It appears that libxml2 doesn't bother to set the "children" field of
an XML_NAMESPACE_DECL node to null; that field just contains garbage.
In v10 and v11, this can result in a crash in XMLTABLE(). The rewrite
done in commit
251cf2e27 fixed this, somewhat accidentally, in v12.
We're not going to back-patch
251cf2e27, however. The case apparently
doesn't have wide use, so rather than risk introducing other problems,
just add a safety check to throw an error.
Even though no bug manifests in v12/HEAD, add the relevant test case
there too, to prevent future regressions.
Chapman Flack (per private report)
xmlChar *str;
xmlNodePtr node;
+ node = xpathobj->nodesetval->nodeTab[0];
+ if (node->type == XML_NAMESPACE_DECL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("XMLTABLE cannot cast a namespace node to a non-XML result type")));
+
/*
* Most nodes (elements and even attributes) store their data
* in children nodes. If they don't have children nodes, it
* CDATA sections are an exception: they don't have children
* but have content in the Text/CDATA node itself.
*/
- node = xpathobj->nodesetval->nodeTab[0];
if (node->type != XML_CDATA_SECTION_NODE &&
node->type != XML_TEXT_NODE)
node = node->xmlChildrenNode;
PASSING '<rows xmlns="http://x.y"><row><a>10</a></row></rows>'
COLUMNS a int PATH 'a');
ERROR: DEFAULT namespace is not supported
+SELECT * FROM XMLTABLE('/'
+ PASSING '<foo/>'
+ COLUMNS a text PATH 'foo/namespace::node()');
+ERROR: XMLTABLE cannot cast a namespace node to a non-XML result type
-- used in prepare statements
PREPARE pp AS
SELECT xmltable.*
^
DETAIL: This functionality requires the server to be built with libxml support.
HINT: You need to rebuild PostgreSQL using --with-libxml.
+SELECT * FROM XMLTABLE('/'
+ PASSING '<foo/>'
+ COLUMNS a text PATH 'foo/namespace::node()');
+ERROR: unsupported XML feature
+LINE 2: PASSING '<foo/>'
+ ^
+DETAIL: This functionality requires the server to be built with libxml support.
+HINT: You need to rebuild PostgreSQL using --with-libxml.
-- used in prepare statements
PREPARE pp AS
SELECT xmltable.*
PASSING '<rows xmlns="http://x.y"><row><a>10</a></row></rows>'
COLUMNS a int PATH 'a');
ERROR: DEFAULT namespace is not supported
+SELECT * FROM XMLTABLE('/'
+ PASSING '<foo/>'
+ COLUMNS a text PATH 'foo/namespace::node()');
+ERROR: XMLTABLE cannot cast a namespace node to a non-XML result type
-- used in prepare statements
PREPARE pp AS
SELECT xmltable.*
PASSING '<rows xmlns="http://x.y"><row><a>10</a></row></rows>'
COLUMNS a int PATH 'a');
+SELECT * FROM XMLTABLE('/'
+ PASSING '<foo/>'
+ COLUMNS a text PATH 'foo/namespace::node()');
+
-- used in prepare statements
PREPARE pp AS
SELECT xmltable.*