Make casts from xml to text independent of the XML option setting, thus

immutable and indexable.  Also fix the volatility settings of some other
XML-related functions.

src/backend/utils/adt/xml.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.60 2007/11/25 12:08:11 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/xml.c,v 1.61 2007/11/27 12:21:05 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -535,7 +535,8 @@ xmltotext(PG_FUNCTION_ARGS)
 {
 	xmltype    *data = PG_GETARG_XML_P(0);
 
-	PG_RETURN_TEXT_P(xmltotext_with_xmloption(data, xmloption));
+	/* It's actually binary compatible. */
+	return (text *) data;
 }
 
 

src/include/catalog/catversion.h

@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.437 2007/10/24 02:24:47 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.438 2007/11/27 12:21:05 petere Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200710232
+#define CATALOG_VERSION_NO	200711271
 
 #endif

src/include/catalog/pg_cast.h

@@ -10,7 +10,7 @@
  *
  * Copyright (c) 2002-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_cast.h,v 1.36 2007/11/15 21:14:42 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_cast.h,v 1.37 2007/11/27 12:21:05 petere Exp $
  *
  * NOTES
  *	  the genbki.sh script reads this file and generates .bki
@@ -292,7 +292,7 @@ DATA(insert ( 1560	 23 1684 e ));
 DATA(insert (  650	 25  730 a ));
 DATA(insert (  869	 25  730 a ));
 DATA(insert (	16	 25 2971 a ));
-DATA(insert (  142	 25 2922 a ));
+DATA(insert (  142	 25    0 a ));
 DATA(insert (	25	142 2896 e ));
 
 /*
@@ -303,7 +303,7 @@ DATA(insert (	25	142 2896 e ));
 DATA(insert (  650 1043  730 a ));
 DATA(insert (  869 1043  730 a ));
 DATA(insert (	16 1043 2971 a ));
-DATA(insert (  142 1043 2922 a ));
+DATA(insert (  142 1043    0 a ));
 DATA(insert ( 1043	142 2896 e ));
 
 /*
@@ -314,7 +314,7 @@ DATA(insert ( 1043	142 2896 e ));
 DATA(insert (  650 1042  730 a ));
 DATA(insert (  869 1042  730 a ));
 DATA(insert (	16 1042 2971 a ));
-DATA(insert (  142 1042 2922 a ));
+DATA(insert (  142 1042    0 a ));
 DATA(insert ( 1042	142 2896 e ));
 
 /*

src/include/catalog/pg_proc.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.478 2007/11/15 21:14:43 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/pg_proc.h,v 1.479 2007/11/27 12:21:05 petere Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -4028,13 +4028,13 @@ DATA(insert OID = 2892 (  pg_advisory_unlock_all		PGNSP PGUID 12 1 0 f f t f v 0
 DESCR("release all advisory locks");
 
 /* XML support */
-DATA(insert OID = 2893 (  xml_in		   PGNSP PGUID 12 1 0 f f t f i 1 142 "2275" _null_ _null_ _null_ xml_in - _null_ _null_ ));
+DATA(insert OID = 2893 (  xml_in		   PGNSP PGUID 12 1 0 f f t f s 1 142 "2275" _null_ _null_ _null_ xml_in - _null_ _null_ ));
 DESCR("I/O");
 DATA(insert OID = 2894 (  xml_out		   PGNSP PGUID 12 1 0 f f t f i 1 2275 "142" _null_ _null_ _null_ xml_out - _null_ _null_ ));
 DESCR("I/O");
 DATA(insert OID = 2895 (  xmlcomment	   PGNSP PGUID 12 1 0 f f t f i 1 142 "25" _null_ _null_ _null_ xmlcomment - _null_ _null_ ));
 DESCR("generate an XML comment");
-DATA(insert OID = 2896 (  xml			   PGNSP PGUID 12 1 0 f f t f i 1 142 "25" _null_ _null_ _null_ texttoxml - _null_ _null_ ));
+DATA(insert OID = 2896 (  xml			   PGNSP PGUID 12 1 0 f f t f s 1 142 "25" _null_ _null_ _null_ texttoxml - _null_ _null_ ));
 DESCR("perform a non-validating parse of a character string to produce an XML value");
 DATA(insert OID = 2897 (  xmlvalidate	   PGNSP PGUID 12 1 0 f f t f i 2 16 "142 25" _null_ _null_ _null_ xmlvalidate - _null_ _null_ ));
 DESCR("validate an XML value");
@@ -4046,7 +4046,7 @@ DATA(insert OID = 2900 (  xmlconcat2	   PGNSP PGUID 12 1 0 f f f f i 2 142 "142
 DESCR("aggregate transition function");
 DATA(insert OID = 2901 (  xmlagg		   PGNSP PGUID 12 1 0 t f f f i 1 142 "142" _null_ _null_ _null_ aggregate_dummy - _null_ _null_ ));
 DESCR("concatenate XML values");
-DATA(insert OID = 2922 (  text			   PGNSP PGUID 12 1 0 f f t f s 1 25 "142" _null_ _null_ _null_ xmltotext - _null_ _null_ ));
+DATA(insert OID = 2922 (  text			   PGNSP PGUID 12 1 0 f f t f i 1 25 "142" _null_ _null_ _null_ xmltotext - _null_ _null_ ));
 DESCR("serialize an XML value to a character string");
 
 DATA(insert OID = 2923 (  table_to_xml				  PGNSP PGUID 12 100 0 f f t f s 4 142 "2205 16 16 25" _null_ _null_ "{tbl,nulls,tableforest,targetns}" table_to_xml - _null_ _null_ ));

src/test/regress/expected/opr_sanity.out

@@ -288,6 +288,9 @@ WHERE c.castfunc = p.oid AND
 -- those are binary-compatible while the reverse way goes through rtrim().
 -- As of 8.2, this finds the cast from cidr to inet, because that is a
 -- trivial binary coercion while the other way goes through inet_to_cidr().
+-- As of 8.3, this finds the casts from xml to text, varchar, and bpchar,
+-- because those are binary-compatible while the reverse goes through
+-- texttoxml(), which does an XML syntax check.
 SELECT *
 FROM pg_cast c
 WHERE c.castfunc = 0 AND
@@ -300,7 +303,10 @@ WHERE c.castfunc = 0 AND
          25 |       1042 |        0 | i
        1043 |       1042 |        0 | i
         650 |        869 |        0 | i
-(3 rows)
+        142 |         25 |        0 | a
+        142 |       1043 |        0 | a
+        142 |       1042 |        0 | a
+(6 rows)
 
 -- **************** pg_operator ****************
 -- Look for illegal values in pg_operator fields.

src/test/regress/sql/opr_sanity.sql

@@ -238,6 +238,10 @@ WHERE c.castfunc = p.oid AND
 -- As of 8.2, this finds the cast from cidr to inet, because that is a
 -- trivial binary coercion while the other way goes through inet_to_cidr().
 
+-- As of 8.3, this finds the casts from xml to text, varchar, and bpchar,
+-- because those are binary-compatible while the reverse goes through
+-- texttoxml(), which does an XML syntax check.
+
 SELECT *
 FROM pg_cast c
 WHERE c.castfunc = 0 AND