From df1e965e12cdd48c11057ee6e15346ee2b8b02f5 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 14 Feb 2008 17:33:37 +0000
Subject: [PATCH] Sync our regex code with upstream changes since last time we
 did this, which was Tcl 8.4.8.  The main changes are to remove the
 never-fully-implemented code for multi-character collating elements, and to
 const-ify some stuff a bit more fully.  In combination with the recent
 security patch, this commit brings us into line with Tcl 8.5.0.

Note that I didn't make any effort to duplicate a lot of cosmetic changes
that they made to bring their copy into line with their own style
guidelines, such as adding braces around single-line IF bodies.  Most of
those we either had done already (such as ANSI-fication of function headers)
or there is no point because pgindent would undo the change anyway.
---
 src/backend/regex/regc_color.c  |  35 +---
 src/backend/regex/regc_cvec.c   |  93 ++-------
 src/backend/regex/regc_lex.c    |  32 +--
 src/backend/regex/regc_locale.c |  90 +++-----
 src/backend/regex/regc_nfa.c    |  69 +++---
 src/backend/regex/regcomp.c     | 360 +++++---------------------------
 src/backend/regex/regerror.c    |   8 +-
 src/include/regex/regcustom.h   |   6 +-
 src/include/regex/regguts.h     |  18 +-
 9 files changed, 165 insertions(+), 546 deletions(-)

diff --git a/src/backend/regex/regc_color.c b/src/backend/regex/regc_color.c
index 87eb1e4958..e15fd4b788 100644
--- a/src/backend/regex/regc_color.c
+++ b/src/backend/regex/regc_color.c
@@ -28,7 +28,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regc_color.c,v 1.8 2008/01/03 20:47:55 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regc_color.c,v 1.9 2008/02/14 17:33:37 tgl Exp $
  *
  *
  * Note that there are some incestuous relationships between this code and
@@ -222,7 +222,6 @@ static color					/* COLORLESS for error */
 newcolor(struct colormap * cm)
 {
 	struct colordesc *cd;
-	struct colordesc *new;
 	size_t		n;
 
 	if (CISERR())
@@ -245,24 +244,25 @@ newcolor(struct colormap * cm)
 	else
 	{
 		/* oops, must allocate more */
+		struct colordesc *newCd;
+
 		n = cm->ncds * 2;
 		if (cm->cd == cm->cdspace)
 		{
-			new = (struct colordesc *) MALLOC(n *
-											  sizeof(struct colordesc));
-			if (new != NULL)
-				memcpy(VS(new), VS(cm->cdspace), cm->ncds *
+			newCd = (struct colordesc *) MALLOC(n * sizeof(struct colordesc));
+			if (newCd != NULL)
+				memcpy(VS(newCd), VS(cm->cdspace), cm->ncds *
 					   sizeof(struct colordesc));
 		}
 		else
-			new = (struct colordesc *) REALLOC(cm->cd,
-											   n * sizeof(struct colordesc));
-		if (new == NULL)
+			newCd = (struct colordesc *)
+				REALLOC(cm->cd, n * sizeof(struct colordesc));
+		if (newCd == NULL)
 		{
 			CERR(REG_ESPACE);
 			return COLORLESS;
 		}
-		cm->cd = new;
+		cm->cd = newCd;
 		cm->ncds = n;
 		assert(cm->max < cm->ncds - 1);
 		cm->max++;
@@ -634,21 +634,6 @@ uncolorchain(struct colormap * cm,
 	a->colorchainRev = NULL;
 }
 
-/*
- * singleton - is this character in its own color?
- */
-static int						/* predicate */
-singleton(struct colormap * cm,
-		  chr c)
-{
-	color		co;				/* color of c */
-
-	co = GETCOLOR(cm, c);
-	if (cm->cd[co].nchrs == 1 && cm->cd[co].sub == NOSUB)
-		return 1;
-	return 0;
-}
-
 /*
  * rainbow - add arcs of all full colors (but one) between specified states
  */
diff --git a/src/backend/regex/regc_cvec.c b/src/backend/regex/regc_cvec.c
index 719c4c5ef3..25bfae3e32 100644
--- a/src/backend/regex/regc_cvec.c
+++ b/src/backend/regex/regc_cvec.c
@@ -28,33 +28,31 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regc_cvec.c,v 1.5 2005/10/15 02:49:24 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regc_cvec.c,v 1.6 2008/02/14 17:33:37 tgl Exp $
  *
  */
 
+/*
+ * Notes:
+ * Only (selected) functions in _this_ file should treat chr* as non-constant.
+ */
+
 /*
  * newcvec - allocate a new cvec
  */
 static struct cvec *
 newcvec(int nchrs,				/* to hold this many chrs... */
-		int nranges,			/* ... and this many ranges... */
-		int nmcces)				/* ... and this many MCCEs */
+		int nranges)			/* ... and this many ranges */
 {
-	size_t		n;
-	size_t		nc;
-	struct cvec *cv;
+	size_t		nc = (size_t) nchrs + (size_t) nranges * 2;
+	size_t		n = sizeof(struct cvec) + nc * sizeof(chr);
+	struct cvec *cv = (struct cvec *) MALLOC(n);
 
-	nc = (size_t) nchrs + (size_t) nmcces *(MAXMCCE + 1) + (size_t) nranges *2;
-
-	n = sizeof(struct cvec) + (size_t) (nmcces - 1) * sizeof(chr *)
-		+ nc * sizeof(chr);
-	cv = (struct cvec *) MALLOC(n);
 	if (cv == NULL)
 		return NULL;
 	cv->chrspace = nchrs;
-	cv->chrs = (chr *) &cv->mcces[nmcces];		/* chrs just after MCCE ptrs */
-	cv->mccespace = nmcces;
-	cv->ranges = cv->chrs + nchrs + nmcces * (MAXMCCE + 1);
+	cv->chrs = (chr *) (((char *) cv) + sizeof(struct cvec));
+	cv->ranges = cv->chrs + nchrs;
 	cv->rangespace = nranges;
 	return clearcvec(cv);
 }
@@ -66,17 +64,9 @@ newcvec(int nchrs,				/* to hold this many chrs... */
 static struct cvec *
 clearcvec(struct cvec * cv)
 {
-	int			i;
-
 	assert(cv != NULL);
 	cv->nchrs = 0;
-	assert(cv->chrs == (chr *) &cv->mcces[cv->mccespace]);
-	cv->nmcces = 0;
-	cv->nmccechrs = 0;
 	cv->nranges = 0;
-	for (i = 0; i < cv->mccespace; i++)
-		cv->mcces[i] = NULL;
-
 	return cv;
 }
 
@@ -87,7 +77,6 @@ static void
 addchr(struct cvec * cv,		/* character vector */
 	   chr c)					/* character to add */
 {
-	assert(cv->nchrs < cv->chrspace - cv->nmccechrs);
 	cv->chrs[cv->nchrs++] = (chr) c;
 }
 
@@ -105,73 +94,21 @@ addrange(struct cvec * cv,		/* character vector */
 	cv->nranges++;
 }
 
-/*
- * addmcce - add an MCCE to a cvec
- */
-static void
-addmcce(struct cvec * cv,		/* character vector */
-		chr *startp,			/* beginning of text */
-		chr *endp)				/* just past end of text */
-{
-	int			len;
-	int			i;
-	chr		   *s;
-	chr		   *d;
-
-	if (startp == NULL && endp == NULL)
-		return;
-	len = endp - startp;
-	assert(len > 0);
-	assert(cv->nchrs + len < cv->chrspace - cv->nmccechrs);
-	assert(cv->nmcces < cv->mccespace);
-	d = &cv->chrs[cv->chrspace - cv->nmccechrs - len - 1];
-	cv->mcces[cv->nmcces++] = d;
-	for (s = startp, i = len; i > 0; s++, i--)
-		*d++ = *s;
-	*d++ = 0;					/* endmarker */
-	assert(d == &cv->chrs[cv->chrspace - cv->nmccechrs]);
-	cv->nmccechrs += len + 1;
-}
-
-/*
- * haschr - does a cvec contain this chr?
- */
-static int						/* predicate */
-haschr(struct cvec * cv,		/* character vector */
-	   chr c)					/* character to test for */
-{
-	int			i;
-	chr		   *p;
-
-	for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--)
-	{
-		if (*p == c)
-			return 1;
-	}
-	for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--)
-	{
-		if ((*p <= c) && (c <= *(p + 1)))
-			return 1;
-	}
-	return 0;
-}
-
 /*
  * getcvec - get a cvec, remembering it as v->cv
  */
 static struct cvec *
 getcvec(struct vars * v,		/* context */
 		int nchrs,				/* to hold this many chrs... */
-		int nranges,			/* ... and this many ranges... */
-		int nmcces)				/* ... and this many MCCEs */
+		int nranges)			/* ... and this many ranges */
 {
 	if (v->cv != NULL && nchrs <= v->cv->chrspace &&
-		nranges <= v->cv->rangespace && nmcces <= v->cv->mccespace)
+		nranges <= v->cv->rangespace)
 		return clearcvec(v->cv);
 
 	if (v->cv != NULL)
 		freecvec(v->cv);
-	v->cv = newcvec(nchrs, nranges, nmcces);
+	v->cv = newcvec(nchrs, nranges);
 	if (v->cv == NULL)
 		ERR(REG_ESPACE);
 
diff --git a/src/backend/regex/regc_lex.c b/src/backend/regex/regc_lex.c
index fc86ca322a..d2fc591ed8 100644
--- a/src/backend/regex/regc_lex.c
+++ b/src/backend/regex/regc_lex.c
@@ -28,7 +28,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regc_lex.c,v 1.7 2008/01/03 20:47:55 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regc_lex.c,v 1.8 2008/02/14 17:33:37 tgl Exp $
  *
  */
 
@@ -201,8 +201,8 @@ prefixes(struct vars * v)
  */
 static void
 lexnest(struct vars * v,
-		chr *beginp,			/* start of interpolation */
-		chr *endp)				/* one past end of interpolation */
+		const chr *beginp,		/* start of interpolation */
+		const chr *endp)		/* one past end of interpolation */
 {
 	assert(v->savenow == NULL); /* only one level of nesting */
 	v->savenow = v->now;
@@ -214,47 +214,47 @@ lexnest(struct vars * v,
 /*
  * string constants to interpolate as expansions of things like \d
  */
-static chr	backd[] = {			/* \d */
+static const chr backd[] = {			/* \d */
 	CHR('['), CHR('['), CHR(':'),
 	CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'),
 	CHR(':'), CHR(']'), CHR(']')
 };
-static chr	backD[] = {			/* \D */
+static const chr backD[] = {			/* \D */
 	CHR('['), CHR('^'), CHR('['), CHR(':'),
 	CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'),
 	CHR(':'), CHR(']'), CHR(']')
 };
-static chr	brbackd[] = {		/* \d within brackets */
+static const chr brbackd[] = {			/* \d within brackets */
 	CHR('['), CHR(':'),
 	CHR('d'), CHR('i'), CHR('g'), CHR('i'), CHR('t'),
 	CHR(':'), CHR(']')
 };
-static chr	backs[] = {			/* \s */
+static const chr backs[] = {			/* \s */
 	CHR('['), CHR('['), CHR(':'),
 	CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'),
 	CHR(':'), CHR(']'), CHR(']')
 };
-static chr	backS[] = {			/* \S */
+static const chr backS[] = {			/* \S */
 	CHR('['), CHR('^'), CHR('['), CHR(':'),
 	CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'),
 	CHR(':'), CHR(']'), CHR(']')
 };
-static chr	brbacks[] = {		/* \s within brackets */
+static const chr brbacks[] = {			/* \s within brackets */
 	CHR('['), CHR(':'),
 	CHR('s'), CHR('p'), CHR('a'), CHR('c'), CHR('e'),
 	CHR(':'), CHR(']')
 };
-static chr	backw[] = {			/* \w */
+static const chr backw[] = {			/* \w */
 	CHR('['), CHR('['), CHR(':'),
 	CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'),
 	CHR(':'), CHR(']'), CHR('_'), CHR(']')
 };
-static chr	backW[] = {			/* \W */
+static const chr backW[] = {			/* \W */
 	CHR('['), CHR('^'), CHR('['), CHR(':'),
 	CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'),
 	CHR(':'), CHR(']'), CHR('_'), CHR(']')
 };
-static chr	brbackw[] = {		/* \w within brackets */
+static const chr brbackw[] = {			/* \w within brackets */
 	CHR('['), CHR(':'),
 	CHR('a'), CHR('l'), CHR('n'), CHR('u'), CHR('m'),
 	CHR(':'), CHR(']'), CHR('_')
@@ -722,7 +722,7 @@ lexescape(struct vars * v)
 	static chr	esc[] = {
 		CHR('E'), CHR('S'), CHR('C')
 	};
-	chr		   *save;
+	const chr  *save;
 
 	assert(v->cflags & REG_ADVF);
 
@@ -1080,7 +1080,7 @@ brenext(struct vars * v,
 static void
 skip(struct vars * v)
 {
-	chr		   *start = v->now;
+	const chr  *start = v->now;
 
 	assert(v->cflags & REG_EXPANDED);
 
@@ -1119,8 +1119,8 @@ newline(void)
  */
 static chr
 chrnamed(struct vars * v,
-		 chr *startp,			/* start of name */
-		 chr *endp,				/* just past end of name */
+		 const chr *startp,		/* start of name */
+		 const chr *endp,		/* just past end of name */
 		 chr lastresort)		/* what to return if name lookup fails */
 {
 	celt		c;
diff --git a/src/backend/regex/regc_locale.c b/src/backend/regex/regc_locale.c
index 09c1bd127d..28f5e7ca12 100644
--- a/src/backend/regex/regc_locale.c
+++ b/src/backend/regex/regc_locale.c
@@ -47,15 +47,15 @@
  * permission to use and distribute the software in accordance with the
  * terms specified in this license.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regc_locale.c,v 1.8 2005/11/22 18:17:19 momjian Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regc_locale.c,v 1.9 2008/02/14 17:33:37 tgl Exp $
  */
 
 /* ASCII character-name table */
 
-static struct cname
+static const struct cname
 {
-	char	   *name;
-	char		code;
+	const char *name;
+	const char	code;
 }	cnames[] =
 
 {
@@ -423,46 +423,15 @@ pg_wc_tolower(pg_wchar c)
 }
 
 
-/*
- * nmcces - how many distinct MCCEs are there?
- */
-static int
-nmcces(struct vars * v)
-{
-	/*
-	 * No multi-character collating elements defined at the moment.
-	 */
-	return 0;
-}
-
-/*
- * nleaders - how many chrs can be first chrs of MCCEs?
- */
-static int
-nleaders(struct vars * v)
-{
-	return 0;
-}
-
-/*
- * allmcces - return a cvec with all the MCCEs of the locale
- */
-static struct cvec *
-allmcces(struct vars * v,		/* context */
-		 struct cvec * cv)		/* this is supposed to have enough room */
-{
-	return clearcvec(cv);
-}
-
 /*
  * element - map collating-element name to celt
  */
 static celt
 element(struct vars * v,		/* context */
-		chr *startp,			/* points to start of name */
-		chr *endp)				/* points just past end of name */
+		const chr *startp,		/* points to start of name */
+		const chr *endp)		/* points just past end of name */
 {
-	struct cname *cn;
+	const struct cname *cn;
 	size_t		len;
 
 	/* generic:  one-chr names stand for themselves */
@@ -513,7 +482,7 @@ range(struct vars * v,			/* context */
 
 	if (!cases)
 	{							/* easy version */
-		cv = getcvec(v, 0, 1, 0);
+		cv = getcvec(v, 0, 1);
 		NOERRN();
 		addrange(cv, a, b);
 		return cv;
@@ -527,7 +496,7 @@ range(struct vars * v,			/* context */
 
 	nchrs = (b - a + 1) * 2 + 4;
 
-	cv = getcvec(v, nchrs, 0, 0);
+	cv = getcvec(v, nchrs, 0);
 	NOERRN();
 
 	for (c = a; c <= b; c++)
@@ -550,7 +519,6 @@ range(struct vars * v,			/* context */
 static int						/* predicate */
 before(celt x, celt y)
 {
-	/* trivial because no MCCEs */
 	if (x < y)
 		return 1;
 	return 0;
@@ -571,7 +539,7 @@ eclass(struct vars * v,			/* context */
 	/* crude fake equivalence class for testing */
 	if ((v->cflags & REG_FAKE) && c == 'x')
 	{
-		cv = getcvec(v, 4, 0, 0);
+		cv = getcvec(v, 4, 0);
 		addchr(cv, (chr) 'x');
 		addchr(cv, (chr) 'y');
 		if (cases)
@@ -585,7 +553,7 @@ eclass(struct vars * v,			/* context */
 	/* otherwise, none */
 	if (cases)
 		return allcases(v, c);
-	cv = getcvec(v, 1, 0, 0);
+	cv = getcvec(v, 1, 0);
 	assert(cv != NULL);
 	addchr(cv, (chr) c);
 	return cv;
@@ -598,13 +566,13 @@ eclass(struct vars * v,			/* context */
  */
 static struct cvec *
 cclass(struct vars * v,			/* context */
-	   chr *startp,				/* where the name starts */
-	   chr *endp,				/* just past the end of the name */
+	   const chr *startp,		/* where the name starts */
+	   const chr *endp,			/* just past the end of the name */
 	   int cases)				/* case-independent? */
 {
 	size_t		len;
 	struct cvec *cv = NULL;
-	char	  **namePtr;
+	const char **namePtr;
 	int			i,
 				index;
 
@@ -612,7 +580,7 @@ cclass(struct vars * v,			/* context */
 	 * The following arrays define the valid character class names.
 	 */
 
-	static char *classNames[] = {
+	static const char *classNames[] = {
 		"alnum", "alpha", "ascii", "blank", "cntrl", "digit", "graph",
 		"lower", "print", "punct", "space", "upper", "xdigit", NULL
 	};
@@ -662,7 +630,7 @@ cclass(struct vars * v,			/* context */
 	switch ((enum classes) index)
 	{
 		case CC_PRINT:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -673,7 +641,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_ALNUM:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -684,7 +652,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_ALPHA:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -695,27 +663,27 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_ASCII:
-			cv = getcvec(v, 0, 1, 0);
+			cv = getcvec(v, 0, 1);
 			if (cv)
 				addrange(cv, 0, 0x7f);
 			break;
 		case CC_BLANK:
-			cv = getcvec(v, 2, 0, 0);
+			cv = getcvec(v, 2, 0);
 			addchr(cv, '\t');
 			addchr(cv, ' ');
 			break;
 		case CC_CNTRL:
-			cv = getcvec(v, 0, 2, 0);
+			cv = getcvec(v, 0, 2);
 			addrange(cv, 0x0, 0x1f);
 			addrange(cv, 0x7f, 0x9f);
 			break;
 		case CC_DIGIT:
-			cv = getcvec(v, 0, 1, 0);
+			cv = getcvec(v, 0, 1);
 			if (cv)
 				addrange(cv, (chr) '0', (chr) '9');
 			break;
 		case CC_PUNCT:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -726,7 +694,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_XDIGIT:
-			cv = getcvec(v, 0, 3, 0);
+			cv = getcvec(v, 0, 3);
 			if (cv)
 			{
 				addrange(cv, '0', '9');
@@ -735,7 +703,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_SPACE:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -746,7 +714,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_LOWER:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -757,7 +725,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_UPPER:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -768,7 +736,7 @@ cclass(struct vars * v,			/* context */
 			}
 			break;
 		case CC_GRAPH:
-			cv = getcvec(v, UCHAR_MAX, 0, 0);
+			cv = getcvec(v, UCHAR_MAX, 0);
 			if (cv)
 			{
 				for (i = 0; i <= UCHAR_MAX; i++)
@@ -802,7 +770,7 @@ allcases(struct vars * v,		/* context */
 	lc = pg_wc_tolower((chr) c);
 	uc = pg_wc_toupper((chr) c);
 
-	cv = getcvec(v, 2, 0, 0);
+	cv = getcvec(v, 2, 0);
 	addchr(cv, lc);
 	if (lc != uc)
 		addchr(cv, uc);
diff --git a/src/backend/regex/regc_nfa.c b/src/backend/regex/regc_nfa.c
index ea382df7f9..4e307f5c15 100644
--- a/src/backend/regex/regc_nfa.c
+++ b/src/backend/regex/regc_nfa.c
@@ -28,7 +28,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regc_nfa.c,v 1.5 2008/01/03 20:47:55 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regc_nfa.c,v 1.6 2008/02/14 17:33:37 tgl Exp $
  *
  *
  * One or two things that technically ought to be in here
@@ -349,8 +349,6 @@ newarc(struct nfa * nfa,
 
 	if (COLORED(a) && nfa->parent == NULL)
 		colorchain(nfa->cm, a);
-
-	return;
 }
 
 /*
@@ -361,8 +359,6 @@ allocarc(struct nfa * nfa,
 		 struct state * s)
 {
 	struct arc *a;
-	struct arcbatch *new;
-	int			i;
 
 	/* shortcut */
 	if (s->free == NULL && s->noas < ABSIZE)
@@ -375,22 +371,25 @@ allocarc(struct nfa * nfa,
 	/* if none at hand, get more */
 	if (s->free == NULL)
 	{
-		new = (struct arcbatch *) MALLOC(sizeof(struct arcbatch));
-		if (new == NULL)
+		struct arcbatch *newAb;
+		int			i;
+
+		newAb = (struct arcbatch *) MALLOC(sizeof(struct arcbatch));
+		if (newAb == NULL)
 		{
 			NERR(REG_ESPACE);
 			return NULL;
 		}
-		new->next = s->oas.next;
-		s->oas.next = new;
+		newAb->next = s->oas.next;
+		s->oas.next = newAb;
 
 		for (i = 0; i < ABSIZE; i++)
 		{
-			new->a[i].type = 0;
-			new->a[i].freechain = &new->a[i + 1];
+			newAb->a[i].type = 0;
+			newAb->a[i].freechain = &newAb->a[i + 1];
 		}
-		new->a[ABSIZE - 1].freechain = NULL;
-		s->free = &new->a[0];
+		newAb->a[ABSIZE - 1].freechain = NULL;
+		s->free = &newAb->a[0];
 	}
 	assert(s->free != NULL);
 
@@ -495,20 +494,20 @@ cparc(struct nfa * nfa,
  */
 static void
 moveins(struct nfa * nfa,
-		struct state * old,
-		struct state * new)
+		struct state * oldState,
+		struct state * newState)
 {
 	struct arc *a;
 
-	assert(old != new);
+	assert(oldState != newState);
 
-	while ((a = old->ins) != NULL)
+	while ((a = oldState->ins) != NULL)
 	{
-		cparc(nfa, a, a->from, new);
+		cparc(nfa, a, a->from, newState);
 		freearc(nfa, a);
 	}
-	assert(old->nins == 0);
-	assert(old->ins == NULL);
+	assert(oldState->nins == 0);
+	assert(oldState->ins == NULL);
 }
 
 /*
@@ -516,15 +515,15 @@ moveins(struct nfa * nfa,
  */
 static void
 copyins(struct nfa * nfa,
-		struct state * old,
-		struct state * new)
+		struct state * oldState,
+		struct state * newState)
 {
 	struct arc *a;
 
-	assert(old != new);
+	assert(oldState != newState);
 
-	for (a = old->ins; a != NULL; a = a->inchain)
-		cparc(nfa, a, a->from, new);
+	for (a = oldState->ins; a != NULL; a = a->inchain)
+		cparc(nfa, a, a->from, newState);
 }
 
 /*
@@ -532,16 +531,16 @@ copyins(struct nfa * nfa,
  */
 static void
 moveouts(struct nfa * nfa,
-		 struct state * old,
-		 struct state * new)
+		 struct state * oldState,
+		 struct state * newState)
 {
 	struct arc *a;
 
-	assert(old != new);
+	assert(oldState != newState);
 
-	while ((a = old->outs) != NULL)
+	while ((a = oldState->outs) != NULL)
 	{
-		cparc(nfa, a, new, a->to);
+		cparc(nfa, a, newState, a->to);
 		freearc(nfa, a);
 	}
 }
@@ -551,15 +550,15 @@ moveouts(struct nfa * nfa,
  */
 static void
 copyouts(struct nfa * nfa,
-		 struct state * old,
-		 struct state * new)
+		 struct state * oldState,
+		 struct state * newState)
 {
 	struct arc *a;
 
-	assert(old != new);
+	assert(oldState != newState);
 
-	for (a = old->outs; a != NULL; a = a->outchain)
-		cparc(nfa, a, new, a->to);
+	for (a = oldState->outs; a != NULL; a = a->outchain)
+		cparc(nfa, a, newState, a->to);
 }
 
 /*
diff --git a/src/backend/regex/regcomp.c b/src/backend/regex/regcomp.c
index 1eaca67b9a..89f4f6f737 100644
--- a/src/backend/regex/regcomp.c
+++ b/src/backend/regex/regcomp.c
@@ -28,7 +28,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regcomp.c,v 1.45 2007/10/06 16:05:54 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regcomp.c,v 1.46 2008/02/14 17:33:37 tgl Exp $
  *
  */
 
@@ -51,11 +51,9 @@ static void repeat(struct vars *, struct state *, struct state *, int, int);
 static void bracket(struct vars *, struct state *, struct state *);
 static void cbracket(struct vars *, struct state *, struct state *);
 static void brackpart(struct vars *, struct state *, struct state *);
-static chr *scanplain(struct vars *);
-static void leaders(struct vars *, struct cvec *);
+static const chr *scanplain(struct vars *);
 static void onechr(struct vars *, chr, struct state *, struct state *);
 static void dovec(struct vars *, struct cvec *, struct state *, struct state *);
-static celt nextleader(struct vars *, chr, chr);
 static void wordchrs(struct vars *);
 static struct subre *subre(struct vars *, int, int, struct state *, struct state *);
 static void freesubre(struct vars *, struct subre *);
@@ -74,12 +72,12 @@ static void rfree(regex_t *);
 static void dump(regex_t *, FILE *);
 static void dumpst(struct subre *, FILE *, int);
 static void stdump(struct subre *, FILE *, int);
-static char *stid(struct subre *, char *, size_t);
+static const char *stid(struct subre *, char *, size_t);
 #endif
 /* === regc_lex.c === */
 static void lexstart(struct vars *);
 static void prefixes(struct vars *);
-static void lexnest(struct vars *, chr *, chr *);
+static void lexnest(struct vars *, const chr *, const chr *);
 static void lexword(struct vars *);
 static int	next(struct vars *);
 static int	lexescape(struct vars *);
@@ -87,7 +85,7 @@ static chr	lexdigits(struct vars *, int, int, int);
 static int	brenext(struct vars *, chr);
 static void skip(struct vars *);
 static chr	newline(void);
-static chr	chrnamed(struct vars *, chr *, chr *, chr);
+static chr	chrnamed(struct vars *, const chr *, const chr *, chr);
 
 /* === regc_color.c === */
 static void initcm(struct vars *, struct colormap *);
@@ -105,7 +103,6 @@ static void subblock(struct vars *, chr, struct state *, struct state *);
 static void okcolors(struct nfa *, struct colormap *);
 static void colorchain(struct colormap *, struct arc *);
 static void uncolorchain(struct colormap *, struct arc *);
-static int	singleton(struct colormap *, chr c);
 static void rainbow(struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *);
 static void colorcomplement(struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *);
 
@@ -168,13 +165,11 @@ static void dumpcnfa(struct cnfa *, FILE *);
 static void dumpcstate(int, struct carc *, struct cnfa *, FILE *);
 #endif
 /* === regc_cvec.c === */
-static struct cvec *newcvec(int, int, int);
+static struct cvec *newcvec(int, int);
 static struct cvec *clearcvec(struct cvec *);
 static void addchr(struct cvec *, chr);
 static void addrange(struct cvec *, chr, chr);
-static void addmcce(struct cvec *, chr *, chr *);
-static int	haschr(struct cvec *, chr);
-static struct cvec *getcvec(struct vars *, int, int, int);
+static struct cvec *getcvec(struct vars *, int, int);
 static void freecvec(struct cvec *);
 
 /* === regc_locale.c === */
@@ -189,14 +184,11 @@ static int	pg_wc_ispunct(pg_wchar c);
 static int	pg_wc_isspace(pg_wchar c);
 static pg_wchar pg_wc_toupper(pg_wchar c);
 static pg_wchar pg_wc_tolower(pg_wchar c);
-static int	nmcces(struct vars *);
-static int	nleaders(struct vars *);
-static struct cvec *allmcces(struct vars *, struct cvec *);
-static celt element(struct vars *, chr *, chr *);
+static celt element(struct vars *, const chr *, const chr *);
 static struct cvec *range(struct vars *, celt, celt, int);
 static int	before(celt, celt);
 static struct cvec *eclass(struct vars *, celt, int);
-static struct cvec *cclass(struct vars *, chr *, chr *, int);
+static struct cvec *cclass(struct vars *, const chr *, const chr *, int);
 static struct cvec *allcases(struct vars *, chr);
 static int	cmp(const chr *, const chr *, size_t);
 static int	casecmp(const chr *, const chr *, size_t);
@@ -206,10 +198,10 @@ static int	casecmp(const chr *, const chr *, size_t);
 struct vars
 {
 	regex_t    *re;
-	chr		   *now;			/* scan pointer into string */
-	chr		   *stop;			/* end of string */
-	chr		   *savenow;		/* saved now and stop for "subroutine call" */
-	chr		   *savestop;
+	const chr  *now;			/* scan pointer into string */
+	const chr  *stop;			/* end of string */
+	const chr  *savenow;		/* saved now and stop for "subroutine call" */
+	const chr  *savestop;
 	int			err;			/* error code (0 if none) */
 	int			cflags;			/* copy of compile flags */
 	int			lasttype;		/* type of previous token */
@@ -230,10 +222,6 @@ struct vars
 	int			ntree;			/* number of tree nodes */
 	struct cvec *cv;			/* interface cvec */
 	struct cvec *cv2;			/* utility cvec */
-	struct cvec *mcces;			/* collating-element information */
-#define  ISCELEADER(v,c) ((v)->mcces != NULL && haschr((v)->mcces, (c)))
-	struct state *mccepbegin;	/* in nfa, start of MCCE prototypes */
-	struct state *mccepend;		/* in nfa, end of MCCE prototypes */
 	struct subre *lacons;		/* lookahead-constraint vector */
 	int			nlacons;		/* size of lacons */
 };
@@ -275,9 +263,8 @@ struct vars
 #define PREFER	'P'				/* length preference */
 
 /* is an arc colored, and hence on a color chain? */
-#define COLORED(a)	((a)->type == PLAIN || (a)->type == AHEAD || \
-							(a)->type == BEHIND)
-
+#define COLORED(a) \
+	((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND)
 
 
 /* static function list */
@@ -322,7 +309,7 @@ pg_regcomp(regex_t *re,
 
 	/* initial setup (after which freev() is callable) */
 	v->re = re;
-	v->now = (chr *) string;
+	v->now = string;
 	v->stop = v->now + len;
 	v->savenow = v->savestop = NULL;
 	v->err = 0;
@@ -341,7 +328,6 @@ pg_regcomp(regex_t *re,
 	v->treefree = NULL;
 	v->cv = NULL;
 	v->cv2 = NULL;
-	v->mcces = NULL;
 	v->lacons = NULL;
 	v->nlacons = 0;
 	re->re_magic = REMAGIC;
@@ -363,19 +349,9 @@ pg_regcomp(regex_t *re,
 	ZAPCNFA(g->search);
 	v->nfa = newnfa(v, v->cm, (struct nfa *) NULL);
 	CNOERR();
-	v->cv = newcvec(100, 20, 10);
+	v->cv = newcvec(100, 20);
 	if (v->cv == NULL)
 		return freev(v, REG_ESPACE);
-	i = nmcces(v);
-	if (i > 0)
-	{
-		v->mcces = newcvec(nleaders(v), 0, i);
-		CNOERR();
-		v->mcces = allmcces(v, v->mcces);
-		leaders(v, v->mcces);
-		addmcce(v->mcces, (chr *) NULL, (chr *) NULL);	/* dummy */
-	}
-	CNOERR();
 
 	/* parsing */
 	lexstart(v);				/* also handles prefixes */
@@ -525,8 +501,6 @@ freev(struct vars * v,
 		freecvec(v->cv);
 	if (v->cv2 != NULL)
 		freecvec(v->cv2);
-	if (v->mcces != NULL)
-		freecvec(v->mcces);
 	if (v->lacons != NULL)
 		freelacons(v->lacons, v->nlacons);
 	ERR(err);					/* nop if err==0 */
@@ -583,15 +557,14 @@ makesearch(struct vars * v,
 		for (b = s->ins; b != NULL; b = b->inchain)
 			if (b->from != pre)
 				break;
-		if (b != NULL)
-		{						/* must be split */
-			if (s->tmp == NULL)
-			{					/* if not already in the list */
-				/* (fixes bugs 505048, 230589, */
-				/* 840258, 504785) */
-				s->tmp = slist;
-				slist = s;
-			}
+		if (b != NULL && s->tmp == NULL)
+		{
+			/*
+			 * Must be split if not already in the list (fixes bugs 505048,
+			 * 230589, 840258, 504785).
+			 */
+			s->tmp = slist;
+			slist = s;
 		}
 	}
 
@@ -1338,13 +1311,6 @@ cbracket(struct vars * v,
 {
 	struct state *left = newstate(v->nfa);
 	struct state *right = newstate(v->nfa);
-	struct state *s;
-	struct arc *a;				/* arc from lp */
-	struct arc *ba;				/* arc from left, from bracket() */
-	struct arc *pa;				/* MCCE-prototype arc */
-	color		co;
-	chr		   *p;
-	int			i;
 
 	NOERR();
 	bracket(v, left, right);
@@ -1354,65 +1320,13 @@ cbracket(struct vars * v,
 
 	assert(lp->nouts == 0);		/* all outarcs will be ours */
 
-	/* easy part of complementing */
+	/*
+	 * Easy part of complementing, and all there is to do since the MCCE code
+	 * was removed.
+	 */
 	colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
 	NOERR();
-	if (v->mcces == NULL)
-	{							/* no MCCEs -- we're done */
-		dropstate(v->nfa, left);
-		assert(right->nins == 0);
-		freestate(v->nfa, right);
-		return;
-	}
-
-	/* but complementing gets messy in the presence of MCCEs... */
-	NOTE(REG_ULOCALE);
-	for (p = v->mcces->chrs, i = v->mcces->nchrs; i > 0; p++, i--)
-	{
-		co = GETCOLOR(v->cm, *p);
-		a = findarc(lp, PLAIN, co);
-		ba = findarc(left, PLAIN, co);
-		if (ba == NULL)
-		{
-			assert(a != NULL);
-			freearc(v->nfa, a);
-		}
-		else
-			assert(a == NULL);
-		s = newstate(v->nfa);
-		NOERR();
-		newarc(v->nfa, PLAIN, co, lp, s);
-		NOERR();
-		pa = findarc(v->mccepbegin, PLAIN, co);
-		assert(pa != NULL);
-		if (ba == NULL)
-		{						/* easy case, need all of them */
-			cloneouts(v->nfa, pa->to, s, rp, PLAIN);
-			newarc(v->nfa, '$', 1, s, rp);
-			newarc(v->nfa, '$', 0, s, rp);
-			colorcomplement(v->nfa, v->cm, AHEAD, pa->to, s, rp);
-		}
-		else
-		{						/* must be selective */
-			if (findarc(ba->to, '$', 1) == NULL)
-			{
-				newarc(v->nfa, '$', 1, s, rp);
-				newarc(v->nfa, '$', 0, s, rp);
-				colorcomplement(v->nfa, v->cm, AHEAD, pa->to,
-								s, rp);
-			}
-			for (pa = pa->to->outs; pa != NULL; pa = pa->outchain)
-				if (findarc(ba->to, PLAIN, pa->co) == NULL)
-					newarc(v->nfa, PLAIN, pa->co, s, rp);
-			if (s->nouts == 0)	/* limit of selectivity: none */
-				dropstate(v->nfa, s);	/* frees arc too */
-		}
-		NOERR();
-	}
-
-	delsub(v->nfa, left, right);
-	assert(left->nouts == 0);
-	freestate(v->nfa, left);
+	dropstate(v->nfa, left);
 	assert(right->nins == 0);
 	freestate(v->nfa, right);
 }
@@ -1428,8 +1342,8 @@ brackpart(struct vars * v,
 	celt		startc;
 	celt		endc;
 	struct cvec *cv;
-	chr		   *startp;
-	chr		   *endp;
+	const chr  *startp;
+	const chr  *endp;
 	chr			c[1];
 
 	/* parse something, get rid of special cases, take shortcuts */
@@ -1442,8 +1356,8 @@ brackpart(struct vars * v,
 		case PLAIN:
 			c[0] = v->nextvalue;
 			NEXT();
-			/* shortcut for ordinary chr (not range, not MCCE leader) */
-			if (!SEE(RANGE) && !ISCELEADER(v, c[0]))
+			/* shortcut for ordinary chr (not range) */
+			if (!SEE(RANGE))
 			{
 				onechr(v, c[0], lp, rp);
 				return;
@@ -1533,10 +1447,10 @@ brackpart(struct vars * v,
  * Certain bits of trickery in lex.c know that this code does not try
  * to look past the final bracket of the [. etc.
  */
-static chr *					/* just after end of sequence */
+static const chr *				/* just after end of sequence */
 scanplain(struct vars * v)
 {
-	chr		   *endp;
+	const chr  *endp;
 
 	assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
 	NEXT();
@@ -1554,52 +1468,6 @@ scanplain(struct vars * v)
 	return endp;
 }
 
-/*
- * leaders - process a cvec of collating elements to also include leaders
- * Also gives all characters involved their own colors, which is almost
- * certainly necessary, and sets up little disconnected subNFA.
- */
-static void
-leaders(struct vars * v,
-		struct cvec * cv)
-{
-	int			mcce;
-	chr		   *p;
-	chr			leader;
-	struct state *s;
-	struct arc *a;
-
-	v->mccepbegin = newstate(v->nfa);
-	v->mccepend = newstate(v->nfa);
-	NOERR();
-
-	for (mcce = 0; mcce < cv->nmcces; mcce++)
-	{
-		p = cv->mcces[mcce];
-		leader = *p;
-		if (!haschr(cv, leader))
-		{
-			addchr(cv, leader);
-			s = newstate(v->nfa);
-			newarc(v->nfa, PLAIN, subcolor(v->cm, leader),
-				   v->mccepbegin, s);
-			okcolors(v->nfa, v->cm);
-		}
-		else
-		{
-			a = findarc(v->mccepbegin, PLAIN,
-						GETCOLOR(v->cm, leader));
-			assert(a != NULL);
-			s = a->to;
-			assert(s != v->mccepend);
-		}
-		p++;
-		assert(*p != 0 && *(p + 1) == 0);		/* only 2-char MCCEs for now */
-		newarc(v->nfa, PLAIN, subcolor(v->cm, *p), s, v->mccepend);
-		okcolors(v->nfa, v->cm);
-	}
-}
-
 /*
  * onechr - fill in arcs for a plain character, and possible case complements
  * This is mostly a shortcut for efficient handling of the common case.
@@ -1622,7 +1490,6 @@ onechr(struct vars * v,
 
 /*
  * dovec - fill in arcs for each element of a cvec
- * This one has to handle the messy cases, like MCCEs and MCCE leaders.
  */
 static void
 dovec(struct vars * v,
@@ -1633,47 +1500,14 @@ dovec(struct vars * v,
 	chr			ch,
 				from,
 				to;
-	celt		ce;
-	chr		   *p;
+	const chr  *p;
 	int			i;
-	color		co;
-	struct cvec *leads;
-	struct arc *a;
-	struct arc *pa;				/* arc in prototype */
-	struct state *s;
-	struct state *ps;			/* state in prototype */
-
-	/* need a place to store leaders, if any */
-	if (nmcces(v) > 0)
-	{
-		assert(v->mcces != NULL);
-		if (v->cv2 == NULL || v->cv2->nchrs < v->mcces->nchrs)
-		{
-			if (v->cv2 != NULL)
-				free(v->cv2);
-			v->cv2 = newcvec(v->mcces->nchrs, 0, v->mcces->nmcces);
-			NOERR();
-			leads = v->cv2;
-		}
-		else
-			leads = clearcvec(v->cv2);
-	}
-	else
-		leads = NULL;
 
-	/* first, get the ordinary characters out of the way */
+	/* ordinary characters */
 	for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--)
 	{
 		ch = *p;
-		if (!ISCELEADER(v, ch))
-			newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp);
-		else
-		{
-			assert(singleton(v->cm, ch));
-			assert(leads != NULL);
-			if (!haschr(leads, ch))
-				addchr(leads, ch);
-		}
+		newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp);
 	}
 
 	/* and the ranges */
@@ -1681,103 +1515,9 @@ dovec(struct vars * v,
 	{
 		from = *p;
 		to = *(p + 1);
-		while (from <= to && (ce = nextleader(v, from, to)) != NOCELT)
-		{
-			if (from < ce)
-				subrange(v, from, ce - 1, lp, rp);
-			assert(singleton(v->cm, ce));
-			assert(leads != NULL);
-			if (!haschr(leads, ce))
-				addchr(leads, ce);
-			from = ce + 1;
-		}
 		if (from <= to)
 			subrange(v, from, to, lp, rp);
 	}
-
-	if ((leads == NULL || leads->nchrs == 0) && cv->nmcces == 0)
-		return;
-
-	/* deal with the MCCE leaders */
-	NOTE(REG_ULOCALE);
-	for (p = leads->chrs, i = leads->nchrs; i > 0; p++, i--)
-	{
-		co = GETCOLOR(v->cm, *p);
-		a = findarc(lp, PLAIN, co);
-		if (a != NULL)
-			s = a->to;
-		else
-		{
-			s = newstate(v->nfa);
-			NOERR();
-			newarc(v->nfa, PLAIN, co, lp, s);
-			NOERR();
-		}
-		pa = findarc(v->mccepbegin, PLAIN, co);
-		assert(pa != NULL);
-		ps = pa->to;
-		newarc(v->nfa, '$', 1, s, rp);
-		newarc(v->nfa, '$', 0, s, rp);
-		colorcomplement(v->nfa, v->cm, AHEAD, ps, s, rp);
-		NOERR();
-	}
-
-	/* and the MCCEs */
-	for (i = 0; i < cv->nmcces; i++)
-	{
-		p = cv->mcces[i];
-		assert(singleton(v->cm, *p));
-		if (!singleton(v->cm, *p))
-		{
-			ERR(REG_ASSERT);
-			return;
-		}
-		ch = *p++;
-		co = GETCOLOR(v->cm, ch);
-		a = findarc(lp, PLAIN, co);
-		if (a != NULL)
-			s = a->to;
-		else
-		{
-			s = newstate(v->nfa);
-			NOERR();
-			newarc(v->nfa, PLAIN, co, lp, s);
-			NOERR();
-		}
-		assert(*p != 0);		/* at least two chars */
-		assert(singleton(v->cm, *p));
-		ch = *p++;
-		co = GETCOLOR(v->cm, ch);
-		assert(*p == 0);		/* and only two, for now */
-		newarc(v->nfa, PLAIN, co, s, rp);
-		NOERR();
-	}
-}
-
-/*
- * nextleader - find next MCCE leader within range
- */
-static celt						/* NOCELT means none */
-nextleader(struct vars * v,
-		   chr from,
-		   chr to)
-{
-	int			i;
-	chr		   *p;
-	chr			ch;
-	celt		it = NOCELT;
-
-	if (v->mcces == NULL)
-		return it;
-
-	for (i = v->mcces->nchrs, p = v->mcces->chrs; i > 0; i--, p++)
-	{
-		ch = *p;
-		if (from <= ch && ch <= to)
-			if (it == NOCELT || ch < it)
-				it = ch;
-	}
-	return it;
 }
 
 /*
@@ -1825,9 +1565,8 @@ subre(struct vars * v,
 	  struct state * begin,
 	  struct state * end)
 {
-	struct subre *ret;
+	struct subre *ret = v->treefree;
 
-	ret = v->treefree;
 	if (ret != NULL)
 		v->treefree = ret->left;
 	else
@@ -1906,14 +1645,13 @@ static void
 optst(struct vars * v,
 	  struct subre * t)
 {
-	if (t == NULL)
-		return;
-
-	/* recurse through children */
-	if (t->left != NULL)
-		optst(v, t->left);
-	if (t->right != NULL)
-		optst(v, t->right);
+	/*
+	 * DGP (2007-11-13): I assume it was the programmer's intent to eventually
+	 * come back and add code to optimize subRE trees, but the routine coded
+	 * just spends effort traversing the tree and doing nothing. We can do
+	 * nothing with less effort.
+	 */
+	return;
 }
 
 /*
@@ -2207,8 +1945,8 @@ stdump(struct subre * t,
 	{
 		fprintf(f, "\n");
 		dumpcnfa(&t->cnfa, f);
-		fprintf(f, "\n");
 	}
+	fprintf(f, "\n");
 	if (t->left != NULL)
 		stdump(t->left, f, nfapresent);
 	if (t->right != NULL)
@@ -2218,7 +1956,7 @@ stdump(struct subre * t,
 /*
  * stid - identify a subtree node for dumping
  */
-static char *					/* points to buf or constant string */
+static const char *				/* points to buf or constant string */
 stid(struct subre * t,
 	 char *buf,
 	 size_t bufsize)
diff --git a/src/backend/regex/regerror.c b/src/backend/regex/regerror.c
index 3b20446350..dfcb462e01 100644
--- a/src/backend/regex/regerror.c
+++ b/src/backend/regex/regerror.c
@@ -27,7 +27,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/backend/regex/regerror.c,v 1.27 2003/11/29 19:51:55 pgsql Exp $
+ * $PostgreSQL: pgsql/src/backend/regex/regerror.c,v 1.28 2008/02/14 17:33:37 tgl Exp $
  *
  */
 
@@ -40,8 +40,8 @@ static char unk[] = "*** unknown regex error code 0x%x ***";
 static struct rerr
 {
 	int			code;
-	char	   *name;
-	char	   *explain;
+	const char *name;
+	const char *explain;
 }	rerrs[] =
 
 {
@@ -63,7 +63,7 @@ pg_regerror(int errcode,		/* error code, or REG_ATOI or REG_ITOA */
 			size_t errbuf_size) /* available space in errbuf, can be 0 */
 {
 	struct rerr *r;
-	char	   *msg;
+	const char *msg;
 	char		convbuf[sizeof(unk) + 50];		/* 50 = plenty for int */
 	size_t		len;
 	int			icode;
diff --git a/src/include/regex/regcustom.h b/src/include/regex/regcustom.h
index 8471fb0b1c..269f926be8 100644
--- a/src/include/regex/regcustom.h
+++ b/src/include/regex/regcustom.h
@@ -25,7 +25,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/include/regex/regcustom.h,v 1.6 2007/10/06 16:01:51 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/regex/regcustom.h,v 1.7 2008/02/14 17:33:37 tgl Exp $
  */
 
 /* headers if any */
@@ -47,9 +47,9 @@
 /* internal character type and related */
 typedef pg_wchar chr;			/* the type itself */
 typedef unsigned uchr;			/* unsigned type that will hold a chr */
-typedef int celt;				/* type to hold chr, MCCE number, or NOCELT */
+typedef int celt;				/* type to hold chr, or NOCELT */
 
-#define NOCELT	(-1)			/* celt value which is not valid chr or MCCE */
+#define NOCELT	(-1)			/* celt value which is not valid chr */
 #define CHR(c)	((unsigned char) (c))	/* turn char literal into chr literal */
 #define DIGITVAL(c) ((c)-'0')	/* turn chr digit into its value */
 #define CHRBITS 32				/* bits in a chr; must not use sizeof */
diff --git a/src/include/regex/regguts.h b/src/include/regex/regguts.h
index 327808338a..52f2157535 100644
--- a/src/include/regex/regguts.h
+++ b/src/include/regex/regguts.h
@@ -27,7 +27,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
- * $PostgreSQL: pgsql/src/include/regex/regguts.h,v 1.6 2008/01/03 20:47:55 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/regex/regguts.h,v 1.7 2008/02/14 17:33:37 tgl Exp $
  */
 
 
@@ -181,7 +181,7 @@ union tree
 #define tcolor	colors.ccolor
 #define tptr	ptrs.pptr
 
-/* internal per-color structure for the color machinery */
+/* internal per-color descriptor structure for the color machinery */
 struct colordesc
 {
 	uchr		nchrs;			/* number of chars of this color */
@@ -228,11 +228,11 @@ struct colormap
 #endif
 
 
-
 /*
  * Interface definitions for locale-interface functions in locale.c.
- * Multi-character collating elements (MCCEs) cause most of the trouble.
  */
+
+/* Representation of a set of characters. */
 struct cvec
 {
 	int			nchrs;			/* number of chrs */
@@ -241,17 +241,9 @@ struct cvec
 	int			nranges;		/* number of ranges (chr pairs) */
 	int			rangespace;		/* number of chrs possible */
 	chr		   *ranges;			/* pointer to vector of chr pairs */
-	int			nmcces;			/* number of MCCEs */
-	int			mccespace;		/* number of MCCEs possible */
-	int			nmccechrs;		/* number of chrs used for MCCEs */
-	chr		   *mcces[1];		/* pointers to 0-terminated MCCEs */
-	/* and both batches of chrs are on the end */
+	/* both batches of chrs are on the end */
 };
 
-/* caution:  this value cannot be changed easily */
-#define MAXMCCE 2				/* length of longest MCCE */
-
-
 
 /*
  * definitions for NFA internal representation
-- 
2.40.0