>
> Isn't the most correct solution to call xml_parse function?
>
I am reply to self. Probably not.
Now, I am thinking so I found a reason of this issue. The document
processed in xpath_internal is passed to libXML2 by
doc = xmlCtxtReadMemory(ctxt, (char *) string, len, NULL, NULL, 0);
We don't pass a encoding parameter so libXML2 expecting "UTF8" or expecting
correct encoding decl in XML document. When we pass incorrect document -
XML is in database encoding, but encoding decl is original, then it should
to fail.
the regress test can looks like your (but all chars are valid there)
postgres=# do $$
declare str text;
begin
if current_setting('server_encoding') <> 'UTF8' then return; end if;
str = '<?xml version="1.0"
encoding="windows-1250"?><enprimeur><vino><id>909</id><remark>'
|| convert_from('\xc588', 'UTF8')
|| '</remark></vino></enprimeur>';
raise notice '%', xpath('/enprimeur/vino/id', str::xml);
end; $$;
ERROR: could not parse XML document
DETAIL: input conversion failed due to input error, bytes 0x88 0x3C 0x2F
0x72
line 1: switching encoding: encoder error
�</remark></vino></enprimeur>
^
CONTEXT: PL/pgSQL function inline_code_block line 8 at RAISE
After correct fix:
doc = xmlCtxtReadMemory(ctxt, (char *) string, len, NULL,
pg_encoding_to_char(GetDatabaseEncoding()),
0);
It is working
postgres=# do $$
declare str text;
begin
if current_setting('server_encoding') <> 'UTF8' then return; end if;
str = '<?xml version="1.0"
encoding="windows-1250"?><enprimeur><vino><id>909</id><remark>'
|| convert_from('\xc588', 'UTF8')
|| '</remark></vino></enprimeur>';
raise notice '%', xpath('/enprimeur/vino/id', str::xml);
end; $$;
NOTICE: {<id>909</id>}
DO
This fix should be apply to xmltable function too.
patch attached
It doesn't fix xpath and xmltable functions issues when server encoding is
not UTF8. Looks so XPath functions from libXML2 requires UTF8 encoded
strings and the result is in UTF8 too - so result should be recoded to
server encoding.
I didn't find any info how to enable libXML2 XPath functions for other
encoding than UTF8 :( ??
Regards
Pavel
> Regards
>
> Pavel
>
diff --git a/src/backend/utils/adt/xml.c b/src/backend/utils/adt/xml.c
index c47624eff6..b09ce23cdb 100644
--- a/src/backend/utils/adt/xml.c
+++ b/src/backend/utils/adt/xml.c
@@ -3911,7 +3911,9 @@ xpath_internal(text *xpath_expr_text, xmltype *data, ArrayType *namespaces,
if (ctxt == NULL || xmlerrcxt->err_occurred)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_OUT_OF_MEMORY,
"could not allocate parser context");
- doc = xmlCtxtReadMemory(ctxt, (char *) string, len, NULL, NULL, 0);
+ doc = xmlCtxtReadMemory(ctxt, (char *) string, len, NULL,
+ pg_encoding_to_char(GetDatabaseEncoding()), 0);
+
if (doc == NULL || xmlerrcxt->err_occurred)
xml_ereport(xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT,
"could not parse XML document");
@@ -4242,18 +4244,14 @@ XmlTableSetDocument(TableFuncScanState *state, Datum value)
xtCxt = GetXmlTableBuilderPrivateData(state, "XmlTableSetDocument");
- /*
- * Use out function for casting to string (remove encoding property). See
- * comment in xml_out.
- */
- str = xml_out_internal(xmlval, 0);
-
- length = strlen(str);
+ str = VARDATA(xmlval);
+ length = VARSIZE(xmlval) - VARHDRSZ;
xstr = pg_xmlCharStrndup(str, length);
PG_TRY();
{
- doc = xmlCtxtReadMemory(xtCxt->ctxt, (char *) xstr, length, NULL, NULL, 0);
+ doc = xmlCtxtReadMemory(xtCxt->ctxt, (char *) xstr, length, NULL,
+ pg_encoding_to_char(GetDatabaseEncoding()), 0);
if (doc == NULL || xtCxt->xmlerrcxt->err_occurred)
xml_ereport(xtCxt->xmlerrcxt, ERROR, ERRCODE_INVALID_XML_DOCUMENT,
"could not parse XML document");
diff --git a/src/test/regress/expected/xml.out b/src/test/regress/expected/xml.out
index bcc585d427..6a43896d40 100644
--- a/src/test/regress/expected/xml.out
+++ b/src/test/regress/expected/xml.out
@@ -1452,3 +1452,24 @@ SELECT xmltable.* FROM xmltest2, LATERAL xmltable(('/d/r/' || lower(_path) || 'c
14
(4 rows)
+-- XML is saved in database encoding with original encoding declaration.
+-- There can be incosistency based on wrong user input, different server/client
+-- encoding or reading XML with recv function. All XML functions should to
+-- work with this partially broken XML.
+DO $$
+DECLARE str text;
+BEGIN
+ -- leave early without error, when we are not sure about result of conversion
+ IF current_setting('server_encoding') NOT IN ('UTF8', 'LATIN2') THEN return; END IF;
+
+ -- build valid UTF8 XML with broken encoding declaration
+ str = '<?xml version="1.0" encoding="windows-1250"?><enprimeur><vino><id>909</id><remark>'
+ || convert_from('\xf2', 'windows-1250')
+ || '</remark></vino></enprimeur>';
+
+ -- should to work
+ RAISE NOTICE '%', xpath('/enprimeur/vino/id', str::xml);
+ RAISE NOTICE '%', (SELECT id FROM xmltable('/enprimeur/vino' PASSING (str::xml) COLUMNS id int));
+END; $$;
+NOTICE: {<id>909</id>}
+NOTICE: 909
diff --git a/src/test/regress/sql/xml.sql b/src/test/regress/sql/xml.sql
index eb4687fb09..97a3aa9de2 100644
--- a/src/test/regress/sql/xml.sql
+++ b/src/test/regress/sql/xml.sql
@@ -558,3 +558,23 @@ INSERT INTO xmltest2 VALUES('<d><r><dc>2</dc></r></d>', 'D');
SELECT xmltable.* FROM xmltest2, LATERAL xmltable('/d/r' PASSING x COLUMNS a int PATH '' || lower(_path) || 'c');
SELECT xmltable.* FROM xmltest2, LATERAL xmltable(('/d/r/' || lower(_path) || 'c') PASSING x COLUMNS a int PATH '.');
SELECT xmltable.* FROM xmltest2, LATERAL xmltable(('/d/r/' || lower(_path) || 'c') PASSING x COLUMNS a int PATH 'x' DEFAULT ascii(_path) - 54);
+
+-- XML is saved in database encoding with original encoding declaration.
+-- There can be incosistency based on wrong user input, different server/client
+-- encoding or reading XML with recv function. All XML functions should to
+-- work with this partially broken XML.
+DO $$
+DECLARE str text;
+BEGIN
+ -- leave early without error, when we are not sure about result of conversion
+ IF current_setting('server_encoding') NOT IN ('UTF8', 'LATIN2') THEN return; END IF;
+
+ -- build valid UTF8 XML with broken encoding declaration
+ str = '<?xml version="1.0" encoding="windows-1250"?><enprimeur><vino><id>909</id><remark>'
+ || convert_from('\xf2', 'windows-1250')
+ || '</remark></vino></enprimeur>';
+
+ -- should to work
+ RAISE NOTICE '%', xpath('/enprimeur/vino/id', str::xml);
+ RAISE NOTICE '%', (SELECT id FROM xmltable('/enprimeur/vino' PASSING (str::xml) COLUMNS id int));
+END; $$;
--
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