
		    return OK;

	    case 'Q': case 0x24a:
		    EMIT2('Q') EMIT2(0x24a)
		    return OK;

	    case 'R': case 0x154: case 0x156: case 0x158: case 0x210:
	    case 0x212: case 0x24c: case 0x1e58: case 0x1e5a:
	    case 0x1e5c: case 0x1e5e: case 0x2c64: case 0xa7a6:
		    EMIT2('R') EMIT2(0x154) EMIT2(0x156) EMIT2(0x158)
		    EMIT2(0x210) EMIT2(0x212) EMIT2(0x24c) EMIT2(0x1e58)
		    EMIT2(0x1e5a) EMIT2(0x1e5c) EMIT2(0x1e5e) EMIT2(0x2c64)
		    EMIT2(0xa7a6)
		    return OK;

	    case 'S': case 0x15a: case 0x15c: case 0x15e: case 0x160:
	    case 0x218: case 0x1e60: case 0x1e62: case 0x1e64:
	    case 0x1e66: case 0x1e68: case 0x2c7e: case 0xa7a8:
		    EMIT2('S') EMIT2(0x15a) EMIT2(0x15c) EMIT2(0x15e)
		    EMIT2(0x160) EMIT2(0x218) EMIT2(0x1e60) EMIT2(0x1e62)
		    EMIT2(0x1e64) EMIT2(0x1e66) EMIT2(0x1e68) EMIT2(0x2c7e)
		    EMIT2(0xa7a8)
		    return OK;

	    case 'T': case 0x162: case 0x164: case 0x166: case 0x1ac:
	    case 0x1ae: case 0x21a: case 0x23e: case 0x1e6a: case 0x1e6c:
	    case 0x1e6e: case 0x1e70:
		    EMIT2('T') EMIT2(0x162) EMIT2(0x164) EMIT2(0x166)
		    EMIT2(0x1ac) EMIT2(0x1ae) EMIT2(0x23e) EMIT2(0x21a)
		    EMIT2(0x1e6a) EMIT2(0x1e6c) EMIT2(0x1e6e) EMIT2(0x1e70)
		    return OK;

	    case 'U': case U_grave: case U_acute: case U_diaeresis:
	    case U_circumflex: case 0x168: case 0x16a: case 0x16c:
	    case 0x16e: case 0x170: case 0x172: case 0x1af:
	    case 0x1d3: case 0x1d5: case 0x1d7: case 0x1d9:
	    case 0x1db: case 0x214: case 0x216: case 0x244:
	    case 0x1e72: case 0x1e74: case 0x1e76: case 0x1e78:
	    case 0x1e7a: case 0x1ee4: case 0x1ee6: case 0x1ee8:
	    case 0x1eea: case 0x1eec: case 0x1eee: case 0x1ef0:
		    EMIT2('U') EMIT2(U_grave) EMIT2(U_acute)
		    EMIT2(U_diaeresis) EMIT2(U_circumflex)
		    EMIT2(0x168) EMIT2(0x16a)
		    EMIT2(0x16c) EMIT2(0x16e) EMIT2(0x170)
		    EMIT2(0x172) EMIT2(0x1af) EMIT2(0x1d3)
		    EMIT2(0x1d5) EMIT2(0x1d7) EMIT2(0x1d9)
		    EMIT2(0x1db) EMIT2(0x214) EMIT2(0x216)
		    EMIT2(0x244) EMIT2(0x1e72) EMIT2(0x1e74)
		    EMIT2(0x1e76) EMIT2(0x1e78) EMIT2(0x1e7a)
		    EMIT2(0x1ee4) EMIT2(0x1ee6) EMIT2(0x1ee8)
		    EMIT2(0x1eea) EMIT2(0x1eec) EMIT2(0x1eee)
		    EMIT2(0x1ef0)
		    return OK;

	    case 'V': case 0x1b2: case 0x1e7c: case 0x1e7e:
		    EMIT2('V') EMIT2(0x1b2) EMIT2(0x1e7c) EMIT2(0x1e7e)
		    return OK;

	    case 'W': case 0x174: case 0x1e80: case 0x1e82: case 0x1e84:
	    case 0x1e86: case 0x1e88:
		    EMIT2('W') EMIT2(0x174) EMIT2(0x1e80) EMIT2(0x1e82)
		    EMIT2(0x1e84) EMIT2(0x1e86) EMIT2(0x1e88)
		    return OK;

	    case 'X': case 0x1e8a: case 0x1e8c:
		    EMIT2('X') EMIT2(0x1e8a) EMIT2(0x1e8c)
		    return OK;

	    case 'Y': case Y_acute: case 0x176: case 0x178:
	    case 0x1b3: case 0x232: case 0x24e: case 0x1e8e:
	    case 0x1ef2: case 0x1ef4: case 0x1ef6: case 0x1ef8:
		    EMIT2('Y') EMIT2(Y_acute)
		    EMIT2(0x176) EMIT2(0x178) EMIT2(0x1b3)
		    EMIT2(0x232) EMIT2(0x24e) EMIT2(0x1e8e)
		    EMIT2(0x1ef2) EMIT2(0x1ef4) EMIT2(0x1ef6)
		    EMIT2(0x1ef8)
		    return OK;

	    case 'Z': case 0x179: case 0x17b: case 0x17d:
	    case 0x1b5: case 0x1e90: case 0x1e92: case 0x1e94:
	    case 0x2c6b:
		    EMIT2('Z') EMIT2(0x179) EMIT2(0x17b) EMIT2(0x17d)
		    EMIT2(0x1b5) EMIT2(0x1e90) EMIT2(0x1e92)
		    EMIT2(0x1e94) EMIT2(0x2c6b)
		    return OK;

	    case 'a': case a_grave: case a_acute: case a_circumflex:
	    case a_virguilla: case a_diaeresis: case a_ring:
	    case 0x101: case 0x103: case 0x105: case 0x1ce:
	    case 0x1df: case 0x1e1: case 0x1fb: case 0x201:
	    case 0x203: case 0x227: case 0x1d8f: case 0x1e01:
	    case 0x1e9a: case 0x1ea1: case 0x1ea3: case 0x1ea5:
	    case 0x1ea7: case 0x1ea9: case 0x1eab: case 0x1ead:
	    case 0x1eaf: case 0x1eb1: case 0x1eb3: case 0x1eb5:
	    case 0x1eb7: case 0x2c65:
		    EMIT2('a') EMIT2(a_grave) EMIT2(a_acute)
		    EMIT2(a_circumflex) EMIT2(a_virguilla)
		    EMIT2(a_diaeresis) EMIT2(a_ring)
		    EMIT2(0x101) EMIT2(0x103) EMIT2(0x105)
		    EMIT2(0x1ce) EMIT2(0x1df) EMIT2(0x1e1)
		    EMIT2(0x1fb) EMIT2(0x201) EMIT2(0x203)
		    EMIT2(0x227) EMIT2(0x1d8f) EMIT2(0x1e01)
		    EMIT2(0x1e9a) EMIT2(0x1ea1) EMIT2(0x1ea3)
		    EMIT2(0x1ea5) EMIT2(0x1ea7) EMIT2(0x1ea9)
		    EMIT2(0x1eab) EMIT2(0x1ead) EMIT2(0x1eaf)
		    EMIT2(0x1eb1) EMIT2(0x1eb3) EMIT2(0x1eb5)
		    EMIT2(0x1eb7) EMIT2(0x2c65)
		    return OK;

	    case 'b': case 0x180: case 0x253: case 0x1d6c: case 0x1d80:
	    case 0x1e03: case 0x1e05: case 0x1e07:
		    EMIT2('b') EMIT2(0x180) EMIT2(0x253) EMIT2(0x1d6c)
		    EMIT2(0x1d80) EMIT2(0x1e03) EMIT2(0x1e05) EMIT2(0x1e07)
		    return OK;

	    case 'c': case c_cedilla: case 0x107: case 0x109: case 0x10b:
	    case 0x10d: case 0x188: case 0x23c: case 0x1e09: case 0xa793:
	    case 0xa794:
		    EMIT2('c') EMIT2(c_cedilla)
		    EMIT2(0x107) EMIT2(0x109) EMIT2(0x10b)
		    EMIT2(0x10d) EMIT2(0x188) EMIT2(0x23c)
		    EMIT2(0x1e09) EMIT2(0xa793) EMIT2(0xa794)
		    return OK;

	    case 'd': case 0x10f: case 0x111: case 0x257: case 0x1d6d:
	    case 0x1d81: case 0x1d91: case 0x1e0b: case 0x1e0d: case 0x1e0f:
	    case 0x1e11: case 0x1e13:
		    EMIT2('d') EMIT2(0x10f) EMIT2(0x111)
		    EMIT2(0x257) EMIT2(0x1d6d) EMIT2(0x1d81)
		    EMIT2(0x1d91) EMIT2(0x1e0b) EMIT2(0x1e0d)
		    EMIT2(0x1e0f) EMIT2(0x1e11) EMIT2(0x1e13)
		    return OK;

	    case 'e': case e_grave: case e_acute: case e_circumflex:
	    case e_diaeresis: case 0x113: case 0x115: case 0x117:
	    case 0x119: case 0x11b: case 0x205: case 0x207:
	    case 0x229: case 0x247: case 0x1d92: case 0x1e15:
	    case 0x1e17: case 0x1e19: case 0x1e1b: case 0x1e1d:
	    case 0x1eb9: case 0x1ebb: case 0x1ebd: case 0x1ebf:
	    case 0x1ec1: case 0x1ec3: case 0x1ec5: case 0x1ec7:
		    EMIT2('e') EMIT2(e_grave) EMIT2(e_acute)
		    EMIT2(e_circumflex) EMIT2(e_diaeresis)
		    EMIT2(0x113) EMIT2(0x115)
		    EMIT2(0x117) EMIT2(0x119) EMIT2(0x11b)
		    EMIT2(0x205) EMIT2(0x207) EMIT2(0x229)
		    EMIT2(0x247) EMIT2(0x1d92) EMIT2(0x1e15)
		    EMIT2(0x1e17) EMIT2(0x1e19) EMIT2(0x1e1b)
		    EMIT2(0x1e1d) EMIT2(0x1eb9) EMIT2(0x1ebb)
		    EMIT2(0x1ebd) EMIT2(0x1ebf) EMIT2(0x1ec1)
		    EMIT2(0x1ec3) EMIT2(0x1ec5) EMIT2(0x1ec7)
		    return OK;

	    case 'f': case 0x192: case 0x1d6e: case 0x1d82:
	    case 0x1e1f: case 0xa799:
		    EMIT2('f') EMIT2(0x192) EMIT2(0x1d6e) EMIT2(0x1d82)
		    EMIT2(0x1e1f) EMIT2(0xa799)
		    return OK;

	    case 'g': case 0x11d: case 0x11f: case 0x121: case 0x123:
	    case 0x1e5: case 0x1e7: case 0x1f5: case 0x260: case 0x1d83:
	    case 0x1e21: case 0xa7a1:
		    EMIT2('g') EMIT2(0x11d) EMIT2(0x11f) EMIT2(0x121)
		    EMIT2(0x123) EMIT2(0x1e5) EMIT2(0x1e7)
		    EMIT2(0x1f5) EMIT2(0x260) EMIT2(0x1d83)
		    EMIT2(0x1e21) EMIT2(0xa7a1)
		    return OK;

	    case 'h': case 0x125: case 0x127: case 0x21f: case 0x1e23:
	    case 0x1e25: case 0x1e27: case 0x1e29: case 0x1e2b:
	    case 0x1e96: case 0x2c68: case 0xa795:
		    EMIT2('h') EMIT2(0x125) EMIT2(0x127) EMIT2(0x21f)
		    EMIT2(0x1e23) EMIT2(0x1e25) EMIT2(0x1e27)
		    EMIT2(0x1e29) EMIT2(0x1e2b) EMIT2(0x1e96)
		    EMIT2(0x2c68) EMIT2(0xa795)
		    return OK;

	    case 'i': case i_grave: case i_acute: case i_circumflex:
	    case i_diaeresis: case 0x129: case 0x12b: case 0x12d:
	    case 0x12f: case 0x1d0: case 0x209: case 0x20b:
	    case 0x268: case 0x1d96: case 0x1e2d: case 0x1e2f:
	    case 0x1ec9: case 0x1ecb:
		    EMIT2('i') EMIT2(i_grave) EMIT2(i_acute)
		    EMIT2(i_circumflex) EMIT2(i_diaeresis)
		    EMIT2(0x129) EMIT2(0x12b) EMIT2(0x12d)
		    EMIT2(0x12f) EMIT2(0x1d0) EMIT2(0x209)
		    EMIT2(0x20b) EMIT2(0x268) EMIT2(0x1d96)
		    EMIT2(0x1e2d) EMIT2(0x1e2f) EMIT2(0x1ec9)
		    EMIT2(0x1ecb) EMIT2(0x1ecb)
		    return OK;

	    case 'j': case 0x135: case 0x1f0: case 0x249:
		    EMIT2('j') EMIT2(0x135) EMIT2(0x1f0) EMIT2(0x249)
		    return OK;

	    case 'k': case 0x137: case 0x199: case 0x1e9: case 0x1d84:
	    case 0x1e31: case 0x1e33: case 0x1e35: case 0x2c6a: case 0xa741:
		    EMIT2('k') EMIT2(0x137) EMIT2(0x199) EMIT2(0x1e9)
		    EMIT2(0x1d84) EMIT2(0x1e31) EMIT2(0x1e33)
		    EMIT2(0x1e35) EMIT2(0x2c6a) EMIT2(0xa741)
		    return OK;

	    case 'l': case 0x13a: case 0x13c: case 0x13e: case 0x140:
	    case 0x142: case 0x19a: case 0x1e37: case 0x1e39: case 0x1e3b:
	    case 0x1e3d: case 0x2c61:
		    EMIT2('l') EMIT2(0x13a) EMIT2(0x13c)
		    EMIT2(0x13e) EMIT2(0x140) EMIT2(0x142)
		    EMIT2(0x19a) EMIT2(0x1e37) EMIT2(0x1e39)
		    EMIT2(0x1e3b) EMIT2(0x1e3d) EMIT2(0x2c61)
		    return OK;

	    case 'm': case 0x1d6f: case 0x1e3f: case 0x1e41: case 0x1e43:
		    EMIT2('m') EMIT2(0x1d6f) EMIT2(0x1e3f)
		    EMIT2(0x1e41) EMIT2(0x1e43)
		    return OK;

	    case 'n': case n_virguilla: case 0x144: case 0x146: case 0x148:
	    case 0x149: case 0x1f9: case 0x1d70: case 0x1d87: case 0x1e45:
	    case 0x1e47: case 0x1e49: case 0x1e4b: case 0xa7a5:
		    EMIT2('n') EMIT2(n_virguilla)
		    EMIT2(0x144) EMIT2(0x146) EMIT2(0x148)
		    EMIT2(0x149) EMIT2(0x1f9) EMIT2(0x1d70)
		    EMIT2(0x1d87) EMIT2(0x1e45) EMIT2(0x1e47)
		    EMIT2(0x1e49) EMIT2(0x1e4b) EMIT2(0xa7a5)
		    return OK;

	    case 'o': case o_grave: case o_acute: case o_circumflex:
	    case o_virguilla: case o_diaeresis: case o_slash:
	    case 0x14d: case 0x14f: case 0x151: case 0x1a1:
	    case 0x1d2: case 0x1eb: case 0x1ed: case 0x1ff:
	    case 0x20d: case 0x20f: case 0x22b: case 0x22d:
	    case 0x22f: case 0x231: case 0x275: case 0x1e4d:
	    case 0x1e4f: case 0x1e51: case 0x1e53: case 0x1ecd:
	    case 0x1ecf: case 0x1ed1: case 0x1ed3: case 0x1ed5:
	    case 0x1ed7: case 0x1ed9: case 0x1edb: case 0x1edd:
	    case 0x1edf: case 0x1ee1: case 0x1ee3:
		    EMIT2('o') EMIT2(o_grave) EMIT2(o_acute)
		    EMIT2(o_circumflex) EMIT2(o_virguilla)
		    EMIT2(o_diaeresis) EMIT2(o_slash)
		    EMIT2(0x14d) EMIT2(0x14f) EMIT2(0x151)
		    EMIT2(0x1a1) EMIT2(0x1d2) EMIT2(0x1eb)
		    EMIT2(0x1ed) EMIT2(0x1ff) EMIT2(0x20d)
		    EMIT2(0x20f) EMIT2(0x22b) EMIT2(0x22d)
		    EMIT2(0x22f) EMIT2(0x231) EMIT2(0x275)
		    EMIT2(0x1e4d) EMIT2(0x1e4f) EMIT2(0x1e51)
		    EMIT2(0x1e53) EMIT2(0x1ecd) EMIT2(0x1ecf)
		    EMIT2(0x1ed1) EMIT2(0x1ed3) EMIT2(0x1ed5)
		    EMIT2(0x1ed7) EMIT2(0x1ed9) EMIT2(0x1edb)
		    EMIT2(0x1edd) EMIT2(0x1edf) EMIT2(0x1ee1)
		    EMIT2(0x1ee3)
		    return OK;

	    case 'p': case 0x1a5: case 0x1d71: case 0x1d7d: case 0x1d88:
	    case 0x1e55: case 0x1e57:
		    EMIT2('p') EMIT2(0x1a5) EMIT2(0x1d71) EMIT2(0x1d7d)
		    EMIT2(0x1d88) EMIT2(0x1e55) EMIT2(0x1e57)
		    return OK;

	    case 'q': case 0x24b: case 0x2a0:
		    EMIT2('q') EMIT2(0x24b) EMIT2(0x2a0)
		    return OK;

	    case 'r': case 0x155: case 0x157: case 0x159: case 0x211:
	    case 0x213: case 0x24d: case 0x27d: case 0x1d72: case 0x1d73:
	    case 0x1d89: case 0x1e59: case 0x1e5b: case 0x1e5d: case 0x1e5f:
	    case 0xa7a7:
		    EMIT2('r') EMIT2(0x155) EMIT2(0x157) EMIT2(0x159)
		    EMIT2(0x211) EMIT2(0x213) EMIT2(0x24d) EMIT2(0x27d)
		    EMIT2(0x1d72) EMIT2(0x1d73) EMIT2(0x1d89) EMIT2(0x1e59)
		    EMIT2(0x1e5b) EMIT2(0x1e5d) EMIT2(0x1e5f) EMIT2(0xa7a7)
		    return OK;

	    case 's': case 0x15b: case 0x15d: case 0x15f: case 0x161:
	    case 0x219: case 0x23f: case 0x1d74: case 0x1d8a: case 0x1e61:
	    case 0x1e63: case 0x1e65: case 0x1e67: case 0x1e69: case 0xa7a9:
		    EMIT2('s') EMIT2(0x15b) EMIT2(0x15d) EMIT2(0x15f)
		    EMIT2(0x161) EMIT2(0x219) EMIT2(0x23f) EMIT2(0x1d74)
		    EMIT2(0x1d8a) EMIT2(0x1e61) EMIT2(0x1e63) EMIT2(0x1e65)
		    EMIT2(0x1e67) EMIT2(0x1e69) EMIT2(0xa7a9)
		    return OK;

	    case 't': case 0x163: case 0x165: case 0x167: case 0x1ab:
	    case 0x1ad: case 0x21b: case 0x288: case 0x1d75: case 0x1e6b:
	    case 0x1e6d: case 0x1e6f: case 0x1e71: case 0x1e97: case 0x2c66:
		    EMIT2('t') EMIT2(0x163) EMIT2(0x165) EMIT2(0x167)
		    EMIT2(0x1ab) EMIT2(0x1ad) EMIT2(0x21b) EMIT2(0x288)
		    EMIT2(0x1d75) EMIT2(0x1e6b) EMIT2(0x1e6d) EMIT2(0x1e6f)
		    EMIT2(0x1e71) EMIT2(0x1e97) EMIT2(0x2c66)
		    return OK;

	    case 'u': case u_grave: case u_acute: case u_circumflex:
	    case u_diaeresis: case 0x169: case 0x16b: case 0x16d:
	    case 0x16f: case 0x171: case 0x173: case 0x1b0: case 0x1d4:
	    case 0x1d6: case 0x1d8: case 0x1da: case 0x1dc: case 0x215:
	    case 0x217: case 0x289: case 0x1d7e: case 0x1d99: case 0x1e73:
	    case 0x1e75: case 0x1e77: case 0x1e79: case 0x1e7b:
	    case 0x1ee5: case 0x1ee7: case 0x1ee9: case 0x1eeb:
	    case 0x1eed: case 0x1eef: case 0x1ef1:
		    EMIT2('u') EMIT2(u_grave) EMIT2(u_acute)
		    EMIT2(u_circumflex) EMIT2(u_diaeresis)
		    EMIT2(0x169) EMIT2(0x16b)
		    EMIT2(0x16d) EMIT2(0x16f) EMIT2(0x171)
		    EMIT2(0x173) EMIT2(0x1d6) EMIT2(0x1d8)
		    EMIT2(0x215) EMIT2(0x217) EMIT2(0x1b0)
		    EMIT2(0x1d4) EMIT2(0x1da) EMIT2(0x1dc)
		    EMIT2(0x289) EMIT2(0x1e73) EMIT2(0x1d7e)
		    EMIT2(0x1d99) EMIT2(0x1e75) EMIT2(0x1e77)
		    EMIT2(0x1e79) EMIT2(0x1e7b) EMIT2(0x1ee5)
		    EMIT2(0x1ee7) EMIT2(0x1ee9) EMIT2(0x1eeb)
		    EMIT2(0x1eed) EMIT2(0x1eef) EMIT2(0x1ef1)
		    return OK;

	    case 'v': case 0x28b: case 0x1d8c: case 0x1e7d: case 0x1e7f:
		    EMIT2('v') EMIT2(0x28b) EMIT2(0x1d8c) EMIT2(0x1e7d)
		    EMIT2(0x1e7f)
		    return OK;

	    case 'w': case 0x175: case 0x1e81: case 0x1e83: case 0x1e85:
	    case 0x1e87: case 0x1e89: case 0x1e98:
		    EMIT2('w') EMIT2(0x175) EMIT2(0x1e81) EMIT2(0x1e83)
		    EMIT2(0x1e85) EMIT2(0x1e87) EMIT2(0x1e89) EMIT2(0x1e98)
		    return OK;

	    case 'x': case 0x1e8b: case 0x1e8d:
		    EMIT2('x') EMIT2(0x1e8b) EMIT2(0x1e8d)
		    return OK;

	    case 'y': case y_acute: case y_diaeresis: case 0x177:
	    case 0x1b4: case 0x233: case 0x24f: case 0x1e8f:
	    case 0x1e99: case 0x1ef3: case 0x1ef5: case 0x1ef7:
	    case 0x1ef9:
		    EMIT2('y') EMIT2(y_acute) EMIT2(y_diaeresis)
		    EMIT2(0x177) EMIT2(0x1b4) EMIT2(0x233) EMIT2(0x24f)
		    EMIT2(0x1e8f) EMIT2(0x1e99) EMIT2(0x1ef3)
		    EMIT2(0x1ef5) EMIT2(0x1ef7) EMIT2(0x1ef9)
		    return OK;

	    case 'z': case 0x17a: case 0x17c: case 0x17e: case 0x1b6:
	    case 0x1d76: case 0x1d8e: case 0x1e91: case 0x1e93:
	    case 0x1e95: case 0x2c6c:
		    EMIT2('z') EMIT2(0x17a) EMIT2(0x17c) EMIT2(0x17e)
		    EMIT2(0x1b6) EMIT2(0x1d76) EMIT2(0x1d8e) EMIT2(0x1e91)
		    EMIT2(0x1e93) EMIT2(0x1e95) EMIT2(0x2c6c)
		    return OK;

	    // default: character itself
	}
    }

    EMIT2(c);
    return OK;
#undef EMIT2
#undef EMIT2
}


nfa_restore_listids(nfa_regprog_T *prog, int *list)
{
    int		    i;
    nfa_state_T	    *p;

    p = &prog->state[0];
    for (i = prog->nstate; --i >= 0; )
    {
	p->lastlist[1] = list[i];
	++p;
    }
}


match_follows(nfa_state_T *startstate, int depth)
{
    nfa_state_T	    *state = startstate;

    // avoid too much recursion
    if (depth > 10)
	return FALSE;

    while (state != NULL)
    {
	switch (state->c)
	{
	    case NFA_MATCH:
	    case NFA_MCLOSE:
	    case NFA_END_INVISIBLE:
	    case NFA_END_INVISIBLE_NEG:
	    case NFA_END_PATTERN:
		return TRUE;

	    case NFA_SPLIT:
		return match_follows(state->out, depth + 1)
				     || match_follows(state->out1, depth + 1);

	    case NFA_START_INVISIBLE:
	    case NFA_START_INVISIBLE_FIRST:
	    case NFA_START_INVISIBLE_BEFORE:
	    case NFA_START_INVISIBLE_BEFORE_FIRST:
	    case NFA_START_INVISIBLE_NEG:
	    case NFA_START_INVISIBLE_NEG_FIRST:
	    case NFA_START_INVISIBLE_BEFORE_NEG:
	    case NFA_START_INVISIBLE_BEFORE_NEG_FIRST:
	    case NFA_COMPOSING:
		// skip ahead to next state
		state = state->out1->out;
		continue;

	    case NFA_ANY:
	    case NFA_ANY_COMPOSING:
	    case NFA_IDENT:
	    case NFA_SIDENT:
	    case NFA_KWORD:
	    case NFA_SKWORD:
	    case NFA_FNAME:
	    case NFA_SFNAME:
	    case NFA_PRINT:
	    case NFA_SPRINT:
	    case NFA_WHITE:
	    case NFA_NWHITE:
	    case NFA_DIGIT:
	    case NFA_NDIGIT:
	    case NFA_HEX:
	    case NFA_NHEX:
	    case NFA_OCTAL:
	    case NFA_NOCTAL:
	    case NFA_WORD:
	    case NFA_NWORD:
	    case NFA_HEAD:
	    case NFA_NHEAD:
	    case NFA_ALPHA:
	    case NFA_NALPHA:
	    case NFA_LOWER:
	    case NFA_NLOWER:
	    case NFA_UPPER:
	    case NFA_NUPPER:
	    case NFA_LOWER_IC:
	    case NFA_NLOWER_IC:
	    case NFA_UPPER_IC:
	    case NFA_NUPPER_IC:
	    case NFA_START_COLL:
	    case NFA_START_NEG_COLL:
	    case NFA_NEWL:
		// state will advance input
		return FALSE;

	    default:
		if (state->c > 0)
		    // state will advance input
		    return FALSE;

		// Others: zero-width or possibly zero-width, might still find
		// a match at the same position, keep looking.
		break;
	}
	state = state->out;
    }
    return FALSE;
}


nfa_re_num_cmp(long_u val, int op, long_u pos)
{
    if (op == 1) return pos > val;
    if (op == 2) return pos < val;
    return val == pos;
}


nfa_regcomp(char_u *expr, int re_flags)
{
    nfa_regprog_T	*prog = NULL;
    size_t		prog_size;
    int			*postfix;

    if (expr == NULL)
	return NULL;

#ifdef DEBUG
    nfa_regengine.expr = expr;
#endif
    nfa_re_flags = re_flags;

    init_class_tab();

    if (nfa_regcomp_start(expr, re_flags) == FAIL)
	return NULL;

    // Build postfix form of the regexp. Needed to build the NFA
    // (and count its size).
    postfix = re2post();
    if (postfix == NULL)
	goto fail;	    // Cascaded (syntax?) error

    /*
     * In order to build the NFA, we parse the input regexp twice:
     * 1. first pass to count size (so we can allocate space)
     * 2. second to emit code
     */
#ifdef ENABLE_LOG
    {
	FILE *f = fopen(NFA_REGEXP_RUN_LOG, "a");

	if (f != NULL)
	{
	    fprintf(f, "\n*****************************\n\n\n\n\tCompiling regexp \"%s\"... hold on !\n", expr);
	    fclose(f);
	}
    }
#endif

    /*
     * PASS 1
     * Count number of NFA states in "nstate". Do not build the NFA.
     */
    post2nfa(postfix, post_ptr, TRUE);

    // allocate the regprog with space for the compiled regexp
    prog_size = sizeof(nfa_regprog_T) + sizeof(nfa_state_T) * (nstate - 1);
    prog = alloc(prog_size);
    if (prog == NULL)
	goto fail;
    state_ptr = prog->state;
    prog->re_in_use = FALSE;

    /*
     * PASS 2
     * Build the NFA
     */
    prog->start = post2nfa(postfix, post_ptr, FALSE);
    if (prog->start == NULL)
	goto fail;

    prog->regflags = regflags;
    prog->engine = &nfa_regengine;
    prog->nstate = nstate;
    prog->has_zend = rex.nfa_has_zend;
    prog->has_backref = rex.nfa_has_backref;
    prog->nsubexp = regnpar;

    nfa_postprocess(prog);

    prog->reganch = nfa_get_reganch(prog->start, 0);
    prog->regstart = nfa_get_regstart(prog->start, 0);
    prog->match_text = nfa_get_match_text(prog->start);

#ifdef ENABLE_LOG
    nfa_postfix_dump(expr, OK);
    nfa_dump(prog);
#endif
#ifdef FEAT_SYN_HL
    // Remember whether this pattern has any \z specials in it.
    prog->reghasz = re_has_z;
#endif
    prog->pattern = vim_strsave(expr);
#ifdef DEBUG
    nfa_regengine.expr = NULL;
#endif

out:
    VIM_CLEAR(post_start);
    post_ptr = post_end = NULL;
    state_ptr = NULL;
    return (regprog_T *)prog;

fail:
    VIM_CLEAR(prog);
#ifdef ENABLE_LOG
    nfa_postfix_dump(expr, FAIL);
#endif
#ifdef DEBUG
    nfa_regengine.expr = NULL;
#endif
    goto out;
}


nfa_regfree(regprog_T *prog)
{
    if (prog != NULL)
    {
	vim_free(((nfa_regprog_T *)prog)->match_text);
	vim_free(((nfa_regprog_T *)prog)->pattern);
	vim_free(prog);
    }
}


alloc_state(int c, nfa_state_T *out, nfa_state_T *out1)
{
    nfa_state_T *s;

    if (istate >= nstate)
	return NULL;

    s = &state_ptr[istate++];

    s->c    = c;
    s->out  = out;
    s->out1 = out1;
    s->val  = 0;

    s->id   = istate;
    s->lastlist[0] = 0;
    s->lastlist[1] = 0;

    return s;
}


st_push(Frag_T s, Frag_T **p, Frag_T *stack_end)
{
    Frag_T *stackp = *p;

    if (stackp >= stack_end)
	return;
    *stackp = s;
    *p = *p + 1;
}


skip_to_start(int c, colnr_T *colp)
{
    char_u *s;

    // Used often, do some work to avoid call overhead.
    if (!rex.reg_ic && !has_mbyte)
	s = vim_strbyte(rex.line + *colp, c);
    else
	s = cstrchr(rex.line + *colp, c);
    if (s == NULL)
	return FAIL;
    *colp = (int)(s - rex.line);
    return OK;
}


nfa_postfix_dump(char_u *expr, int retval)
{
    int *p;
    FILE *f;

    f = fopen(NFA_REGEXP_DUMP_LOG, "a");
    if (f != NULL)
    {
	fprintf(f, "\n-------------------------\n");
	if (retval == FAIL)
	    fprintf(f, ">>> NFA engine failed... \n");
	else if (retval == OK)
	    fprintf(f, ">>> NFA engine succeeded !\n");
	fprintf(f, "Regexp: \"%s\"\nPostfix notation (char): \"", expr);
	for (p = post_start; *p && p < post_ptr; p++)
	{
	    nfa_set_code(*p);
	    fprintf(f, "%s, ", code);
	}
	fprintf(f, "\"\nPostfix notation (int): ");
	for (p = post_start; *p && p < post_ptr; p++)
		fprintf(f, "%d ", *p);
	fprintf(f, "\n\n");
	fclose(f);
    }
}


nfa_get_regstart(nfa_state_T *start, int depth)
{
    nfa_state_T *p = start;

    if (depth > 4)
	return 0;

    while (p != NULL)
    {
	switch (p->c)
	{
	    // all kinds of zero-width matches
	    case NFA_BOL:
	    case NFA_BOF:
	    case NFA_BOW:
	    case NFA_EOW:
	    case NFA_ZSTART:
	    case NFA_ZEND:
	    case NFA_CURSOR:
	    case NFA_VISUAL:
	    case NFA_LNUM:
	    case NFA_LNUM_GT:
	    case NFA_LNUM_LT:
	    case NFA_COL:
	    case NFA_COL_GT:
	    case NFA_COL_LT:
	    case NFA_VCOL:
	    case NFA_VCOL_GT:
	    case NFA_VCOL_LT:
	    case NFA_MARK:
	    case NFA_MARK_GT:
	    case NFA_MARK_LT:

	    case NFA_MOPEN:
	    case NFA_MOPEN1:
	    case NFA_MOPEN2:
	    case NFA_MOPEN3:
	    case NFA_MOPEN4:
	    case NFA_MOPEN5:
	    case NFA_MOPEN6:
	    case NFA_MOPEN7:
	    case NFA_MOPEN8:
	    case NFA_MOPEN9:
	    case NFA_NOPEN:
#ifdef FEAT_SYN_HL
	    case NFA_ZOPEN:
	    case NFA_ZOPEN1:
	    case NFA_ZOPEN2:
	    case NFA_ZOPEN3:
	    case NFA_ZOPEN4:
	    case NFA_ZOPEN5:
	    case NFA_ZOPEN6:
	    case NFA_ZOPEN7:
	    case NFA_ZOPEN8:
	    case NFA_ZOPEN9:
#endif
		p = p->out;
		break;

	    case NFA_SPLIT:
	    {
		int c1 = nfa_get_regstart(p->out, depth + 1);
		int c2 = nfa_get_regstart(p->out1, depth + 1);

		if (c1 == c2)
		    return c1; // yes!
		return 0;
	    }

	    default:
		if (p->c > 0)
		    return p->c; // yes!
		return 0;
	}
    }
    return 0;
}


nfa_regexec_multi(
    regmmatch_T	*rmp,
    win_T	*win,		// window in which to search or NULL
    buf_T	*buf,		// buffer in which to search
    linenr_T	lnum,		// nr of line to start looking for match
    colnr_T	col,		// column to start looking for match
    proftime_T	*tm,		// timeout limit or NULL
    int		*timed_out)	// flag set on timeout or NULL
{
    init_regexec_multi(rmp, win, buf, lnum);
    return nfa_regexec_both(NULL, col, tm, timed_out);
}


nfa_did_time_out()
{
    if (nfa_time_limit != NULL && profile_passed_limit(nfa_time_limit))
    {
	if (nfa_timed_out != NULL)
	    *nfa_timed_out = TRUE;
	return TRUE;
    }
    return FALSE;
}


nfa_regcomp_start(
    char_u	*expr,
    int		re_flags)	    // see vim_regcomp()
{
    size_t	postfix_size;
    int		nstate_max;

    nstate = 0;
    istate = 0;
    // A reasonable estimation for maximum size
    nstate_max = (int)(STRLEN(expr) + 1) * 25;

    // Some items blow up in size, such as [A-z].  Add more space for that.
    // When it is still not enough realloc_post_list() will be used.
    nstate_max += 1000;

    // Size for postfix representation of expr.
    postfix_size = sizeof(int) * nstate_max;

    post_start = alloc(postfix_size);
    if (post_start == NULL)
	return FAIL;
    post_ptr = post_start;
    post_end = post_start + nstate_max;
    wants_nfa = FALSE;
    rex.nfa_has_zend = FALSE;
    rex.nfa_has_backref = FALSE;

    // shared with BT engine
    regcomp_start(expr, re_flags);

    return OK;
}


nfa_regtry(
    nfa_regprog_T   *prog,
    colnr_T	    col,
    proftime_T	    *tm UNUSED,	// timeout limit or NULL
    int		    *timed_out UNUSED)	// flag set on timeout or NULL
{
    int		i;
    regsubs_T	subs, m;
    nfa_state_T	*start = prog->start;
    int		result;
#ifdef ENABLE_LOG
    FILE	*f;
#endif

    rex.input = rex.line + col;
#ifdef FEAT_RELTIME
    nfa_time_limit = tm;
    nfa_timed_out = timed_out;
    nfa_time_count = 0;
#endif

#ifdef ENABLE_LOG
    f = fopen(NFA_REGEXP_RUN_LOG, "a");
    if (f != NULL)
    {
	fprintf(f, "\n\n\t=======================================================\n");
#ifdef DEBUG
	fprintf(f, "\tRegexp is \"%s\"\n", nfa_regengine.expr);
#endif
	fprintf(f, "\tInput text is \"%s\" \n", rex.input);
	fprintf(f, "\t=======================================================\n\n");
	nfa_print_state(f, start);
	fprintf(f, "\n\n");
	fclose(f);
    }
    else
	emsg("Could not open temporary log file for writing");
#endif

    clear_sub(&subs.norm);
    clear_sub(&m.norm);
#ifdef FEAT_SYN_HL
    clear_sub(&subs.synt);
    clear_sub(&m.synt);
#endif

    result = nfa_regmatch(prog, start, &subs, &m);
    if (result == FALSE)
	return 0;
    else if (result == NFA_TOO_EXPENSIVE)
	return result;

    cleanup_subexpr();
    if (REG_MULTI)
    {
	for (i = 0; i < subs.norm.in_use; i++)
	{
	    rex.reg_startpos[i].lnum = subs.norm.list.multi[i].start_lnum;
	    rex.reg_startpos[i].col = subs.norm.list.multi[i].start_col;

	    rex.reg_endpos[i].lnum = subs.norm.list.multi[i].end_lnum;
	    rex.reg_endpos[i].col = subs.norm.list.multi[i].end_col;
	}

	if (rex.reg_startpos[0].lnum < 0)
	{
	    rex.reg_startpos[0].lnum = 0;
	    rex.reg_startpos[0].col = col;
	}
	if (rex.reg_endpos[0].lnum < 0)
	{
	    // pattern has a \ze but it didn't match, use current end
	    rex.reg_endpos[0].lnum = rex.lnum;
	    rex.reg_endpos[0].col = (int)(rex.input - rex.line);
	}
	else
	    // Use line number of "\ze".
	    rex.lnum = rex.reg_endpos[0].lnum;
    }
    else
    {
	for (i = 0; i < subs.norm.in_use; i++)
	{
	    rex.reg_startp[i] = subs.norm.list.line[i].start;
	    rex.reg_endp[i] = subs.norm.list.line[i].end;
	}

	if (rex.reg_startp[0] == NULL)
	    rex.reg_startp[0] = rex.line + col;
	if (rex.reg_endp[0] == NULL)
	    rex.reg_endp[0] = rex.input;
    }

#ifdef FEAT_SYN_HL
    // Package any found \z(...\) matches for export. Default is none.
    unref_extmatch(re_extmatch_out);
    re_extmatch_out = NULL;

    if (prog->reghasz == REX_SET)
    {
	cleanup_zsubexpr();
	re_extmatch_out = make_extmatch();
	if (re_extmatch_out == NULL)
	    return 0;
	// Loop over \z1, \z2, etc.  There is no \z0.
	for (i = 1; i < subs.synt.in_use; i++)
	{
	    if (REG_MULTI)
	    {
		struct multipos *mpos = &subs.synt.list.multi[i];

		// Only accept single line matches that are valid.
		if (mpos->start_lnum >= 0
			&& mpos->start_lnum == mpos->end_lnum
			&& mpos->end_col >= mpos->start_col)
		    re_extmatch_out->matches[i] =
			vim_strnsave(reg_getline(mpos->start_lnum)
							    + mpos->start_col,
					     mpos->end_col - mpos->start_col);
	    }
	    else
	    {
		struct linepos *lpos = &subs.synt.list.line[i];

		if (lpos->start != NULL && lpos->end != NULL)
		    re_extmatch_out->matches[i] =
			    vim_strnsave(lpos->start, lpos->end - lpos->start);
	    }
	}
    }
#endif

    return 1 + rex.lnum;
}


has_state_with_pos(
    nfa_list_T		*l,	// runtime state list
    nfa_state_T		*state,	// state to update
    regsubs_T		*subs,	// pointers to subexpressions
    nfa_pim_T		*pim)	// postponed match or NULL
{
    nfa_thread_T	*thread;
    int			i;

    for (i = 0; i < l->n; ++i)
    {
	thread = &l->t[i];
	if (thread->state->id == state->id
		&& sub_equal(&thread->subs.norm, &subs->norm)
#ifdef FEAT_SYN_HL
		&& (!rex.nfa_has_zsubexpr
				|| sub_equal(&thread->subs.synt, &subs->synt))
#endif
		&& pim_equal(&thread->pim, pim))
	    return TRUE;
    }
    return FALSE;
}


match_backref(
    regsub_T	*sub,	    // pointers to subexpressions
    int		subidx,
    int		*bytelen)   // out: length of match in bytes
{
    int		len;

    if (sub->in_use <= subidx)
    {
retempty:
	// backref was not set, match an empty string
	*bytelen = 0;
	return TRUE;
    }

    if (REG_MULTI)
    {
	if (sub->list.multi[subidx].start_lnum < 0
				       || sub->list.multi[subidx].end_lnum < 0)
	    goto retempty;
	if (sub->list.multi[subidx].start_lnum == rex.lnum
			       && sub->list.multi[subidx].end_lnum == rex.lnum)
	{
	    len = sub->list.multi[subidx].end_col
					  - sub->list.multi[subidx].start_col;
	    if (cstrncmp(rex.line + sub->list.multi[subidx].start_col,
							 rex.input, &len) == 0)
	    {
		*bytelen = len;
		return TRUE;
	    }
	}
	else
	{
	    if (match_with_backref(
			sub->list.multi[subidx].start_lnum,
			sub->list.multi[subidx].start_col,
			sub->list.multi[subidx].end_lnum,
			sub->list.multi[subidx].end_col,
			bytelen) == RA_MATCH)
		return TRUE;
	}
    }
    else
    {
	if (sub->list.line[subidx].start == NULL
					|| sub->list.line[subidx].end == NULL)
	    goto retempty;
	len = (int)(sub->list.line[subidx].end - sub->list.line[subidx].start);
	if (cstrncmp(sub->list.line[subidx].start, rex.input, &len) == 0)
	{
	    *bytelen = len;
	    return TRUE;
	}
    }
    return FALSE;
}


st_error(int *postfix UNUSED, int *end UNUSED, int *p UNUSED)
{
#ifdef NFA_REGEXP_ERROR_LOG
    FILE *df;
    int *p2;

    df = fopen(NFA_REGEXP_ERROR_LOG, "a");
    if (df)
    {
	fprintf(df, "Error popping the stack!\n");
# ifdef DEBUG
	fprintf(df, "Current regexp is \"%s\"\n", nfa_regengine.expr);
# endif
	fprintf(df, "Postfix form is: ");
# ifdef DEBUG
	for (p2 = postfix; p2 < end; p2++)
	{
	    nfa_set_code(*p2);
	    fprintf(df, "%s, ", code);
	}
	nfa_set_code(*p);
	fprintf(df, "\nCurrent position is: ");
	for (p2 = postfix; p2 <= p; p2 ++)
	{
	    nfa_set_code(*p2);
	    fprintf(df, "%s, ", code);
	}
# else
	for (p2 = postfix; p2 < end; p2++)
	    fprintf(df, "%d, ", *p2);
	fprintf(df, "\nCurrent position is: ");
	for (p2 = postfix; p2 <= p; p2 ++)
	    fprintf(df, "%d, ", *p2);
# endif
	fprintf(df, "\n--------------------------\n");
	fclose(df);
    }
#endif
    emsg(_("E874: (NFA) Could not pop the stack!"));
}


addstate(
    nfa_list_T		*l,	    // runtime state list
    nfa_state_T		*state,	    // state to update
    regsubs_T		*subs_arg,  // pointers to subexpressions
    nfa_pim_T		*pim,	    // postponed look-behind match
    int			off_arg)    // byte offset, when -1 go to next line
{
    int			subidx;
    int			off = off_arg;
    int			add_here = FALSE;
    int			listindex = 0;
    int			k;
    int			found = FALSE;
    nfa_thread_T	*thread;
    struct multipos	save_multipos;
    int			save_in_use;
    char_u		*save_ptr;
    int			i;
    regsub_T		*sub;
    regsubs_T		*subs = subs_arg;
    static regsubs_T	temp_subs;
#ifdef ENABLE_LOG
    int			did_print = FALSE;
#endif
    static int		depth = 0;

    // This function is called recursively.  When the depth is too much we run
    // out of stack and crash, limit recursiveness here.
    if (++depth >= 5000 || subs == NULL)
    {
	--depth;
	return NULL;
    }

    if (off_arg <= -ADDSTATE_HERE_OFFSET)
    {
	add_here = TRUE;
	off = 0;
	listindex = -(off_arg + ADDSTATE_HERE_OFFSET);
    }

    switch (state->c)
    {
	case NFA_NCLOSE:
	case NFA_MCLOSE:
	case NFA_MCLOSE1:
	case NFA_MCLOSE2:
	case NFA_MCLOSE3:
	case NFA_MCLOSE4:
	case NFA_MCLOSE5:
	case NFA_MCLOSE6:
	case NFA_MCLOSE7:
	case NFA_MCLOSE8:
	case NFA_MCLOSE9:
#ifdef FEAT_SYN_HL
	case NFA_ZCLOSE:
	case NFA_ZCLOSE1:
	case NFA_ZCLOSE2:
	case NFA_ZCLOSE3:
	case NFA_ZCLOSE4:
	case NFA_ZCLOSE5:
	case NFA_ZCLOSE6:
	case NFA_ZCLOSE7:
	case NFA_ZCLOSE8:
	case NFA_ZCLOSE9:
#endif
	case NFA_MOPEN:
	case NFA_ZEND:
	case NFA_SPLIT:
	case NFA_EMPTY:
	    // These nodes are not added themselves but their "out" and/or
	    // "out1" may be added below.
	    break;

	case NFA_BOL:
	case NFA_BOF:
	    // "^" won't match past end-of-line, don't bother trying.
	    // Except when at the end of the line, or when we are going to the
	    // next line for a look-behind match.
	    if (rex.input > rex.line
		    && *rex.input != NUL
		    && (nfa_endp == NULL
			|| !REG_MULTI
			|| rex.lnum == nfa_endp->se_u.pos.lnum))
		goto skip_add;
	    // FALLTHROUGH

	case NFA_MOPEN1:
	case NFA_MOPEN2:
	case NFA_MOPEN3:
	case NFA_MOPEN4:
	case NFA_MOPEN5:
	case NFA_MOPEN6:
	case NFA_MOPEN7:
	case NFA_MOPEN8:
	case NFA_MOPEN9:
#ifdef FEAT_SYN_HL
	case NFA_ZOPEN:
	case NFA_ZOPEN1:
	case NFA_ZOPEN2:
	case NFA_ZOPEN3:
	case NFA_ZOPEN4:
	case NFA_ZOPEN5:
	case NFA_ZOPEN6:
	case NFA_ZOPEN7:
	case NFA_ZOPEN8:
	case NFA_ZOPEN9:
#endif
	case NFA_NOPEN:
	case NFA_ZSTART:
	    // These nodes need to be added so that we can bail out when it
	    // was added to this list before at the same position to avoid an
	    // endless loop for "\(\)*"

	default:
	    if (state->lastlist[nfa_ll_index] == l->id && state->c != NFA_SKIP)
	    {
		// This state is already in the list, don't add it again,
		// unless it is an MOPEN that is used for a backreference or
		// when there is a PIM. For NFA_MATCH check the position,
		// lower position is preferred.
		if (!rex.nfa_has_backref && pim == NULL && !l->has_pim
						     && state->c != NFA_MATCH)
		{
		    // When called from addstate_here() do insert before
		    // existing states.
		    if (add_here)
		    {
			for (k = 0; k < l->n && k < listindex; ++k)
			    if (l->t[k].state->id == state->id)
			    {
				found = TRUE;
				break;
			    }
		    }
		    if (!add_here || found)
		    {
skip_add:
#ifdef ENABLE_LOG
			nfa_set_code(state->c);
			fprintf(log_fd, "> Not adding state %d to list %d. char %d: %s pim: %s has_pim: %d found: %d\n",
			    abs(state->id), l->id, state->c, code,
			    pim == NULL ? "NULL" : "yes", l->has_pim, found);
#endif
			--depth;
			return subs;
		    }
		}

		// Do not add the state again when it exists with the same
		// positions.
		if (has_state_with_pos(l, state, subs, pim))
		    goto skip_add;
	    }

	    // When there are backreferences or PIMs the number of states may
	    // be (a lot) bigger than anticipated.
	    if (l->n == l->len)
	    {
		int		newlen = l->len * 3 / 2 + 50;
		size_t		newsize = newlen * sizeof(nfa_thread_T);
		nfa_thread_T	*newt;

		if ((long)(newsize >> 10) >= p_mmp)
		{
		    emsg(_(e_maxmempat));
		    --depth;
		    return NULL;
		}
		if (subs != &temp_subs)
		{
		    // "subs" may point into the current array, need to make a
		    // copy before it becomes invalid.
		    copy_sub(&temp_subs.norm, &subs->norm);
#ifdef FEAT_SYN_HL
		    if (rex.nfa_has_zsubexpr)
			copy_sub(&temp_subs.synt, &subs->synt);
#endif
		    subs = &temp_subs;
		}

		newt = vim_realloc(l->t, newsize);
		if (newt == NULL)
		{
		    // out of memory
		    --depth;
		    return NULL;
		}
		l->t = newt;
		l->len = newlen;
	    }

	    // add the state to the list
	    state->lastlist[nfa_ll_index] = l->id;
	    thread = &l->t[l->n++];
	    thread->state = state;
	    if (pim == NULL)
		thread->pim.result = NFA_PIM_UNUSED;
	    else
	    {
		copy_pim(&thread->pim, pim);
		l->has_pim = TRUE;
	    }
	    copy_sub(&thread->subs.norm, &subs->norm);
#ifdef FEAT_SYN_HL
	    if (rex.nfa_has_zsubexpr)
		copy_sub(&thread->subs.synt, &subs->synt);
#endif
#ifdef ENABLE_LOG
	    report_state("Adding", &thread->subs.norm, state, l->id, pim);
	    did_print = TRUE;
#endif
    }

#ifdef ENABLE_LOG
    if (!did_print)
	report_state("Processing", &subs->norm, state, l->id, pim);
#endif
    switch (state->c)
    {
	case NFA_MATCH:
	    break;

	case NFA_SPLIT:
	    // order matters here
	    subs = addstate(l, state->out, subs, pim, off_arg);
	    subs = addstate(l, state->out1, subs, pim, off_arg);
	    break;

	case NFA_EMPTY:
	case NFA_NOPEN:
	case NFA_NCLOSE:
	    subs = addstate(l, state->out, subs, pim, off_arg);
	    break;

	case NFA_MOPEN:
	case NFA_MOPEN1:
	case NFA_MOPEN2:
	case NFA_MOPEN3:
	case NFA_MOPEN4:
	case NFA_MOPEN5:
	case NFA_MOPEN6:
	case NFA_MOPEN7:
	case NFA_MOPEN8:
	case NFA_MOPEN9:
#ifdef FEAT_SYN_HL
	case NFA_ZOPEN:
	case NFA_ZOPEN1:
	case NFA_ZOPEN2:
	case NFA_ZOPEN3:
	case NFA_ZOPEN4:
	case NFA_ZOPEN5:
	case NFA_ZOPEN6:
	case NFA_ZOPEN7:
	case NFA_ZOPEN8:
	case NFA_ZOPEN9:
#endif
	case NFA_ZSTART:
	    if (state->c == NFA_ZSTART)
	    {
		subidx = 0;
		sub = &subs->norm;
	    }
#ifdef FEAT_SYN_HL
	    else if (state->c >= NFA_ZOPEN && state->c <= NFA_ZOPEN9)
	    {
		subidx = state->c - NFA_ZOPEN;
		sub = &subs->synt;
	    }
#endif
	    else
	    {
		subidx = state->c - NFA_MOPEN;
		sub = &subs->norm;
	    }

	    // avoid compiler warnings
	    save_ptr = NULL;
	    CLEAR_FIELD(save_multipos);

	    // Set the position (with "off" added) in the subexpression.  Save
	    // and restore it when it was in use.  Otherwise fill any gap.
	    if (REG_MULTI)
	    {
		if (subidx < sub->in_use)
		{
		    save_multipos = sub->list.multi[subidx];
		    save_in_use = -1;
		}
		else
		{
		    save_in_use = sub->in_use;
		    for (i = sub->in_use; i < subidx; ++i)
		    {
			sub->list.multi[i].start_lnum = -1;
			sub->list.multi[i].end_lnum = -1;
		    }
		    sub->in_use = subidx + 1;
		}
		if (off == -1)
		{
		    sub->list.multi[subidx].start_lnum = rex.lnum + 1;
		    sub->list.multi[subidx].start_col = 0;
		}
		else
		{
		    sub->list.multi[subidx].start_lnum = rex.lnum;
		    sub->list.multi[subidx].start_col =
					  (colnr_T)(rex.input - rex.line + off);
		}
		sub->list.multi[subidx].end_lnum = -1;
	    }
	    else
	    {
		if (subidx < sub->in_use)
		{
		    save_ptr = sub->list.line[subidx].start;
		    save_in_use = -1;
		}
		else
		{
		    save_in_use = sub->in_use;
		    for (i = sub->in_use; i < subidx; ++i)
		    {
			sub->list.line[i].start = NULL;
			sub->list.line[i].end = NULL;
		    }
		    sub->in_use = subidx + 1;
		}
		sub->list.line[subidx].start = rex.input + off;
	    }

	    subs = addstate(l, state->out, subs, pim, off_arg);
	    if (subs == NULL)
		break;
	    // "subs" may have changed, need to set "sub" again
#ifdef FEAT_SYN_HL
	    if (state->c >= NFA_ZOPEN && state->c <= NFA_ZOPEN9)
		sub = &subs->synt;
	    else
#endif
		sub = &subs->norm;

	    if (save_in_use == -1)
	    {
		if (REG_MULTI)
		    sub->list.multi[subidx] = save_multipos;
		else
		    sub->list.line[subidx].start = save_ptr;
	    }
	    else
		sub->in_use = save_in_use;
	    break;

	case NFA_MCLOSE:
	    if (rex.nfa_has_zend && (REG_MULTI
			? subs->norm.list.multi[0].end_lnum >= 0
			: subs->norm.list.line[0].end != NULL))
	    {
		// Do not overwrite the position set by \ze.
		subs = addstate(l, state->out, subs, pim, off_arg);
		break;
	    }
	    // FALLTHROUGH
	case NFA_MCLOSE1:
	case NFA_MCLOSE2:
	case NFA_MCLOSE3:
	case NFA_MCLOSE4:
	case NFA_MCLOSE5:
	case NFA_MCLOSE6:
	case NFA_MCLOSE7:
	case NFA_MCLOSE8:
	case NFA_MCLOSE9:
#ifdef FEAT_SYN_HL
	case NFA_ZCLOSE:
	case NFA_ZCLOSE1:
	case NFA_ZCLOSE2:
	case NFA_ZCLOSE3:
	case NFA_ZCLOSE4:
	case NFA_ZCLOSE5:
	case NFA_ZCLOSE6:
	case NFA_ZCLOSE7:
	case NFA_ZCLOSE8:
	case NFA_ZCLOSE9:
#endif
	case NFA_ZEND:
	    if (state->c == NFA_ZEND)
	    {
		subidx = 0;
		sub = &subs->norm;
	    }
#ifdef FEAT_SYN_HL
	    else if (state->c >= NFA_ZCLOSE && state->c <= NFA_ZCLOSE9)
	    {
		subidx = state->c - NFA_ZCLOSE;
		sub = &subs->synt;
	    }
#endif
	    else
	    {
		subidx = state->c - NFA_MCLOSE;
		sub = &subs->norm;
	    }

	    // We don't fill in gaps here, there must have been an MOPEN that
	    // has done that.
	    save_in_use = sub->in_use;
	    if (sub->in_use <= subidx)
		sub->in_use = subidx + 1;
	    if (REG_MULTI)
	    {
		save_multipos = sub->list.multi[subidx];
		if (off == -1)
		{
		    sub->list.multi[subidx].end_lnum = rex.lnum + 1;
		    sub->list.multi[subidx].end_col = 0;
		}
		else
		{
		    sub->list.multi[subidx].end_lnum = rex.lnum;
		    sub->list.multi[subidx].end_col =
					  (colnr_T)(rex.input - rex.line + off);
		}
		// avoid compiler warnings
		save_ptr = NULL;
	    }
	    else
	    {
		save_ptr = sub->list.line[subidx].end;
		sub->list.line[subidx].end = rex.input + off;
		// avoid compiler warnings
		CLEAR_FIELD(save_multipos);
	    }

	    subs = addstate(l, state->out, subs, pim, off_arg);
	    if (subs == NULL)
		break;
	    // "subs" may have changed, need to set "sub" again
#ifdef FEAT_SYN_HL
	    if (state->c >= NFA_ZCLOSE && state->c <= NFA_ZCLOSE9)
		sub = &subs->synt;
	    else
#endif
		sub = &subs->norm;

	    if (REG_MULTI)
		sub->list.multi[subidx] = save_multipos;
	    else
		sub->list.line[subidx].end = save_ptr;
	    sub->in_use = save_in_use;
	    break;
    }
    --depth;
    return subs;
}


copy_sub(regsub_T *to, regsub_T *from)
{
    to->in_use = from->in_use;
    if (from->in_use > 0)
    {
	// Copy the match start and end positions.
	if (REG_MULTI)
	    mch_memmove(&to->list.multi[0],
			&from->list.multi[0],
			sizeof(struct multipos) * from->in_use);
	else
	    mch_memmove(&to->list.line[0],
			&from->list.line[0],
			sizeof(struct linepos) * from->in_use);
    }
}


match_zref(
    int		subidx,
    int		*bytelen)   // out: length of match in bytes
{
    int		len;

    cleanup_zsubexpr();
    if (re_extmatch_in == NULL || re_extmatch_in->matches[subidx] == NULL)
    {
	// backref was not set, match an empty string
	*bytelen = 0;
	return TRUE;
    }

    len = (int)STRLEN(re_extmatch_in->matches[subidx]);
    if (cstrncmp(re_extmatch_in->matches[subidx], rex.input, &len) == 0)
    {
	*bytelen = len;
	return TRUE;
    }
    return FALSE;
}