Avoid failure when selecting a namespace node in XMLTABLE. 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) Branch ------ REL_10_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/9bf24768664be6faf79333e1d4d6d14a0d33587b Modified Files -------------- src/backend/utils/adt/xml.c | 7 ++++++- src/test/regress/expected/xml.out | 4 ++++ src/test/regress/expected/xml_1.out | 8 ++++++++ src/test/regress/expected/xml_2.out | 4 ++++ src/test/regress/sql/xml.sql | 4 ++++ 5 files changed, 26 insertions(+), 1 deletion(-)
