Merge commit 'a4bebdd92624e018108c2610fc3f2c1584b6c687' into master

This is the commit merge of Postgres-XC with the intersection of
PostgreSQL REL9_1_STABLE and master branches.

Conflicts:
	COPYRIGHT
	contrib/pgbench/pgbench.c
	src/Makefile
	src/backend/access/transam/recovery.conf.sample
	src/backend/access/transam/varsup.c
	src/backend/access/transam/xlog.c
	src/backend/catalog/Makefile
	src/backend/catalog/dependency.c
	src/backend/catalog/system_views.sql
	src/backend/commands/copy.c
	src/backend/commands/explain.c
	src/backend/commands/sequence.c
	src/backend/commands/tablecmds.c
	src/backend/commands/vacuum.c
	src/backend/executor/nodeAgg.c
	src/backend/nodes/copyfuncs.c
	src/backend/nodes/equalfuncs.c
	src/backend/nodes/outfuncs.c
	src/backend/nodes/readfuncs.c
	src/backend/optimizer/path/allpaths.c
	src/backend/optimizer/plan/createplan.c
	src/backend/optimizer/plan/setrefs.c
	src/backend/parser/gram.y
	src/backend/parser/parse_utilcmd.c
	src/backend/postmaster/postmaster.c
	src/backend/rewrite/rewriteHandler.c
	src/backend/storage/lmgr/proc.c
	src/backend/tcop/postgres.c
	src/backend/utils/adt/ruleutils.c
	src/backend/utils/init/postinit.c
	src/backend/utils/misc/guc.c
	src/backend/utils/misc/postgresql.conf.sample
	src/backend/utils/sort/tuplesort.c
	src/bin/initdb/initdb.c
	src/bin/pg_ctl/pg_ctl.c
	src/bin/pg_dump/pg_dump.c
	src/include/access/xlog.h
	src/include/catalog/catversion.h
	src/include/catalog/indexing.h
	src/include/catalog/pg_aggregate.h
	src/include/catalog/pg_proc.h
	src/include/commands/copy.h
	src/include/nodes/parsenodes.h
	src/include/nodes/primnodes.h
	src/include/optimizer/pathnode.h
	src/include/parser/kwlist.h
	src/include/storage/procarray.h
	src/test/regress/expected/.gitignore
	src/test/regress/expected/aggregates.out
	src/test/regress/expected/alter_table.out
	src/test/regress/expected/bit.out
	src/test/regress/expected/box.out
	src/test/regress/expected/delete.out
	src/test/regress/expected/float4.out
	src/test/regress/expected/float8.out
	src/test/regress/expected/int2.out
	src/test/regress/expected/int8.out
	src/test/regress/expected/interval.out
	src/test/regress/expected/numeric.out
	src/test/regress/expected/point.out
	src/test/regress/expected/polygon.out
	src/test/regress/expected/sequence.out
	src/test/regress/expected/timestamp.out
	src/test/regress/expected/timestamptz.out
	src/test/regress/expected/transactions.out
	src/test/regress/expected/window.out
	src/test/regress/input/misc.source
	src/test/regress/output/create_misc_1.source
	src/test/regress/output/misc.source
	src/test/regress/sql/aggregates.sql
	src/test/regress/sql/alter_table.sql
	src/test/regress/sql/bit.sql
	src/test/regress/sql/box.sql
	src/test/regress/sql/delete.sql
	src/test/regress/sql/domain.sql
	src/test/regress/sql/float4.sql
	src/test/regress/sql/float8.sql
	src/test/regress/sql/int2.sql
	src/test/regress/sql/int8.sql
	src/test/regress/sql/interval.sql
	src/test/regress/sql/lseg.sql
	src/test/regress/sql/numeric.sql
	src/test/regress/sql/path.sql
	src/test/regress/sql/point.sql
	src/test/regress/sql/polygon.sql
	src/test/regress/sql/portals.sql
	src/test/regress/sql/sequence.sql
	src/test/regress/sql/timestamp.sql
	src/test/regress/sql/timestamptz.sql
	src/test/regress/sql/transactions.sql
	src/test/regress/sql/window.sql
	src/test/regress/sql/with.sql

1 files changed, 99 insertions, 74 deletions

diff --git a/contrib/xml2/xpath.c b/contrib/xml2/xpath.c
index dbf0b76f92..44c600e134 100644
--- a/contrib/xml2/xpath.c
+++ b/contrib/xml2/xpath.c
@@ -1,5 +1,5 @@
 /*
- * $PostgreSQL: pgsql/contrib/xml2/xpath.c,v 1.30 2010/07/06 19:18:55 momjian Exp $
+ * contrib/xml2/xpath.c
  *
  * Parser interface for DOM-based parser (libxml) rather than
  * stream-based SAX-type parser
@@ -40,6 +40,15 @@ Datum		xpath_table(PG_FUNCTION_ARGS);
 
 void		pgxml_parser_init(void);
 
+/* workspace for pgxml_xpath() */
+
+typedef struct
+{
+	xmlDocPtr	doctree;
+	xmlXPathContextPtr ctxt;
+	xmlXPathObjectPtr res;
+} xpath_workspace;
+
 /* local declarations */
 
 static xmlChar *pgxmlNodeSetToText(xmlNodeSetPtr nodeset,
@@ -51,7 +60,10 @@ static text *pgxml_result_to_text(xmlXPathObjectPtr res, xmlChar *toptag,
 
 static xmlChar *pgxml_texttoxmlchar(text *textstring);
 
-static xmlXPathObjectPtr pgxml_xpath(text *document, xmlChar *xpath);
+static xmlXPathObjectPtr pgxml_xpath(text *document, xmlChar *xpath,
+			xpath_workspace *workspace);
+
+static void cleanup_workspace(xpath_workspace *workspace);
 
 
 /*
@@ -71,7 +83,14 @@ pgxml_parser_init(void)
 }
 
 
-/* Returns true if document is well-formed */
+/*
+ * Returns true if document is well-formed
+ *
+ * Note: this has been superseded by a core function.  We still have to
+ * have it in the contrib module so that existing SQL-level references
+ * to the function won't fail; but in normal usage with up-to-date SQL
+ * definitions for the contrib module, this won't be called.
+ */
 
 PG_FUNCTION_INFO_V1(xml_is_well_formed);
 
@@ -214,25 +233,22 @@ PG_FUNCTION_INFO_V1(xpath_nodeset);
 Datum
 xpath_nodeset(PG_FUNCTION_ARGS)
 {
-	xmlChar    *xpath,
-			   *toptag,
-			   *septag;
-	int32		pathsize;
-	text	   *xpathsupp,
-			   *xpres;
-
-	/* PG_GETARG_TEXT_P(0) is document buffer */
-	xpathsupp = PG_GETARG_TEXT_P(1);	/* XPath expression */
+	text	   *document = PG_GETARG_TEXT_P(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_P(1);		/* XPath expression */
+	xmlChar    *toptag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
+	xmlChar    *septag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(3));
+	xmlChar    *xpath;
+	text	   *xpres;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
 
-	toptag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
-	septag = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(3));
+	xpath = pgxml_texttoxmlchar(xpathsupp);
 
-	pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+	res = pgxml_xpath(document, xpath, &workspace);
 
-	xpath = pgxml_texttoxmlchar(xpathsupp);
+	xpres = pgxml_result_to_text(res, toptag, septag, NULL);
 
-	xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
-								 toptag, septag, NULL);
+	cleanup_workspace(&workspace);
 
 	pfree(xpath);
 
@@ -250,23 +266,21 @@ PG_FUNCTION_INFO_V1(xpath_list);
 Datum
 xpath_list(PG_FUNCTION_ARGS)
 {
-	xmlChar    *xpath,
-			   *plainsep;
-	int32		pathsize;
-	text	   *xpathsupp,
-			   *xpres;
-
-	/* PG_GETARG_TEXT_P(0) is document buffer */
-	xpathsupp = PG_GETARG_TEXT_P(1);	/* XPath expression */
+	text	   *document = PG_GETARG_TEXT_P(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_P(1);		/* XPath expression */
+	xmlChar    *plainsep = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
+	xmlChar    *xpath;
+	text	   *xpres;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
 
-	plainsep = pgxml_texttoxmlchar(PG_GETARG_TEXT_P(2));
+	xpath = pgxml_texttoxmlchar(xpathsupp);
 
-	pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+	res = pgxml_xpath(document, xpath, &workspace);
 
-	xpath = pgxml_texttoxmlchar(xpathsupp);
+	xpres = pgxml_result_to_text(res, NULL, NULL, plainsep);
 
-	xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
-								 NULL, NULL, plainsep);
+	cleanup_workspace(&workspace);
 
 	pfree(xpath);
 
@@ -281,13 +295,13 @@ PG_FUNCTION_INFO_V1(xpath_string);
 Datum
 xpath_string(PG_FUNCTION_ARGS)
 {
+	text	   *document = PG_GETARG_TEXT_P(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_P(1);		/* XPath expression */
 	xmlChar    *xpath;
 	int32		pathsize;
-	text	   *xpathsupp,
-			   *xpres;
-
-	/* PG_GETARG_TEXT_P(0) is document buffer */
-	xpathsupp = PG_GETARG_TEXT_P(1);	/* XPath expression */
+	text	   *xpres;
+	xmlXPathObjectPtr res;
+	xpath_workspace workspace;
 
 	pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
 
@@ -298,13 +312,16 @@ xpath_string(PG_FUNCTION_ARGS)
 	/* We could try casting to string using the libxml function? */
 
 	xpath = (xmlChar *) palloc(pathsize + 9);
-	memcpy((char *) (xpath + 7), VARDATA(xpathsupp), pathsize);
 	strncpy((char *) xpath, "string(", 7);
+	memcpy((char *) (xpath + 7), VARDATA(xpathsupp), pathsize);
 	xpath[pathsize + 7] = ')';
 	xpath[pathsize + 8] = '\0';
 
-	xpres = pgxml_result_to_text(pgxml_xpath(PG_GETARG_TEXT_P(0), xpath),
-								 NULL, NULL, NULL);
+	res = pgxml_xpath(document, xpath, &workspace);
+
+	xpres = pgxml_result_to_text(res, NULL, NULL, NULL);
+
+	cleanup_workspace(&workspace);
 
 	pfree(xpath);
 
@@ -319,21 +336,17 @@ PG_FUNCTION_INFO_V1(xpath_number);
 Datum
 xpath_number(PG_FUNCTION_ARGS)
 {
+	text	   *document = PG_GETARG_TEXT_P(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_P(1);		/* XPath expression */
 	xmlChar    *xpath;
-	int32		pathsize;
-	text	   *xpathsupp;
 	float4		fRes;
-
 	xmlXPathObjectPtr res;
-
-	/* PG_GETARG_TEXT_P(0) is document buffer */
-	xpathsupp = PG_GETARG_TEXT_P(1);	/* XPath expression */
-
-	pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+	xpath_workspace workspace;
 
 	xpath = pgxml_texttoxmlchar(xpathsupp);
 
-	res = pgxml_xpath(PG_GETARG_TEXT_P(0), xpath);
+	res = pgxml_xpath(document, xpath, &workspace);
+
 	pfree(xpath);
 
 	if (res == NULL)
@@ -341,6 +354,8 @@ xpath_number(PG_FUNCTION_ARGS)
 
 	fRes = xmlXPathCastToNumber(res);
 
+	cleanup_workspace(&workspace);
+
 	if (xmlXPathIsNaN(fRes))
 		PG_RETURN_NULL();
 
@@ -353,21 +368,17 @@ PG_FUNCTION_INFO_V1(xpath_bool);
 Datum
 xpath_bool(PG_FUNCTION_ARGS)
 {
+	text	   *document = PG_GETARG_TEXT_P(0);
+	text	   *xpathsupp = PG_GETARG_TEXT_P(1);		/* XPath expression */
 	xmlChar    *xpath;
-	int32		pathsize;
-	text	   *xpathsupp;
 	int			bRes;
-
 	xmlXPathObjectPtr res;
-
-	/* PG_GETARG_TEXT_P(0) is document buffer */
-	xpathsupp = PG_GETARG_TEXT_P(1);	/* XPath expression */
-
-	pathsize = VARSIZE(xpathsupp) - VARHDRSZ;
+	xpath_workspace workspace;
 
 	xpath = pgxml_texttoxmlchar(xpathsupp);
 
-	res = pgxml_xpath(PG_GETARG_TEXT_P(0), xpath);
+	res = pgxml_xpath(document, xpath, &workspace);
+
 	pfree(xpath);
 
 	if (res == NULL)
@@ -375,6 +386,8 @@ xpath_bool(PG_FUNCTION_ARGS)
 
 	bRes = xmlXPathCastToBoolean(res);
 
+	cleanup_workspace(&workspace);
+
 	PG_RETURN_BOOL(bRes);
 }
 
@@ -383,49 +396,61 @@ xpath_bool(PG_FUNCTION_ARGS)
 /* Core function to evaluate XPath query */
 
 static xmlXPathObjectPtr
-pgxml_xpath(text *document, xmlChar *xpath)
+pgxml_xpath(text *document, xmlChar *xpath, xpath_workspace *workspace)
 {
-	xmlDocPtr	doctree;
-	xmlXPathContextPtr ctxt;
+	int32		docsize = VARSIZE(document) - VARHDRSZ;
 	xmlXPathObjectPtr res;
 	xmlXPathCompExprPtr comppath;
-	int32		docsize;
 
-	docsize = VARSIZE(document) - VARHDRSZ;
+	workspace->doctree = NULL;
+	workspace->ctxt = NULL;
+	workspace->res = NULL;
 
 	pgxml_parser_init();
 
-	doctree = xmlParseMemory((char *) VARDATA(document), docsize);
-	if (doctree == NULL)
+	workspace->doctree = xmlParseMemory((char *) VARDATA(document), docsize);
+	if (workspace->doctree == NULL)
 		return NULL;			/* not well-formed */
 
-	ctxt = xmlXPathNewContext(doctree);
-	ctxt->node = xmlDocGetRootElement(doctree);
+	workspace->ctxt = xmlXPathNewContext(workspace->doctree);
+	workspace->ctxt->node = xmlDocGetRootElement(workspace->doctree);
 
 	/* compile the path */
 	comppath = xmlXPathCompile(xpath);
 	if (comppath == NULL)
 	{
-		xmlFreeDoc(doctree);
+		cleanup_workspace(workspace);
 		xml_ereport(ERROR, ERRCODE_EXTERNAL_ROUTINE_EXCEPTION,
 					"XPath Syntax Error");
 	}
 
 	/* Now evaluate the path expression. */
-	res = xmlXPathCompiledEval(comppath, ctxt);
+	res = xmlXPathCompiledEval(comppath, workspace->ctxt);
+	workspace->res = res;
+
 	xmlXPathFreeCompExpr(comppath);
 
 	if (res == NULL)
-	{
-		xmlXPathFreeContext(ctxt);
-		xmlFreeDoc(doctree);
+		cleanup_workspace(workspace);
 
-		return NULL;
-	}
-	/* xmlFreeDoc(doctree); */
 	return res;
 }
 
+/* Clean up after processing the result of pgxml_xpath() */
+static void
+cleanup_workspace(xpath_workspace *workspace)
+{
+	if (workspace->res)
+		xmlXPathFreeObject(workspace->res);
+	workspace->res = NULL;
+	if (workspace->ctxt)
+		xmlXPathFreeContext(workspace->ctxt);
+	workspace->ctxt = NULL;
+	if (workspace->doctree)
+		xmlFreeDoc(workspace->doctree);
+	workspace->doctree = NULL;
+}
+
 static text *
 pgxml_result_to_text(xmlXPathObjectPtr res,
 					 xmlChar *toptag,