From 79af9a1d2668c9edc8171f03c39e7fed571eeb98 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Tue, 6 Jan 2015 23:06:13 -0500 Subject: [PATCH] Fix namespace handling in xpath function Previously, the xml value resulting from an xpath query would not have namespace declarations if the namespace declarations were attached to an ancestor element in the input xml value. That means the output value was not correct XML. Fix that by running the result value through xmlCopyNode(), which produces the correct namespace declarations. Author: Ali Akbar --- src/backend/utils/adt/xml.c | 34 ++++++++++++++++++++++------- src/test/regress/expected/xml.out | 15 +++++++++++++ src/test/regress/expected/xml_1.out | 12 ++++++++++ src/test/regress/sql/xml.sql | 2 ++ 4 files changed, 55 insertions(+), 8 deletions(-) diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c index a735aa2801..bfe9447295 100644 --- a/src/backend/utils/adt/xml.c +++ b/src/backend/utils/adt/xml.c @@ -141,9 +141,10 @@ static bool print_xml_decl(StringInfo buf, const xmlChar *version, pg_enc encoding, int standalone); static xmlDocPtr xml_parse(text *data, XmlOptionType xmloption_arg, bool preserve_whitespace, int encoding); -static text *xml_xmlnodetoxmltype(xmlNodePtr cur); +static text *xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt); static int xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj, - ArrayBuildState *astate); + ArrayBuildState *astate, + PgXmlErrorContext *xmlerrcxt); #endif /* USE_LIBXML */ static StringInfo query_to_xml_internal(const char *query, char *tablename, @@ -3599,26 +3600,41 @@ SPI_sql_row_to_xmlelement(int rownum, StringInfo result, char *tablename, * return value otherwise) */ static text * -xml_xmlnodetoxmltype(xmlNodePtr cur) +xml_xmlnodetoxmltype(xmlNodePtr cur, PgXmlErrorContext *xmlerrcxt) { xmltype *result; if (cur->type == XML_ELEMENT_NODE) { xmlBufferPtr buf; + xmlNodePtr cur_copy; buf = xmlBufferCreate(); + + /* + * The result of xmlNodeDump() won't contain namespace definitions + * from parent nodes, but xmlCopyNode() duplicates a node along with + * its required namespace definitions. + */ + cur_copy = xmlCopyNode(cur, 1); + + if (cur_copy == NULL) + xml_ereport(xmlerrcxt, ERROR, ERRCODE_OUT_OF_MEMORY, + "could not copy node"); + PG_TRY(); { - xmlNodeDump(buf, NULL, cur, 0, 1); + xmlNodeDump(buf, NULL, cur_copy, 0, 1); result = xmlBuffer_to_xmltype(buf); } PG_CATCH(); { + xmlFreeNode(cur_copy); xmlBufferFree(buf); PG_RE_THROW(); } PG_END_TRY(); + xmlFreeNode(cur_copy); xmlBufferFree(buf); } else @@ -3660,7 +3676,8 @@ xml_xmlnodetoxmltype(xmlNodePtr cur) */ static int xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj, - ArrayBuildState *astate) + ArrayBuildState *astate, + PgXmlErrorContext *xmlerrcxt) { int result = 0; Datum datum; @@ -3679,7 +3696,8 @@ xml_xpathobjtoxmlarray(xmlXPathObjectPtr xpathobj, for (i = 0; i < result; i++) { - datum = PointerGetDatum(xml_xmlnodetoxmltype(xpathobj->nodesetval->nodeTab[i])); + datum = PointerGetDatum(xml_xmlnodetoxmltype(xpathobj->nodesetval->nodeTab[i], + xmlerrcxt)); (void) accumArrayResult(astate, datum, false, XMLOID, CurrentMemoryContext); } @@ -3881,9 +3899,9 @@ xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces, * Extract the results as requested. */ if (res_nitems != NULL) - *res_nitems = xml_xpathobjtoxmlarray(xpathobj, astate); + *res_nitems = xml_xpathobjtoxmlarray(xpathobj, astate, xmlerrcxt); else - (void) xml_xpathobjtoxmlarray(xpathobj, astate); + (void) xml_xpathobjtoxmlarray(xpathobj, astate, xmlerrcxt); } PG_CATCH(); { diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out index 6e6c673dac..9b2d264414 100644 --- a/src/test/regress/expected/xml.out +++ b/src/test/regress/expected/xml.out @@ -612,6 +612,21 @@ SELECT xpath('//loc:piece/@id', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); + xpath +------------------------------------------------------------------------------------------------------------------------------------------------ + {"number one",""} +(1 row) + +SELECT xpath('//loc:piece', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); + xpath +-------------------------------------------------------------------------------------- + {"+ + number one + + + + ",""} +(1 row) + SELECT xpath('//b', 'one two three etc'); xpath ------------------------- diff --git a/src/test/regress/expected/xml_1.out b/src/test/regress/expected/xml_1.out index b0e00671e8..c7fa526f9c 100644 --- a/src/test/regress/expected/xml_1.out +++ b/src/test/regress/expected/xml_1.out @@ -514,6 +514,18 @@ LINE 1: SELECT xpath('//loc:piece/@id', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); +ERROR: unsupported XML feature +LINE 1: SELECT xpath('//loc:piece', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); +ERROR: unsupported XML feature +LINE 1: SELECT xpath('//loc:piece', 'number one'); SELECT xpath('//loc:piece/@id', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); +SELECT xpath('//loc:piece', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); +SELECT xpath('//loc:piece', 'number one', ARRAY[ARRAY['loc', 'http://127.0.0.1']]); SELECT xpath('//b', 'one two three etc'); SELECT xpath('//text()', '<'); SELECT xpath('//@value', '');